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1

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from April 1, 1985 to Sept. 30, 1985 under NASA grant NAS1-441 entitled direct solar pumped iodine laser amplifier. During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion of the parametric studies. In addition, the kinetic modeling of a solar pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) the radiation characteristics of solar simulator and the parametric characteristics of photodissociation iodine laser continuously pumped by a Vortek solar simulator; (2) kinetic modeling of a solar pumped iodine laser amplifier; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K. S.

1985-01-01

2

Direct solar-pumped iodine laser amplifier  

Microsoft Academic Search

This semiannual progress report covers the period from April 1, 1985 to Sept. 30, 1985 under NASA grant NAS1-441 entitled direct solar pumped iodine laser amplifier. During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion

K. S. Han

1985-01-01

3

Direct solar-pumped iodine laser amplifier  

NASA Astrophysics Data System (ADS)

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1987-02-01

4

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1987-01-01

5

Direct solar-pumped iodine laser amplifier  

Microsoft Academic Search

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for

Kwang S. Han; In Heon Hwang; Larry V. Stock

1989-01-01

6

Direct solar-pumped iodine laser amplifier  

Microsoft Academic Search

The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where

Kwang S. Han; In Heon Hwang

1990-01-01

7

Solar-pumped photodissociation iodine laser  

NASA Technical Reports Server (NTRS)

The scientific feasibility of a solar-pumped iodine photodissociation laser for space applications is under investigation. Recently, a 2-W CW output for more than one hour was achieved using n-C3F7I vapor as the laser material and a vortex-stabilized argon arc as the light source.

Lee, J. H.; Weaver, W. R.; Humes, D. H.; Williams, M. D.; Lee, M. H.

1986-01-01

8

Solar-pumped photodissociation iodine laser  

SciTech Connect

The scientific feasibility of a solar-pumped iodine photodissociation laser for space applications is under investigation. Recently, a 2-watt CW output for more than one hour was achieved using n-C/sub 3/F/sub 7/I vapor as the laser material and a vortex-stabilized argon arc as the light source.

Lee, J.H.; Weaver, W.R.; Humes, D.H.; Williams, M.D.; Lee, M.H.

1986-08-15

9

Solar-pumped photodissociation iodine laser @f|  

Microsoft Academic Search

The scientific feasibility of a solar-pumped iodine photodissociation laser for space applications is under investigation. Recently, a 2-watt CW output for more than one hour was achieved using n-C3F7I vapor as the laser material and a vortex-stabilized argon arc as the light source.

J. H. Lee; W. R. Weaver; D. H. Humes; M. D. Williams; M. H. Lee

1986-01-01

10

Direct solar-pumped iodine laser amplifier  

Microsoft Academic Search

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly

Kwang S. Han; K. H. Kim; L. V. Stock

1987-01-01

11

Direct solar-pumped iodine laser amplifier  

Microsoft Academic Search

A XeCl laser pumped iodine laser oscillator was developed which will be incorporated into the Master Oscillator Power Amplifier (MOPA) system. The developed XeCl laser produces output energy of about 60 mJ per pulse. The pulse duration was about 10 nsec. The kinetic model for the solar-pumped laser was refined and the algorithm for the calculation of a set of

Kwang S. Han; In Heon Hwang; Khong Hon Kim; Larry V. Stock

1988-01-01

12

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification.

Han, Kwang S.; Hwang, In Heon

1990-01-01

13

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for amplification of the center's Vortek solar simulator pumped iodine laser amplifier. A modeling effort was also pursued to explain the experimental results in the theoretical work. The amplification measurement of the solar simulator pumped iodine laser amplifier is the first amplification experiment on the continuously pumped amplifier. The small signal amplification of 5 was achieved for the triple pass geometry of the 15 cm long solar simulator pumped amplifier at the n-C3F7I pressure of 20 torr, at the flow velocity of 6 m/sec and at the pumping intensity of 1500 solar constants. The XeCl laser pumped iodine laser oscillator, which was developed in the previous research, was employed as the master oscillator for the amplification measurement. In the theoretical work, the rate equations of the amplifier was established and the small signal amplification was calculated for the solar simulator pumped iodine laser amplifier. The amplification calculated from the kinetic equations with the previously measured rate coefficients reveals very large disagreement with experimental measurement. Moreover, the optimum condition predicted by the kinetic equation is quite discrepant with that measured by experiment. This fact indicates the necessity of study in the measurement of rate coefficients of the continuously pumped iodine laser system.

Han, Kwang S.; Hwang, In Heon; Stock, Larry V.

1989-01-01

14

Direct solar-pumped iodine laser amplifier  

Microsoft Academic Search

In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its

Kwang S. Han; K. H. Kim; L. V. Stock

1986-01-01

15

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled 'Direct solar-pumped iodine laser amplifier'. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It was observed that the threshold pump-beam intensities for both Nd:YAG and Nd:Cr:GSGG crystals were about 1000 solar constants, and the cw laser operation of the Nd:Cr:GSGG crystal was more difficult than that of the Nd:YAG crystal under the solar-simulator pumping. The possibility of the Nd:Cr:GSGG laser operation with a fast continuously chopped pumping was also observed. In addition, good agreement between the theoretical calculations and the experimental data on the loss mechanisms of a flashlamp-pumped iodine laser at various fill pressures and various lasants was achieved.

Han, Kwang S.

1987-01-01

16

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

A XeCl laser pumped iodine laser oscillator was developed which will be incorporated into the Master Oscillator Power Amplifier (MOPA) system. The developed XeCl laser produces output energy of about 60 mJ per pulse. The pulse duration was about 10 nsec. The kinetic model for the solar-pumped laser was refined and the algorithm for the calculation of a set of rate equations was improved to increase the accuracy and the efficiency of the calculation. The improved algorithm was applied to explain the existing experimental data taken from a flashlamp pumped iodine laser for three kinds of lasants, i-C3F7I, n-C4F9I, and t-C4F9I. Various solid laser materials were evaluated for solar-pumping. The materials studied were Nd:YAG, Nd:YLF, and Cr:Nd:GSGG crystals. The slope efficiency of 0.17 percent was measured for the Nd:YLF near the threshold pump intensity which was 211 solar constants (29W/sq cm). The threshold pump intensity of the Nd:YAG was measured to be 236 solar constants (32W/sq cm) and the near-threshold slope efficiency was 0.12 percent. True CW laser operation of Cr:Nd:GSGG was possible only at pump intensities less than or equal to 1,500 solar constants (203 W/sq cm). This fact was attributed to the high thermal focusing effect of the Cr:Nd:GSGG rod.

Han, Kwang S.; Hwang, In Heon; Kim, Khong Hon; Stock, Larry V.

1988-01-01

17

Optically (solar) pumped oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

We present the results of theoretical and experimental studies demonstrating the possibility of developing an oxygen-iodine laser (OIL) with direct optical pumping of molecular oxygen involving inter-molecular interaction with charge transfer from donor molecule (buffer gas) to acceptor molecule (oxygen). This interaction lifts degeneracy of the lower energy states of molecular oxygen and increases its absorption cross section in the visible spectral region and the UV Herzberg band, where high quantum yield of singlet oxygen is achieved (QY ˜ 1 and QY ˜ 2, respectively) at the same time. A pulse-periodic optical pump sources with pulse energy of ˜50 kJ, pulse duration of ˜25 ?s, and repetition rate of ˜10 Hz, which are synchronized with the mechanism of singlet oxygen generation, are developed. This allows implementation of a pulse-periodic oxygen-iodine laser with an efficiency of ˜25%, optical efficiency of ˜40%, and parameter L/ T ˜ 1/1.5, where T is the thermal energy released in the laser active medium upon generation of energy L. It is demonstrated that, under direct solar pumping of molecular oxygen, the efficiency parameter of the OIL can reach L/ T ˜ 1/0.8 in a wide range of scaling factors.

Danilov, O. B.; Zhevlakov, A. P.; Yur'ev, M. S.

2014-07-01

18

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its good utilization of the solar spectrum and high quantum efficiency. The measurement shows that a solar concentration of 20,000 is required to reach the threshold of the dye. The work to construct a kinetic model algorithm which predicts the output parameter of laser was progressed. The kinetic model was improved such that there is good agreement between the theoretical model and experimental data for the systems defined previously as flashlamp pumped laser oscillator, and the long path length solar pumped laser.

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1986-01-01

19

Low threshold solar-pumped iodine laser  

Microsoft Academic Search

Solar-pumped lasing of i-C3F7I and n-C4F9I at lower solar concentrations (170 solar constants) and longer gain lengths than previous solar lasers is demonstrated, with potential application to the lasing needs of space. Two xenon arc solar simulators provide an AM0 spectrum over the 60-cm gain length, and output pulse energies of 70 mJ and an average power of 550 mW

R. J. Deyoung

1986-01-01

20

Solar-pumped photodissociation iodine laser@f|  

Microsoft Academic Search

The scientific feasibility of a solar-pumped iodine photodissociation laser for space applications is under investigation. Recently, a 2-watt CW output for more than one hour was achieved using n-C3F7I vapor as the laser material and a vortex-stabilized argon arc as the light source.

J. H. Lee; W. R. Weaver; D. H. Humes; M. D. Williams; M. H. Lee

1986-01-01

21

Low threshold solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

Solar-pumped lasing of i-C3F7I and n-C4F9I at lower solar concentrations (170 solar constants) and longer gain lengths than previous solar lasers is demonstrated, with potential application to the lasing needs of space. Two xenon arc solar simulators provide an AM0 spectrum over the 60-cm gain length, and output pulse energies of 70 mJ and an average power of 550 mW are achieved. Low pressure lasing times of 600 ms are reached, and the observed 0.074 percent slope efficiency could approach the 0.2 percent maximum theoretical efficiency. Due to less quenching of I(asterisk), n-C4F9I is found to be a superior lasant to i-C3F7I.

Deyoung, R. J.

1986-01-01

22

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

A XeCl laser which was developed earlier for an iodine laser oscillator was modified in order to increase the output pulse energy of XeCl laser so that the iodine laser output energy could be increased. The electrical circuit of the XeCl laser was changed from a simple capacitor discharge circuit of the XeCl laser to a Marx system. Because of this improvement the output energy from the XeCl laser was increased from 60 mj to 80 mj. Subsequently, iodine laser output energy was increased from 100 mj to 3 mj. On the other hand, the energy storage capability and amplification characteristics of the Vortek solar simulator-pumped amplifier was calculated expecting the calculated amplification factor is about 2 and the energy extraction efficiency is 26 percent due to the very low input energy density to the amplifier. As a result of an improved kinetic modeling for the iodine solar simulator pumped power amplifier, it is found that the I-2 along the axis of the tube affects seriously the gain profile. For the gas i-C3F7I at the higher pressures, the gain will decrease due to the I-2 as the pumping intensity increases, and at these higher pressures an increase in flow velocity will increase the gain.

Han, Kwang S.; Hwang, In H.; Stock, Larry V.

1988-01-01

23

Low threshold solar-pumped iodine laser  

SciTech Connect

Solar-pumped lasing of i-C/sub 3/F/sub 7/I and n-C/sub 4/F/sub 9/I has been achieved at very low threshold pumping powers (170 solar constants) using a long (60 cm) gain length box laser configuration. Two xenon arc solar simulators were used to provide an AMO spectrum over the 60 cm gain length. Maximum pulse energy of 73mJ and average power of 525 mW were achieved at 7.3kW optical input. A slope efficiency of 0.074 percent was measured, the maximum theoretical efficiency being 0.2 percent. Longer gain lengths allow reduced optical input concentration, thus making the solar trough collector feasible for space applications. n-C/sub 4/F/sub 9/I was found to have less quenching of I*, making it a superior lasant to i-C/sub 3/F/sub 7/I.

DeYoung, R.J.

1986-07-01

24

Direct solar-pumped iodine laser amplifier. Semiannual Progress Report, 1 April30 September 1985  

Microsoft Academic Search

During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion of the parametric studies. In addition, the kinetic modeling of a solar pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser

Han

1985-01-01

25

Modeling of a solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

The direct conversion in space of solar radiation into laser radiation for power transmission to earth, satellites, or deep space probes shows promise as a reasonably simple technology and may have cost advantage in deployment and greater reliability compared to other methods of space power generation and transmission. The main candidates for solar pumping are the gas dynamic, photochemical, and direct photoexcited lasers. Here consideration is given to the photochemical reaction of alkyliodides which predominantly excite the I(2P1/2) state which then lases at 1.315 microns. The iodine ground state is eventually lost to reconstituting the gas or in the formation of molecular iodine. The rates at which the gas is required to be recycled through the laser system are modest. The side exposure at 100-fold solar concentration of a 100-m long tube with a 1 sq m cross section is estimated to provide 20 kW of continuous laser output. Scaling laws and optimum operating conditions of this system are discussed.

Wilson, J. W.; Lee, J. H.

1980-01-01

26

Modeling of a solar-pumped iodine laser  

Microsoft Academic Search

The direct conversion in space of solar radiation into laser radiation for power transmission to earth, satellites, or deep space probes shows promise as a reasonably simple technology and may have cost advantage in deployment and greater reliability compared to other methods of space power generation and transmission. The main candidates for solar pumping are the gas dynamic, photochemical, and

J. W. Wilson; J. H. Lee

1980-01-01

27

Modeling of a solar-pumped iodine laser  

Microsoft Academic Search

The direct conversion in space of solar radiation into laser radiation for power transmission to earth, satellites, or deep space probes shows promise as a reasonably simple technology and may have cost advantage in deployment and greater reliability compared to other methods of space power generation and transmission. The main candidates for solar pumping are the gas dynamic, photochemical, and

J. W. Wilson; J. H. Lee

2009-01-01

28

Direct solar-pumped iodine laser amplifier. Semiannual Progress Report, 1 April-30 September 1985  

SciTech Connect

During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion of the parametric studies. In addition, the kinetic modeling of a solar pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) the radiation characteristics of solar simulator and the parametric characteristics of photodissociation iodine laser continuously pumped by a Vortek solar simulator; (2) kinetic modeling of a solar pumped iodine laser amplifier; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K.S.

1985-09-01

29

Direct solar-pumped lasers  

NASA Technical Reports Server (NTRS)

The feasibility of direct solar pumping of an iodine photodissociation laser at lambda = 1.315 microns was investigated. Threshold inversion density and effect of elevated temperature (up to 670 K) on the laser output were measured. These results and the concentration of solar radiation required for the solar pumped iodine laser are discussed.

Lee, J. H.; Shiu, Y. J.; Weaver, W. R.

1980-01-01

30

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 October 1985-30 March 1986  

Microsoft Academic Search

During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator were carried out before amplifier studies. The amplifier studies are postponed to the extended period after completing the parametric studies. In addition, the kinetic modeling of a solar-pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in

Han

1986-01-01

31

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March30 September 1987  

Microsoft Academic Search

This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled Direct solar-pumped iodine laser amplifier. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It

Han

1987-01-01

32

A kinetic model for a solar-pumped iodine laser  

Microsoft Academic Search

Good agreement between the theoretical predictions and the experimental data is found for a flashlamp-pumped iodine laser for different fill pressures and different lasants (i-C3F7I, n-C4F9I, and t-C4F9I). The following loss mechanisms of the laser output power have been identified: a relatively large amount of initial molecular iodine in the fill gas and laser light scattering as a function of

L. V. Stock; J. W. Wilson

1988-01-01

33

Direct solar-pumped iodine laser amplifier. Final report, 1 March 1984-28 February 1990  

Microsoft Academic Search

The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where

K. S. Han; I. H. Hwang

1990-01-01

34

Amplified spontaneous emission in solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

The amplified spontaneous emission (ASE) from a long pulse, solar-simulating radiation pumped iodine laser amplifier is studied. The ASE threshold pump intensity is almost proportional to the inverse of the laser gain length when the gas pressure is constant in the laser tube.

Cho, Yong S.; Hwang, In H.; Han, Kwang S.; Lee, Ja H.

1992-01-01

35

A kinetic model for a solar-pumped iodine laser  

SciTech Connect

Good agreement between the theoretical predictions and the experimental data is found for a flashlamp-pumped iodine laser for different fill pressures and different lasants ({ital i}-C{sub 3}F{sub 7}I, {ital n}-C{sub 4}F{sub 9}I, and {ital t}-C{sub 4}F{sub 9}I). The following loss mechanisms of the laser output power have been identified: a relatively large amount of initial molecular iodine in the fill gas and laser light scattering as a function of pressure.

Stock, L.V. (Hampton University, Hampton, VA 23668 (US)); Wilson, J.W. (NASA, Langley Research Center, Hampton, VA 23665)

1988-10-01

36

Direct solar-pumped iodine laser amplifier. Final report, 1 March 1984-28 February 1990  

SciTech Connect

The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification.

Han, K.S.; Hwang, I.H.

1990-03-01

37

A 50kW module power station of directly solar-pumped iodine laser  

Microsoft Academic Search

The conceptual design of a 50 kW directly solar-pumped iodine laser (DSPIL) module was developed for a space-based power station which transmits its coherent-beam power to users such as the moon, Martian rovers, or other satellites with large (>25 kW) electric power requirements. Integration of multiple modules would provide an amount of power that exceeds the power of a single

S. H. Choi; J. H. Lee; W. E. Meador; E. J. Conway

1997-01-01

38

Directly solar-pumped iodine laser for beamed power transmission in space  

Microsoft Academic Search

A new approach for development of a 50-kW directly solar-pumped iodine laser (DSPIL) system as a space-based power station was made using a confocal unstable resonator (CUR). The CUR-based DSPIL has advantages, such as performance enhancement, reduction of total mass, and simplicity which alleviates the complexities inherent in the previous system, master oscillator\\/power amplifier (MOPA) configurations. In this design, a

S. H. Choi; W. E. Meador; J. H. Lee

1992-01-01

39

A long-pulse amplifier for solar-pumped iodine lasers  

NASA Technical Reports Server (NTRS)

The characteristics of a photodissociation iodine-laser amplifier pumped with a solar-simulating radiation were studied. Under long-pulse energy extraction, an energy amplification of about three and an energy storage time of longer than 500 microseconds were observed for a one meter long, 10 mm i.d. amplifier tube. The effects of elevated temperatures resulted in little reduction of the amplifier gain. These results confirm that developing an efficient chain of oscillator-amplifiers for a high-power solar-pumped iodine laser is indeed feasible.

Hwang, I. H.; Lee, J. H.; Lee, M. H.

1986-01-01

40

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 October 1985-30 March 1986  

SciTech Connect

During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator were carried out before amplifier studies. The amplifier studies are postponed to the extended period after completing the parametric studies. In addition, the kinetic modeling of a solar-pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) a 10 W CW iodine laser pumped by a Vortek solar simulator; (2) kinetic modeling to predict the time to lasing threshold, lasing time, and energy output of solar-pumped iodine laser; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K.S.

1986-03-01

41

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 September 1986-28 February 1987  

SciTech Connect

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

Han, K.S.; Kim, K.H.; Stock, L.V.

1987-02-01

42

Perfluorobutyl iodides as gain media for a solar-pumped iodine laser amplifier  

Microsoft Academic Search

The effectiveness of t-C4F9I and n-C4F9I as gain media for a space-based solar-pumped iodine photodissociation laser is investigated experimentally. The optically coupled flashlamp\\/amplifier-tube apparatus described by Hwang et al. (1986) is employed, driving the amplifier with 4-microsec 4.2-mJ TEM(00) pulses from a flashlamp-pumped laser oscillator; the variation of amplification with energy-extraction time was monitored by inserting a delay of up

Bagher M. Tabibi; Min H. Lee; Ja H. Lee; Willard R. Weaver

1987-01-01

43

Beam profile measurement of a solar-pumped iodine laser  

Microsoft Academic Search

Beam profile measurements have been made as a fuction of time within the laser pulse and CâFâI pressure. Measurements indicate that the profile is determined directly by the optical excitation volume, produced by the solar simulator, and that media distortion plays a minor role compared to the build up of quenching species during the lasing pulse.

De Young

1986-01-01

44

Beam profile measurement of a solar-pumped iodine laser  

SciTech Connect

Beam profile measurements have been made as a fuction of time within the laser pulse and C/sub 2/F/sub 5/I pressure. Measurements indicate that the profile is determined directly by the optical excitation volume, produced by the solar simulator, and that media distortion plays a minor role compared to the build up of quenching species during the lasing pulse.

De Young, R.J.

1986-11-01

45

Beam profile measurement of a solar-pumped iodine laser.  

PubMed

Beam profile measurements have been made as a function of time within the laser pulse and C2F5I pressure. Measurements indicate that the profile is determined directly by the optical excitation volume, produced by the solar simulator, and that media distortion plays a minor role compared to the build up of quenching species during the lasing pulse. PMID:18235707

De Young, R J

1986-11-01

46

Beam profile measurement of a solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

Beam profile measurements have been made as a function of time within the laser pulse and C2F5I pressure. Measurements indicate that the profile is determined directly by the optical excitation volume, produced by the solar simulator, and that media distortion plays a minor role compared to the build up of quenching species during the lasing pulse.

De Young, Russell J.

1986-01-01

47

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 September 1988-28 February 1989  

Microsoft Academic Search

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for

K. S. Han; I. H. Hwang; L. V. Stock

1989-01-01

48

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March31 August 1986  

Microsoft Academic Search

In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its

K. S. Han; K. H. Kim; L. V. Stock

1986-01-01

49

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March-30 September 1987  

SciTech Connect

This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled Direct solar-pumped iodine laser amplifier. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It was observed that the threshold pump-beam intensities for both Nd:YAG and Nd:Cr:GSGG crystals were about 1000 solar constants, and the cw laser operation of the Nd:Cr:GSGG crystal was more difficult than that of the Nd:YAG crystal under the solar-simulator pumping. The possibility of the Nd:Cr:GSGG laser operation with a fast continuously chopped pumping was also observed. In addition, good agreement between the theoretical calculations and the experimental data on the loss mechanisms of a flashlamp-pumped iodine laser at various fill pressures and various lasants was achieved.

Han, K.S.

1987-10-01

50

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 September 1986-28 February 1987  

Microsoft Academic Search

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly

K. S. Han; K. H. Kim; L. V. Stock

1987-01-01

51

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers  

NASA Technical Reports Server (NTRS)

Research is directed toward the design and synthesis of new media for solar-pumped I* lasers. Since the most effective existing lasants are perfluoroalkyl iodides, a strategy was proposed for the development of improved materials of this type with absorption maxima at 300 nm. Absorption spectra were synthesized and measured for prototypical species containing iodine bound to boron, iron, and cobalt.

Shiner, Christopher S.

1986-01-01

52

Directly solar-pumped iodine laser for beamed power transmission in space  

NASA Technical Reports Server (NTRS)

A new approach for development of a 50-kW directly solar-pumped iodine laser (DSPIL) system as a space-based power station was made using a confocal unstable resonator (CUR). The CUR-based DSPIL has advantages, such as performance enhancement, reduction of total mass, and simplicity which alleviates the complexities inherent in the previous system, master oscillator/power amplifier (MOPA) configurations. In this design, a single CUR-based DSPIL with 50-kW output power was defined and compared to the MOPA-based DSPIL. Integration of multiple modules for power requirements more than 50-kW is physically and structurally a sound approach as compared to building a single large system. An integrated system of multiple modules can respond to various mission power requirements by combining and aiming the coherent beams at the user's receiver.

Choi, S. H.; Meador, W. E.; Lee, J. H.

1992-01-01

53

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March-31 August 1986  

SciTech Connect

In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its good utilization of the solar spectrum and high quantum efficiency. The measurement shows that a solar concentration of 20,000 is required to reach the threshold of the dye. The work to construct a kinetic model algorithm which predicts the output parameter of laser was progressed. The kinetic model was improved such that there is good agreement between the theoretical model and experimental data for the systems defined previously as flashlamp pumped laser oscillator, and the long path length solar pumped laser.

Han, K.S.; Kim, K.H.; Stock, L.V.

1986-11-01

54

A 50-kW module power station of directly solar-pumped iodine laser  

SciTech Connect

The conceptual design of a 50 kW directly solar-pumped iodine laser (DSPIL) module was developed for a space-based power station which transmits its coherent-beam power to users such as the moon, Martian rovers, or other satellites with large (>25 kW) electric power requirements. Integration of multiple modules would provide an amount of power that exceeds the power of a single module by combining and directing the coherent beams to the user`s receiver. The model developed for the DSPIL system conservatively predicts the laser output power (50 kW) that appears much less than the laser output (93 kW) obtained from the gain volume ratio extrapolation of experimental data. The difference in laser outputs may be attributed to reflector configurations adopted in both design and experiment. Even though the photon absorption by multiple reflections in experimental cavity setup was more efficient, the maximum secondary absorption amounts to be only 24.7 percent of the primary. However, the gain volume ratio shows 86 percent more power output than theoretical estimation that is roughly 60 percent more than the contribution by the secondary absorption. Such a difference indicates that the theoretical model adopted in the study underestimates the overall performance of the DSPIL. This fact may tolerate more flexible and radical selection of design parameters than used in this design study. The design achieves an overall specific power of approximately 5 W/kg and total mass of 10 metric tons.

Choi, S.H.; Lee, J.H.; Meador, W.E.; Conway, E.J. [NASA Langley Research Center, Hampton, VA (United States)

1997-11-01

55

Perfluorobutyl iodides as gain media for a solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

The effectiveness of t-C4F9I and n-C4F9I as gain media for a space-based solar-pumped iodine photodissociation laser is investigated experimentally. The optically coupled flashlamp/amplifier-tube apparatus described by Hwang et al. (1986) is employed, driving the amplifier with 4-microsec 4.2-mJ TEM(00) pulses from a flashlamp-pumped laser oscillator; the variation of amplification with energy-extraction time was monitored by inserting a delay of up to 1 msec between the firing of the two flashlamps and measuring the delay between the optical pulses. The results are presented graphically and briefly characterized. The performance of t-C4F9I is found to be better than that of n-C4F9I (or n-C3F7I), with an absorption band shifted toward the visible (for improved utilization of solar radiation), higher gain (by a factor of 2) at all delay times, and better chemical reversibility. The gain did not depend significantly on temperature in any of the iodides.

Tabibi, Bagher M.; Lee, Min H.; Lee, Ja H.; Weaver, Willard R.

1987-01-01

56

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 September 1988-28 February 1989  

SciTech Connect

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for amplification of the center's Vortek solar simulator pumped iodine laser amplifier. A modeling effort was also pursued to explain the experimental results in the theoretical work. The amplification measurement of the solar simulator pumped iodine laser amplifier is the first amplification experiment on the continuously pumped amplifier. The small signal amplification of 5 was achieved for the triple pass geometry of the 15 cm long solar simulator pumped amplifier at the n-C3F7I pressure of 20 torr, at the flow velocity of 6 m/sec and at the pumping intensity of 1500 solar constants. The XeCl laser pumped iodine laser oscillator, which was developed in the previous research, was employed as the master oscillator for the amplification measurement. In the theoretical work, the rate equations of the amplifier was established and the small signal amplification was calculated for the solar simulator pumped iodine laser amplifier. The amplification calculated from the kinetic equations with the previously measured rate coefficients reveals very large disagreement with experimental measurement. Moreover, the optimum condition predicted by the kinetic equation is quite discrepant with that measured by experiment. This fact indicates the necessity of study in the measurement of rate coefficients of the continuously pumped iodine laser system.

Han, K.S.; Hwang, I.H.; Stock, L.V.

1989-02-01

57

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March31 August 1988  

Microsoft Academic Search

A XeCl laser which was developed earlier for an iodine laser oscillator was modified in order to increase the output pulse energy of XeCl laser so that the iodine laser output energy could be increased. The electrical circuit of the XeCl laser was changed from a simple capacitor discharge circuit of the XeCl laser to a Marx system. Because of

K. S. Han; I. H. Hwang; L. V. Stock

1988-01-01

58

High-power, continuously solar pumped and Q-switched iodine laser  

SciTech Connect

A train of high power (up to 160 W) Q-switched pulses at up to 1 kHz were continuously produced from a CW solar-simulator pumped iodine laser system. The Q-switching was accomplished by a fast mechanical chopper in the laser cavity and is the first reported Q-switching of a CW iodine laser. The dependence of CW and Q-switched laser powers on parameters such as the iodide vapor pressure, the flow rate, and the chopper speed are discussed.

Lee, J.H.; Humes, D.H.; Weaver, W.R. (NASA Langley Research Center, Hampton, Virginia 23665 (US)); Tabibi, B.M. (Hampton University, Hampton, Virginia 23668)

1988-10-01

59

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March-31 August 1988  

SciTech Connect

A XeCl laser which was developed earlier for an iodine laser oscillator was modified in order to increase the output pulse energy of XeCl laser so that the iodine laser output energy could be increased. The electrical circuit of the XeCl laser was changed from a simple capacitor discharge circuit of the XeCl laser to a Marx system. Because of this improvement the output energy from the XeCl laser was increased from 60 mj to 80 mj. Subsequently, iodine laser output energy was increased from 100 mj to 3 mj. On the other hand, the energy storage capability and amplification characteristics of the Vortek solar simulator-pumped amplifier was calculated expecting the calculated amplification factor is about 2 and the energy extraction efficiency is 26 percent due to the very low input energy density to the amplifier. As a result of an improved kinetic modeling for the iodine solar simulator pumped power amplifier, it is found that the I-2 along the axis of the tube affects seriously the gain profile. For the gas i-C3F7I at the higher pressures, the gain will decrease due to the I-2 as the pumping intensity increases, and at these higher pressures an increase in flow velocity will increase the gain.

Han, K.S.; Hwang, I.H.; Stock, L.V.

1988-10-01

60

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers. Semiannual progress report, 1 July-31 December 1986  

SciTech Connect

Research is directed toward the design and synthesis of new media for solar-pumped I* lasers. Since the most effective existing lasants are perfluoroalkyl iodides, a strategy was proposed for the development of improved materials of this type with absorption maxima at 300 nm. Absorption spectra were synthesized and measured for prototypical species containing iodine bound to boron, iron, and cobalt.

Shiner, C.S.

1986-12-01

61

A long-pulse amplifier for solar-pumped iodine lasers  

Microsoft Academic Search

The characteristics of a photodissociation iodine-laser amplifier pumped with a solar-simulating radiation were studied. Under long-pulse energy extraction, an energy amplification of about three and an energy storage time of longer than 500 microseconds were observed for a one meter long, 10 mm i.d. amplifier tube. The effects of elevated temperatures resulted in little reduction of the amplifier gain. These

I. H. Hwang; J. H. Lee; M. H. Lee

1986-01-01

62

Laser Doppler velocimetry for continuous flow solar-pumped iodine laser system  

NASA Technical Reports Server (NTRS)

A laser Doppler velocimetry (LDV) system was employed to measure the flow velocity profile of iodide vapor inside laser tubes of 36 mm ID and 20 mm ID. The LDV, which was operated in the forward scatter mode used a low power (15 mW) He-Ne laser beam. Velocity ranges from 1 m/s was measured to within one percent accuracy. The flow velocity profile across the laser tube was measured and the intensity of turbulence was determined. The flow of iodide inside the laser tube demonstrated a mixture of both turbulence and laminar flow. The flowmeter used for the laser system previously was calibrated with the LDV and found to be in good agreement.

Tabibi, Bagher M.; Lee, Ja H.

1991-01-01

63

Laser Doppler velocimetry for continuous flow solar-pumped iodine laser system  

Microsoft Academic Search

A laser Doppler velocimetry (LDV) system was employed to measure the flow velocity profile of iodide vapor inside laser tubes of 36 mm ID and 20 mm ID. The LDV, which was operated in the forward scatter mode used a low power (15 mW) He-Ne laser beam. Velocity ranges from 1 m\\/s was measured to within one percent accuracy. The

Bagher M. Tabibi; Ja H. Lee

1991-01-01

64

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers  

NASA Technical Reports Server (NTRS)

The design and chemical synthesis of new media for solar pumped iodine molecule lasers are explored. In an effort to prepare an iodo fluorocarbon compound absorbing strongly at 300 nm or above, the synthesis of perfluoro allylic iodides was investigated. These compounds furnish especially stable allylic radicals upon photodissociation. The desired red shift is anticipated in the absorption maximum could correlate with increasing radical stability. This expectation was based upon the analysis, previously reported, of the structures and absorption maxima of compounds studied earlier. A previously unknown substance was prepared, a prototypical target molecule, perfluoro-3-iodocyclopent-1-ene. It was obtained by reaction of perfluorocyclopentene with sulfur trioxide under the influence of antimony pentafluoride catalyst, followed by treatment of the resulting allylic fluorosulfonate with sodium iodide in sulfoland solvent. Preliminary data indicate that the absorption maximum for the iodo fluorocarbon is not shifted significantly to longer wavelength. It is not certain whether this result reflects an unexpected influence of the cyclic structure upon the position of the absorption maximum.

Shiner, C. S.

1986-01-01

65

Solar-pumped laser for free space power transmission  

NASA Technical Reports Server (NTRS)

Laser power transmission; laser systems; space-borne and available lasers; 2-D and 1 MW laser diode array systems; technical issues; iodine solar pumped laser system; and laser power transmission applications are presented. This presentation is represented by viewgraphs only.

Lee, Ja H.

1989-01-01

66

Solar Pumped Laser Microthruster  

NASA Astrophysics Data System (ADS)

The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

Rubenchik, A. M.; Beach, R.; Dawson, J.; Siders, C. W.

2010-10-01

67

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers  

NASA Technical Reports Server (NTRS)

This work is directed toward the design and chemical synthesis of new media for solar-pumped I* lasers. In view of the desirability of preparing a perfluoroalkyl iodide absorbing strongly at 300 nm, the relationship betwen perfluoroalkyl iodide structure and the corresponding absorption wavelength was reexamined. Analysis of existing data suggests that, in this family of compounds, the absorption maximum shifts to longer wavelength, as desired, as the C-I bond in the lasant is progressively weakened. Weakening of the C-I bond correlates, in turn, with increasing stability of the perfluoroalkyl radical formed upon photodissociation of the iodide. The extremely promising absorption characteristics of perfluoro-tert-butyl iodide can be accounted for on this basis. A new technique of diode laser probing to obtain precise yields of I* atoms in photodissociation was also developed.

Shiner, C. S.

1985-01-01

68

Solar Pumped Lasers and Their Applications  

NASA Technical Reports Server (NTRS)

Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

Lee, Ja H.

1991-01-01

69

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers. Semiannual progress report, 1 January-30 June 1986  

SciTech Connect

The design and chemical synthesis of new media for solar pumped iodine molecule lasers are explored. In an effort to prepare an iodo fluorocarbon compound absorbing strongly at 300 nm or above, the synthesis of perfluoro allylic iodides was investigated. These compounds furnish especially stable allylic radicals upon photodissociation. The desired red shift is anticipated in the absorption maximum could correlate with increasing radical stability. This expectation was based upon the analysis, previously reported, of the structures and absorption maxima of compounds studied earlier. A previously unknown substance was prepared, a prototypical target molecule, perfluoro-3-iodocyclopent-1-ene. It was obtained by reaction of perfluorocyclopentene with sulfur trioxide under the influence of antimony pentafluoride catalyst, followed by treatment of the resulting allylic fluorosulfonate with sodium iodide in sulfoland solvent. Preliminary data indicate that the absorption maximum for the iodo fluorocarbon is not shifted significantly to longer wavelength. It is not certain whether this result reflects an unexpected influence of the cyclic structure upon the position of the absorption maximum.

Shiner, C.S.

1986-01-01

70

Research on solar pumped liquid lasers  

NASA Technical Reports Server (NTRS)

A solar pumped liquid laser that can be scaled up to high power (10 mW CW) for space applications was developed. Liquid lasers have the advantage over gases in that they provide much higher lasant densities and thus high-power densities. Liquids also have advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13: Nd sup 3+:ZrC14 liquid was chosen for its high intrinsic efficiency and its relatively good stability against decomposition due to protic contamination. The development of a manufacturing procedure and performance testing of the laser, liquid and the development of an inexpensive large solar concentrator to pump the laser are examined.

Cox, J. D.; Kurzweg, U. H.; Weinstein, N. H.; Schneider, R. T.

1985-01-01

71

Solar-pumped gas laser development  

NASA Technical Reports Server (NTRS)

A survey of gas properties through detailed kinetic models led to the identification of critical gas parameters for use in choosing appropriate gas combinations for solar pumped lasers. Broadband photoabsorption in the visible or near UV range is required to excite large volumes of gas and to insure good solar absorption efficiency. The photoexcitation density is independent of the absorption bandwidth. The state excited must be a metastable state which is not quenched by the parent gas. The emission bandwidth must be less than 10 A to insure lasing threshold over reasonable gain lengths. The system should show a high degree of chemical reversibility and an insensitivity to increasing temperature. Other properties such as good quantum efficiency and kinetic efficiency are also implied. Although photoexcitation of electronic vibrational transitions is considered as a possible system if the emission bands sufficiently narrow, it appears that photodissociation into atomic metastables is more likely to result in a successful solar pumped laser system.

Wilson, J. W.

1980-01-01

72

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

Solar-pumped lasers were investigated by comparing experimental results from pulse experiments with steady state calculations. The time varying behavior of an IBr laser is studied. The analysis is only approximate, but indicates that conditions occurring in a pulsed experiment are quite different from those at steady state. The possibility of steady-state lasing in an IBr laser is determined. The effects of high temperatures on the quenching and recombination rates are examined. Although uncertainties in the values of the rate coefficients make it difficult to draw firm conclusions, it seems steady state running may be possible at high temperatures.

Harries, W. L.

1982-01-01

73

Theoretical studies of solar-pumped lasers  

SciTech Connect

Solar-pumped lasers were investigated by comparing experimental results from pulse experiments with steady state calculations. The time varying behavior of an IBr laser is studied. The analysis is only approximate, but indicates that conditions occurring in a pulsed experiment are quite different from those at steady state. The possibility of steady-state lasing in an IBr laser is determined. The effects of high temperatures on the quenching and recombination rates are examined. Although uncertainties in the values of the rate coefficients make it difficult to draw firm conclusions, it seems steady state running may be possible at high temperatures.

Harries, W.L.

1982-02-01

74

Photovoltaic converters for solar-pumped lasers  

NASA Technical Reports Server (NTRS)

The authors describe a mathematical parametric study of converters used to convert laser radiation to electricity for space-based laser power systems. Two different lasers, the 1.06-micron Nd laser and the 1.315-micron iodine laser, are used in the vertical junction converter. The calculated efficiency is 50 percent for a 100-junction Si photovoltaic converter when used with a Nd laser. The calculated efficiency for a 1000-junction Ga(0.53)In(0.47)As photovoltaic converter is 43 percent when used with an iodine laser.

Walker, Gilbert H.; Heinbockel, John H.

1988-01-01

75

Preliminary conceptual design and weight of a one-megawatt space-based laser power station utilizing a solar-pumped iodine lasant  

NASA Technical Reports Server (NTRS)

A preliminary conceptual design of a space-based solar-pumped iodide laser emitting 1 MW of laser power for space-to-space power transmission is described. A near-parabolic solar collector focuses sunlight onto the t-C4F9I lasant within a transverse-flow optical cavity. Using waste heat, a thermal system supplies compressor and auxiliary power. The major system components are designed with weight estimates assigned. In particular, it is found that laser efficiency is not a dominant weight factor, the dominant factor being the laser transmission optics. The station mass is 92,000 kg, requiring approximately eight Shuttle flights to LEO, where an orbital transfer vehicle can transport it to the final altitude of 6378 km.

De Young, R. J.; Walker, G. H.; Williams, M. D.; Schuster, G. L.; Conway, E. J.

1987-01-01

76

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers. Semiannual Progress Report, 1 January-30 June 1985  

SciTech Connect

This work is directed toward the design and chemical synthesis of new media for solar-pumped I* lasers. In view of the desirability of preparing a perfluoroalkyl iodide absorbing strongly at 300 nm, the relationship betwen perfluoroalkyl iodide structure and the corresponding absorption wavelength was reexamined. Analysis of existing data suggests that, in this family of compounds, the absorption maximum shifts to longer wavelength, as desired, as the C-I bond in the lasant is progressively weakened. Weakening of the C-I bond correlates, in turn, with increasing stability of the perfluoroalkyl radical formed upon photodissociation of the iodide. The extremely promising absorption characteristics of perfluoro-tert-butyl iodide can be accounted for on this basis. A new technique of diode laser probing to obtain precise yields of I* atoms in photodissociation was also developed.

Shiner, C.S.

1985-01-01

77

Perfluorobutyl iodides as gain media for a solar-pumped laser amplifier  

NASA Technical Reports Server (NTRS)

Perfluorobutyl iodides were studied as media for an iodine photodissociation laser amplifier, and photoabsorption cross sections were measured. The results indicate superior performance for t-C4F9I compared to that for n-C4F9I. The gain of n-C4F9I is found to be equal to that of n-C3F7I. The implications of these findings for space-based solar-pumped lasers are discussed.

Lee, Ja H.; Weaver, Willard R.; Tabibi, Bagher M.

1988-01-01

78

Solar pumped laser technology options for space power transmission  

NASA Technical Reports Server (NTRS)

An overview of long-range options for in-space laser power transmission is presented. The focus is on the new technology and research status of solar-pumped lasers and their solar concentration needs. The laser options include gas photodissociation lasers, optically-pumped solid-state lasers, and blackbody-pumped transfer lasers. The paper concludes with a summary of current research thrusts.

Conway, E. J.

1986-01-01

79

Overview and future direction for blackbody solar-pumped lasers  

NASA Technical Reports Server (NTRS)

A review of solar-pumped blackbody lasers is given which addresses their present status and suggests future research directions. The blackbody laser concept is one system proposed to scale to multimegawatt power levels for space-to-space power transmissions for such applications as onboard spacecraft electrical or propulsion needs. Among the critical technical issues are the scalability to high powers and the laser wavelength which impacts the transmission optics size as well as the laser-to-electric converter at the receiver. Because present blackbody solar-pumped lasers will have laser wavelengths longer than 4 microns, simple photovoltaic converters cannot be used, and transmission optics will be large. Thus, future blackbody laser systems should emphasize near visible laser wavelengths.

Deyoung, R. J.

1988-01-01

80

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

This report describes results of NASA Grant NAG-1-1148, entitled Direct Solar Pumping of Semiconductor Lasers: A Feasibility Study. The goals of this study were to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space with directly focused sunlight and to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or storage battery electrically pumping a current injection laser. With external modulation, such lasers could perhaps be efficient sources for intersatellite communications. We proposed specifically to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation at low pump intensities. These tasks have been accomplished, as described in this report of our completed project. The report is organized as follows: Some general considerations relevant to the solar-pumped semiconductor laser problem are discussed in Section 2, and the types of structures chosen for specific investigation are described. The details of the laser model we developed for this work are then outlined in Section 3. In Section 4, results of our study are presented, including designs for optimum lattice-matched and strained-layer solar-pumped quantum-well lasers and threshold pumping estimates for these structures. It was hoped at the outset of this work that structures could be identified which could be expected to operate continuously at solar photoexcitation intensities of several thousand suns, and this indeed turned out to be the case as described in this section. Our project is summarized in Section 5, and information on publications resulting from this work is provided in Section 6.

Anderson, Neal G.

1992-01-01

81

Design of ultrahigh brightness solar-pumped disk laser.  

PubMed

To significantly improve the solar-pumped laser beam brightness, a multi-Fresnel lens scheme is proposed for side-pumping either a single-crystal Nd:YAG or a core-doped ceramic Sm(3+) Nd:YAG disk. Optimum laser system parameters are found through ZEMAX and LASCAD numerical analysis. An ultrahigh laser beam figure of merit B of 53 W is numerically calculated, corresponding to a significant enhancement of more than 180 times over the previous record. 17.7 W/m(2) collection efficiency is also numerically attained. The strong thermal effects that have hampered present-day rod-type solar-pumped lasers can also be largely alleviated. PMID:22968278

Liang, Dawei; Almeida, Joana

2012-09-10

82

One-megawatt solar pumped and electrically driven lasers for space power transmission  

NASA Technical Reports Server (NTRS)

High power lasers in space could provide power for a variety of future space missions such as spacecraft electric power requirements and laser propulsion. This study investigates four electrically pumped laser systems, krypton fluoride, copper vapor, laser diode array, and the carbon dioxide laser, all scaled to 1-MW laser output. Each system obtained its primary power from a large solar photovoltaic array which, in turn, provides power for the appropriate laser power conditioning subsystem. Each system was block-diagrammed, and the power and efficiency were found for each subsystem. The laser diode array had the highest solar-to-laser efficiency (6 percent) and smallest radiator area making it the most advantageous of the electrically driven lasers studied. This system was then compared with an iodine solar pumped laser system previously studied. The diode array had a better wavelength with regard to transmission optics mass, but it also had a heavier radiator because of its lower temperature radiator requirement. A more advanced solar pumped laser could emerge as the preferred laser system for space applications.

Deyoung, R. J.; Lee, J. H.; Williams, M. D.; Schuster, G.; Conway, E. J.

1988-01-01

83

Solar-Pumped TEM?? Mode Nd:YAG laser.  

PubMed

Here we show a significant advance in solar-pumped laser beam brightness by utilizing a 1.0 m diameter Fresnel lens and a 3 mm diameter Nd:YAG single-crystal rod. The incoming solar radiation is firstly focused by the Fresnel lens on a solar tracker. A large aspheric lens and a 2D-CPC concentrator are then combined to further compress the concentrated solar radiation along the thin laser rod within a V-shaped pumping cavity. 2.3 W cw TEM?? (M² ? 1.1) solar laser power is finally produced, attaining 1.9 W laser beam brightness figure of merit, which is 6.6 times higher than the previous record. For multimode operation, 8.1 W cw laser power is produced, corresponding to 143% enhancement in collection efficiency. PMID:24150353

Liang, Dawei; Almeida, Joana

2013-10-21

84

Solar Pumped High Power Solid State Laser for Space Applications  

NASA Technical Reports Server (NTRS)

Highly coherent laser light provides a nearly optimal means of transmitting power in space. The simplest most direct means of converting sunlight to coherent laser light is a solar pumped laser oscillator. A key need for broadly useful space solar power is a robust solid state laser oscillator capable of operating efficiently in near Earth space at output powers in the multi hundred kilowatt range. The principal challenges in realizing such solar pumped laser oscillators are: (1) the need to remove heat from the solid state laser material without introducing unacceptable thermal shock, thermal lensing, or thermal stress induced birefringence to a degree that improves on current removal rates by several orders of magnitude and (2) to introduce sunlight at an effective concentration (kW/sq cm of laser cross sectional area) that is several orders of magnitude higher than currently available while tolerating a pointing error of the spacecraft of several degrees. We discuss strategies for addressing these challenges. The need to remove the high densities of heat, e.g., 30 kW/cu cm, while keeping the thermal shock, thermal lensing and thermal stress induced birefringence loss sufficiently low is addressed in terms of a novel use of diamond integrated with the laser material, such as Ti:sapphire in a manner such that the waste heat is removed from the laser medium in an axial direction and in the diamond in a radial direction. We discuss means for concentrating sunlight to an effective areal density of the order of 30 kW/sq cm. The method integrates conventional imaging optics, non-imaging optics and nonlinear optics. In effect we use a method that combines some of the methods of optical pumping solid state materials and optical fiber, but also address laser media having areas sufficiently large, e.g., 1 cm diameter to handle the multi-hundred kilowatt level powers needed for space solar power.

Fork, Richard L.; Laycock, Rustin L.; Green, Jason J. A.; Walker, Wesley W.; Cole, Spencer T.; Frederick, Kevin B.; Phillips, Dane J.

2004-01-01

85

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

The primary goals of the feasibility study are the following: (1) to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space directly focused sunlight; and (2) to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or battery electrically pumping a current injection laser. With external modulation, such lasers may prove to be efficient sources for intersatellite communications. We proposed to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation for operation at low pump intensities. This report outlines our progress toward these goals. Discussion of several technical details are left to the attached summary abstract.

Anderson, Neal G.

1991-01-01

86

Highly efficient solar-pumped Nd:YAG laser.  

PubMed

The recent progress in solar-pumped laser with Fresnel lens and Cr:Nd:YAG ceramic medium has revitalized solar laser researches, revealing a promising future for renewable reduction of magnesium from magnesium oxide. Here we show a big advance in solar laser collection efficiency by utilizing an economical Fresnel lens and a most widely used Nd:YAG single-crystal rod. The incoming solar radiation from the sun is focused by a 0.9 m diameter Fresnel lens. A dielectric totally internally reflecting secondary concentrator is employed to couple the concentrated solar radiation from the focal zone to a 4 mm diameter Nd:YAG rod within a conical pumping cavity. 12.3 W cw laser power is produced, corresponding to 19.3 W/m(2) collection efficiency, which is 2.9 times larger than the previous results with Nd:YAG single-crystal medium. Record-high slope efficiency of 3.9% is also registered. Laser beam quality is considerably improved by pumping a 3 mm diameter Nd:YAG rod. PMID:22274224

Liang, Dawei; Almeida, Joana

2011-12-19

87

Solar simulator-pumped atomic iodine laser  

SciTech Connect

An atomic iodine laser, a candidate for the direct solar-pumped gas laser, was excited with a 4-kW beam from a xenon arc solar simulator. Continuous lasing at 1.315 ..mu..m for over 10 ms was obtained for static filling of n-C/sub 3/F/sub 7/I vapor. By momentarily flowing the lasant, a 30-Hz pulsed output was obtained for about 200 ms. The peak laser power observed was 4 W for which the system efficiency reached 0.1%. These results indicate that direct solar pumping of a gas laser for power conversion in space is indeed feasible.

Lee, J.H.; Weaver, W.R.

1981-07-15

88

Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers  

NASA Technical Reports Server (NTRS)

The authors consider the relation between the threshold pumping intensity, the material properties, the resonator parameters, and the ultimate slope efficiencies of various solid-state laser materials for solar pumping. They clarify the relation between the threshold pump intensity and the material parameters and the relation between the ultimate slope efficiency and the laser resonator parameters such that a design criterion for the solar-pumped solid-state laser can be established. Among the laser materials evaluated, alexandrite has the highest slope efficiency of about 12.6 percent; however, it does not seem to be practical for a solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AM0) solar constants and its slope efficiency is about 12 percent when thermal deformation is completely prevented.

Hwang, In H.; Lee, Ja H.

1991-01-01

89

Low-threshold solar-pumped laser using C2F5I  

SciTech Connect

Solar-pumped lasing was achieved with pentafluoroethyl iodide, C2F5I, a new alkyl-iodide. Output power and energy of 350 mW and 45 mJ were achieved. This lasant was found to have the lowest lasing threshold of any solar-pumped gas laser to date at approximately 100 solar constants. Such low threshold enables the use in space of simple, trough solar collectors.

De Young, R.J.; Weaver, W.R.

1986-08-01

90

A solar pumped gas laser for the direct conversion of solar energy  

SciTech Connect

The first solar pumping of a gas laser scalable to high-power levels was achieved. The solar radiation was from a xenon arc solar simulator with a 4-kW beam power and a spectral distribution of air mass zero to an accuracy of about 20%. With the lasant n-heptafluoropropyl iodide (C/sub 3/F/sub 7/I), continuous lasing at 1.315 ..mu..m for over 10 ms and peak power output of 10 W were obtained for a single static fill. Numerical simulations based on the kinetics of the iodine laser match well the experimentally observed lasing features. The laser was also operated with quasisteady flow for up to 200 ms at a 30-Hz pulse rate indicating the feasibility of continual lasing by flowing the lasant. Since an equivalent pumping power is obtainable from a modest-sized collector only 2 m in diameter, this research indicates that solar energy can be transformed effectively directly into a continuous laser output which may be useful for extended space communications, powering deep space or near-Earth missions, and possibly even supplying energy to the Earth.

Weaver, E.E.; Lee, J.H.

1983-11-01

91

A solar simulator-pumped atomic iodine laser  

NASA Technical Reports Server (NTRS)

An atomic iodine laser, a candidate for the direct solar-pumped gas laser, was excited with a 4-kW beam from a xenon arc solar simulator. Continuous lasing at 1.315 micron for over 10 ms was obtained for static filling of n-C3F7I vapor. By momentarily flowing the lasant, a 30-Hz pulsed output was obtained for about 200 ms. The peak laser power observed was 4 W for which the system efficiency reached 0.1%. These results indicate that direct solar pumping of a gas laser for power conversion in space is indeed feasible.

Lee, J. H.; Weaver, W. R.

1981-01-01

92

A solar simulator-pumped atomic iodine laser  

Microsoft Academic Search

An atomic iodine laser, a candidate for the direct solar-pumped gas laser, was excited with a 4-kW beam from a xenon arc solar simulator. Continuous lasing at 1.315 micron for over 10 ms was obtained for static filling of n-C3F7I vapor. By momentarily flowing the lasant, a 30-Hz pulsed output was obtained for about 200 ms. The peak laser power

J. H. Lee; W. R. Weaver

1981-01-01

93

A solar simulator-pumped atomic iodine laser  

Microsoft Academic Search

An atomic iodine laser, a candidate for the direct solar-pumped gas laser, was excited with a 4-kW beam from a xenon arc solar simulator. Continuous lasing at 1.315 ?m for over 10 ms was obtained for static filling of n-C3F7I vapor. By momentarily flowing the lasant, a 30-Hz pulsed output was obtained for about 200 ms. The peak laser power

Ja H. Lee; W. R. Weaver

1981-01-01

94

High power CW iodine laser pumped by solar simulator  

NASA Technical Reports Server (NTRS)

An iodine photodissociation laser was pumped by a long Ar arc as the solar simulator to produce a 10-W CW output. Continuous lasing for 1 h was achieved with a flow of the laser material n-C3F7I. The 10-W CW output is the highest produced to date and establishes the feasibility of developing a solar-pumped laser for space power transmission.

Lee, Ja H.; Lee, Min H.; Weaver, Willard R.

1987-01-01

95

Low-threshold solar-pumped laser using C/sub 2/F/sub 5/I  

SciTech Connect

Solar-pumped lasing was achieved with pentafluoroethyl iodide, C/sub 2/F/sub 5/I, a new alkyl-iodide. Output power and energy of 350 mW and 45 mJ were achieved. This lasant was found to have the lowest lasing threshold of any solar-pumped gas laser to date at approximately 100 solar constants. Such low threshold enables the use in space of simple, trough solar collectors.

De Young, R.J.; Weaver, W.R.

1986-08-18

96

Simulation model of a new solar pumped laser system of Fresnel lens in Helwan of Egypt  

NASA Astrophysics Data System (ADS)

A simulation model of a new solar pumped laser system is tested to be run in Helwan in Egypt as an example of an industrial polluted area. The system is based on concentrating the solar radiation using a Fresnel lens on a laser head fixed on a mount tracking the sun during the day and powered by a DC battery. The model is fed by real solar radiation data in the various seasons in order to know the laser power got from such a system in those conditions. The results showed that the output laser power obtained from this system can be up to 6.2 W in spring, 6.8 W in summer, 2.2 W in autumn and 0.4 W in winter.

Abdel-Hadi, Yasser A.

2012-12-01

97

Flashlamp-pumped iodine monobromide laser characteristics  

NASA Technical Reports Server (NTRS)

The operating characteristics of a flashlamp-pumped IBr laser were investigated to evaluate its suitability for solar-pumped laser applications. A peak power of 350 W/sq cm at 2.7 microns was achieved at 12-torr IBr pressure. At 500-J flashlamp energy, the IBr output saturated; a gain of 0.17% per cm was measured for IBr. Neon was found to be effective for enhancing the recombination of the photodissociation products. With neon as a buffer gas, the laser pulse length was extended to 53 microsec. The termination of the laser pulse, within the flashlamp pulse, is thought to be due to the temperature rise in the gas. Increasing the IBr initial temperature decreased the lasing output. At 300 C, output dropped to approximately one-half the room temperature value. The dominant quencher is thought to be atomic iodine. IBr was found to couple better to the flashlamp energy than C3F7I.

Zapata, L. E.; De Young, R. J.

1983-01-01

98

Chemically pumped iodine laser  

Microsoft Academic Search

A chemically pumped iodine-atom laser is described based on electronic energy transfer to atomic iodine from chemically generated O2(1?). The total extracted power (10 W) is approximately 3% of the power contained in the O2(1?) flow.

R. J. Richardson; C. E. Wiswall

1979-01-01

99

Design of a high brightness solar-pumped laser by light-guides  

NASA Astrophysics Data System (ADS)

To improve solar-pumped laser output performance, a compact fused silica light-guide assembly is combined with a 2V-shaped cavity to achieve uniform pumping along a Nd:YAG rod. Based on both refractive and total internal reflection principles, the light-guide assembly provides an effective approach in both guiding and redistributing the highly concentrated solar radiation. A near Gaussian profile focal spot of a 1.5 m diameter parabolic mirror is transformed into an intense rectangular light column, uniformly distributed along the 2D-CPC output end of the assembly, avoiding the generation of hot pump spots within the laser rod. By trapping the pump light within the 2V-shaped cavity, efficient multi-pass absorption is achieved. Optimum pumping parameters and solar laser output powers are found through ZEMAX© non-sequential ray-tracing and LASCAD© laser cavity analysis. The solar laser output performances of both single-crystal and core-doped Nd:YAG rods are compared. Laser beam brightness figure of merit B=9.0×10-1 W is calculated, which is 310% more than the most recent record. About 16.4 W/m2 collection efficiency is also numerically predicted.

Almeida, J.; Liang, D.

2012-11-01

100

Design of high-brightness TEM00-mode solar-pumped laser for renewable material processing  

NASA Astrophysics Data System (ADS)

The conversion of sunlight into laser light by direct solar pumping is of ever-increasing importance because broadband, temporally constant, sunlight is converted into laser light, which can be a source of narrowband, collimated, rapidly pulsed, radiation with the possibility of obtaining extremely high brightness and intensity. Nonlinear processes, such as harmonic generation, might be used to obtain broad wavelength coverage, including the ultraviolet wavelengths, where the solar flux is very weak. The direct excitation of large lasers by sunlight offers the prospect of a drastic reduction in the cost of coherent optical radiation for high average power materials processing. This renewable laser has a large potential for many applications such as high-temperature materials processing, renewable magnesium-hydrogen energy cycle and so on. We propose here a scalable TEM00 mode solar laser pumping scheme, which is composed of four firststage 1.13 m diameter Fresnel lenses with its respective folding mirrors mounted on a two-axis automatic solar tracker. Concentrated solar power at the four focal spots of these Fresnel lenses are focused individually along a common 3.5 mm diameter, 70 mm length Nd:YAG rod via four pairs of second-stage fused-silica spherical lenses and third-stage 2D-CPCs (Compound Parabolic Concentrator), sitting just above the laser rod which is also double-pass pumped by four V-shaped pumping cavities. Distilled water cools both the rod and the concentrators. 15.4 W TEM00 solar laser power is numerically calculated, corresponding to 6.7 times enhancement in laser beam brightness.

Liang, D.; Almeida, J.

2014-08-01

101

Chemically pumped iodine laser  

Microsoft Academic Search

McDermott et al. (1978) have developed a practical O2(1 Delta) generator based on bubbling Cl2 in alkaline H2O2. In the work described in the present paper, it proved possible to convert a transverse-flow mixing chemical laser, originally designed as a CO chemical laser, to a chemical iodine-atom laser by installing a version of the McDermott generator on the laser. The

R. J. Richardson; C. E. Wiswall

1979-01-01

102

Analysis of a 10 megawatt space-based solar-pumped neodymium laser system  

NASA Technical Reports Server (NTRS)

A ten megawatt solar-pumped continuous liquid laser system for space applications is examined. It is found that a single inflatable mirror of 434 m diameter used in conjunction with a conical secondary concentrator is sufficient to side pump a liquid neodymium lasant in an annular tube of 6 m length and 1 m outer and 0.8 m inner diameter. About one fourth of intercepted radiation converging on the laser tube is absorbed and one fifth of this radiation is effective in populating the upper levels. The liquid lasant is flowed through the annular laser cavity at 1.9 m/s and is cooled via a heat exchanger and a large radiator surface comparable in size to the concentrating mirror. The power density of incident light within the lasant of approximately 68 watt/cu cm required for cw operation is exceeded in the present annular configuration. Total system weight corresponds to 20,500 kg and is thus capable of being transported to near Earth orbit by a single shuttle flight.

Kurweg, U. H.

1984-01-01

103

Optically pumped iodine monofluoride laser  

Microsoft Academic Search

In accordance with the present invention, there is provided a short wavelength chemical laser device which utilizes iodine monofluoride as a lasing medium. The device is an optically pumped iodine monofluoride laser in which the ground state iodine monofluoride is produced by reacting iodine and fluorine to form a flame within which the monofluoride is produced. The monofluoride is then

S. J. Davis; L. Hanko

1984-01-01

104

Advanced iodine laser concepts  

Microsoft Academic Search

The essential features of an advanced iodine laser are outlined. These are governed primarily by the proper choice of the stored inversion density of an amplifier and also by the means to enhance the energy extraction efficiency to values in excess of 50 percent. With these measures an amplifier chain with output energies in the kJ range and overall system

K. J. Witte; E. Fill; G. Brederlow; H. Baumhacker; R. Volk

1981-01-01

105

The atomic iodine photodissociation laser  

SciTech Connect

After almost two decades of laboratory research and development, the iodine photodissociation laser is now a developed system with industrial and scientific applications. This article reviews the progress of the iodine laser, the basic configuration and performance of a flashlamp-pumped system, and several applications areas. The major impetus behind the development of the iodine photodissociation laser (IPL) has been the requirement for a high-power, short-pulse, terawatt laser for laser fusion studies.

Bannister, J.J.; King, T.A.

1984-08-01

106

Iodine laser pumped by solar radiation  

SciTech Connect

An analysis is made of the use of solar radiation in space to pump a cw gas-flow iodine laser emitting at 1.3 ..mu... It is shown that the high probability of dissociation of I/sub 2/ molecules by solar radiation at an iodide vapor pressure of 0.25--0.5 kPa when the degree of concentration of solar radiation is 100--200 removes the constraint on the maximum duration of irradiation of the laser iodide associated with quenching of I(/sup 2/P/sub 1/2/) by I/sub 2/ molecules. In this case, the maximum duration of irradiation is governed by heating and pyrolysis. Numerical calculations and analytical estimates are used to analyze three variants of a solar-pumped iodine laser: using pure CF/sub 3/I iodide purified from I/sub 2/, using a CF/sub 3/I--(CF/sub 3/N)/sub 2/ mixture not purified from I/sub 2/, and using (CF/sub 3/)/sub 3/ CI not purified from I/sub 2/. Problems of circulation, purification, cooling, and irradiation of the active gas are examined.

Zalesskii, V.Y.

1983-06-01

107

Conversion of solar energy to laser beam by fullerene-oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The concept of a solar energy conversion into laser radiation on a basis of fullerene-oxygen-iodine laser (FOIL) is considered. A basis of FOIL construction is the photoexcitation of fullerene molecules into their triplet state by the sunlight, interaction of the photoexcited fullerene molecules with molecular oxygen with a singlet oxygen formation and subsequent transmission of the singlet oxygen energy to iodine atoms. Efficiency of the given process makes 30 % approximately. It is shown that for solar energy transformation to the laser radiation the singlet oxygen generator is under construction on the basis of solid-state porous fullerene-containing membranes. Results of working out and research of solid-state generators of singlet oxygen are presented. Constructive design of fullerene-oxygen-iodine laser of the continuous operating mode with the solar pumping for transformation of the sunlight to the laser beam for the decision of power problems are presented.

Belousova, I. M.; Danilov, O. B.; Kiselev, V. M.; Mak, A. A.

2011-03-01

108

Conversion of solar energy to laser beam by fullerene-oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The concept of a solar energy conversion into laser radiation on a basis of fullerene-oxygen-iodine laser (FOIL) is considered. A basis of FOIL construction is the photoexcitation of fullerene molecules into their triplet state by the sunlight, interaction of the photoexcited fullerene molecules with molecular oxygen with a singlet oxygen formation and subsequent transmission of the singlet oxygen energy to iodine atoms. Efficiency of the given process makes 30 % approximately. It is shown that for solar energy transformation to the laser radiation the singlet oxygen generator is under construction on the basis of solid-state porous fullerene-containing membranes. Results of working out and research of solid-state generators of singlet oxygen are presented. Constructive design of fullerene-oxygen-iodine laser of the continuous operating mode with the solar pumping for transformation of the sunlight to the laser beam for the decision of power problems are presented.

Belousova, I. M.; Danilov, O. B.; Kiselev, V. M.; Mak, A. A.

2010-07-01

109

Systems efficiency and specific mass estimates for direct and indirect solar-pumped closed-cycle high-energy lasers in space  

NASA Technical Reports Server (NTRS)

Based on expected advances in technology, the maximum system efficiency and minimum specific mass have been calculated for closed-cycle CO and CO2 electric-discharge lasers (EDL's) and a direct solar-pumped laser in space. The efficiency calculations take into account losses from excitation gas heating, ducting frictional and turning losses, and the compressor efficiency. The mass calculations include the power source, radiator, compressor, fluids, ducting, laser channel, optics, and heat exchanger for all of the systems; and in addition the power conditioner for the EDL's and a focusing mirror for the solar-pumped laser. The results show the major component masses in each system, show which is the lightest system, and provide the necessary criteria for solar-pumped lasers to be lighter than the EDL's. Finally, the masses are compared with results from other studies for a closed-cycle CO2 gasdynamic laser (GDL) and the proposed microwave satellite solar power station (SSPS).

Monson, D. J.

1978-01-01

110

Flashlamp-pumped iodine monobromide laser characteristics  

SciTech Connect

The operating characteristics of a flashlamp-pumped IBr laser were investigated to evaluate its suitability for solar-pumped laser applications. A peak power of 350 W/cm/sup 2/ at 2.7 ..mu..m was achieved at 12-Torr IBr pressure. At 500-J flashlamp energy, the IBr output saturated; a gain of 0.17% cm/sup -1/ was measured for IBr. Neon was found to be effective for enhancing the recombination of the photodissociation products. With neon as a buffer gas, the laser pulse length was extended to 53 ..mu..sec. The termination of the laser pulse, within the flashlamp pulse, is thought to be due to the temperature rise in the gas. Increasing the IBr initial temperature decreased the lasing output. At 300 /sup 0/C, output dropped to approximately one-half the room temperature value. The dominant quencher is thought to be atomic iodine. IBr was found to couple better to the flashlamp energy than C/sub 3/F/sub 7/I.

Zapata, L.E.; De Young, R.J.

1983-04-01

111

Model for the kinetics of a solar-pumped long path laser experiment  

SciTech Connect

A kinetic model for a solar-simulator pumped iodine laser system is developed and compared to an experiment in which the solar simulator output is dispersed over a large active volume (150 cu cm) with low simulator light intensity (approx. 200 solar constants). A trace foreign gas which quenches the upper level is introduced into the model. Furthermore, a constant representing optical absorption of the stimulated emission is introduced, in addition to a constant representing the scattering at each of the mirrors, via the optical cavity time constant. The non-uniform heating of the gas is treated as well as the pressure change as a function of time within the cavity. With these new phenomena introduced into the kinetic model, a best reasonable fit to the experimental data is found by adjusting the reaction rate coefficients within the range of known uncertainty by numerical methods giving a new bound within this range of uncertainty. The experimental parameters modeled are the lasing time, laser pulse energy, and time to laser threshold.

Stock, L.V.; Wilson, J.W.; Deyoung, R.J.

1986-05-01

112

REVIEW: Chemically pumped oxygen---iodine laser  

Microsoft Academic Search

A review is given of the principles of operation of the oxygen---iodine laser. Various types of chemical generators of singlet oxygen, which are key components in oxygen---iodine lasers, are considered. Experimental investigations of cw and pulsed oxygen---iodine lasers are described. The state-of-the-art theoretical investigations and potential applications of oxygen---iodine lasers are discussed.

Nikolai N. Yuryshev

1996-01-01

113

Preliminary design and cost of a 1-megawatt solar-pumped iodide laser space-to-space transmission station  

NASA Technical Reports Server (NTRS)

A preliminary conceptual design of a space-based solar pumped iodide laser emitting 1 megawatt of laser power for space-to-space power transmission is described. A near parabolic solar collector focuses sunlight onto the t-C4F9I (perfluoro-t butyl iodide) lasant within a transverse flow optical cavity. Using waste heat, a thermal system was designed to supply compressor and auxiliary power. System components were designed with weight and cost estimates assigned. Although cost is very approximate, the cost comparison of individual system components leads to valuable insights for future research. In particular, it was found that laser efficiency was not a dominant cost or weight factor, the dominant factor being the laser cavity and laser transmission optics. The manufacturing cost was approx. two thirds of the total cost with transportation to orbit the remainder. The flowing nonrenewable lasant comprised 20% of the total life cycle cost of the system and thus was not a major cost factor. The station mass was 92,000 kg without lasant, requiring approx. four shuttle flights to low Earth orbit where an orbital transfer vehicle will transport it to the final altitude of 6378 km.

Deyoung, R. J.; Walker, G. H.; Williams, M. D.; Schuster, G. L.; Conway, E. J.

1987-01-01

114

Preliminary design and cost of a 1-megawatt solar-pumped iodide laser space-to-space transmission station  

NASA Astrophysics Data System (ADS)

A preliminary conceptual design of a space-based solar pumped iodide laser emitting 1 megawatt of laser power for space-to-space power transmission is described. A near parabolic solar collector focuses sunlight onto the t-C4F9I (perfluoro-t butyl iodide) lasant within a transverse flow optical cavity. Using waste heat, a thermal system was designed to supply compressor and auxiliary power. System components were designed with weight and cost estimates assigned. Although cost is very approximate, the cost comparison of individual system components leads to valuable insights for future research. In particular, it was found that laser efficiency was not a dominant cost or weight factor, the dominant factor being the laser cavity and laser transmission optics. The manufacturing cost was approx. two thirds of the total cost with transportation to orbit the remainder. The flowing nonrenewable lasant comprised 20% of the total life cycle cost of the system and thus was not a major cost factor. The station mass was 92,000 kg without lasant, requiring approx. four shuttle flights to low Earth orbit where an orbital transfer vehicle will transport it to the final altitude of 6378 km.

Deyoung, R. J.; Walker, G. H.; Williams, M. D.; Schuster, G. L.; Conway, E. J.

1987-09-01

115

Dye laser pumped atomic iodine laser  

Microsoft Academic Search

Lasing has been demonstrated on the 2P1\\/2-2P3\\/2 transition in atomic iodine by optically pumping I2 vapor to dissociation with a flashlamp-pumped tunable dye laser. Lasing at 1.315 mu has been observed for pump wavelengths from 5010 to 4930 A˚. The device holds promise as a rapidly pulsed gain diagnostic for existing or future iodine systems.

S. J. Davis

1978-01-01

116

Dye laser pumped atomic iodine laser  

Microsoft Academic Search

Lasing has been demonstrated on the 2P1\\/2–2P3\\/2 transition in atomic iodine by optically pumping I2 vapor to dissociation with a flashlamp-pumped tunable dye laser. Lasing at 1.315 ? has been observed for pump wavelengths from 5010 to 4930 A?. The device holds promise as a rapidly pulsed gain diagnostic for existing or future iodine systems.

S. J. Davis

1978-01-01

117

Optically pumped iodine monofluoride laser  

SciTech Connect

This invention comprises an optically pumped iodine monofluoride laser operating on the B/sup 3/ ..pi.. (O/sup +/) ..-->.. X /SUP S/ ..sigma.. /sup +/ SYSTEM. Ground state IF was produced by the reaction beI/sub 2/ and F/sub 2/ in an optical cavity which was subsequently optically pumped with a high e00007600 broadband dye laser to produce lasing energy. 00007700

Davis, S. T.; Hanko, L.

1984-12-11

118

Perfluoro-n-hexyl iodide as gain media for high power, continuous solar-pumped lasers  

NASA Technical Reports Server (NTRS)

A comparative study of CW laser performance with n-C6F13I and n-C3F7I was performed using a 10-W solar-simulator-pumped laser system. The measured output power for n-C6F13I is near 10 W and is comparable to that of n-C3F7I. However, n-C6F13I has the advantages of easy purification and repeated use.

Lee, Ja H.; Tabibi, Bagher M.; Humes, Donald H.; Weaver, Willard R.

1990-01-01

119

Scalable chemical oxygen - iodine laser  

SciTech Connect

The problem of scaling chemical oxygen - iodine lasers (COILs) is discussed. The results of experimental study of a twisted-aerosol singlet oxygen generator meeting the COIL scalability requirements are presented. The energy characteristics of a supersonic COIL with singlet oxygen and iodine mixing in parallel flows are also experimentally studied. The output power of {approx}7.5 kW, corresponding to a specific power of 230 W cm{sup -2}, is achieved. The maximum chemical efficiency of the COIL is {approx}30%.

Adamenkov, A A; Bakshin, V V; Vyskubenko, B A; Efremov, V I; Il'in, S P; Ilyushin, Yurii N; Kolobyanin, Yu V; Kudryashov, E A; Troshkin, M V [Russian Federal Nuclear Center 'All-Russian Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod region (Russian Federation)

2011-12-31

120

Iodine dissociation in chemical oxygen-iodine lasers (COILs)  

Microsoft Academic Search

Iodine dissociation has been measured in the supersonic cavity of a chemical oxygen-iodine laser during lasing under a wide variety of flow conditions. By varying flow conditions, measured dissociations from 0 to 100 percent were observed. A simple model of the initial step in the dissociation process was developed that adequately rationalizes the measurements.

Charles A. Helms; J. Shaw; Gordon D. Hager; Keith A. Truesdell; David N. Plummer; J. Copland

1995-01-01

121

Iodine monofluoride discharge laser investigation  

SciTech Connect

The results of an experimental investigation to improve the performance of a discharge-pumped iodine monofluoride laser are reported. Lasing was observed at 478.7, 484.7, 490.7, and 496.5 nm. Electrical measurements of the discharge characteristics permitted the energy flow in the circuit to be followed and laser efficiencies to be calculated. Parametric studies of gas mixtures were carried out. By optimizing several parameters, single-pulse lasing energies greater than 50 mJ were obtained.

Harris, D.G.; Blauer, J.A.; Hurlock, S.C. (Rockwell International, Rocketdyne Division, Canoga Park, CA (USA))

1990-10-15

122

The high-power iodine laser  

SciTech Connect

This book covers the design and operation of pulsed high-power iodine lasers. Also examined are a large range of laser-produced plasma, beam quality and losses, the ASTERIX III system and the scalability and prospects of the iodine laser.

Brederlow, G.E.F.; Witte, K.J.

1983-01-01

123

Hyperfine relaxation in the iodine photodissociation laser  

Microsoft Academic Search

An experimental and analytical investigation is made of relaxation between the hyperfine sublevels of an iodine photodissociation laser. It is shown that the dominating mechanism in the upper laser level is a resonant exchange with iodine atoms in the ground state. A rate constant for relaxation in the upper level is determined along with an upper limit on the rate

W. Thieme; E. Fill

1981-01-01

124

CW optically pumped molecular iodine laser  

Microsoft Academic Search

Laser oscillation on several molecular iodine transitions is observed. The unique feature of this laser is that it is excited by a CW optical pump, a single longitudinal mode Ar(+) laser, and that it exhibits CW oscillation on more than 100 individually selectable transitions spanning more than one octave from 0.57 to 1.35 microns. The characteristics of the molecular-iodine laser

J. B. Koffend; F. J. Wodarczyk; R. W. Field

1978-01-01

125

Iodine photodissociation laser with plasma mirror  

Microsoft Academic Search

First experimental results with a pulsed iodine photodissociation laser controlled by target plasma reflectivity are reported. One of the laser mirrors is substituted for a focusing lens and a solid tilted target is located in its focal region. The laser dynamics depends on the geometry of the setup. Laser pulse durations from 200 to 5 ns were observed if the

J. Schmiedberger; M. Vrbova

1986-01-01

126

Development of a chemical oxygen - iodine laser with production of atomic iodine in a chemical reaction  

SciTech Connect

The alternative method of atomic iodine generation for a chemical oxygen - iodine laser (COIL) in chemical reactions with gaseous reactants is investigated experimentally. The influence of the configuration of iodine atom injection into the laser cavity on the efficiency of the atomic iodine generation and small-signal gain is studied. (lasers)

Censky, M; Spalek, O; Jirasek, V; Kodymova, J [Institute of Physics, Czech Academy of Sciences, Prague (Czech Republic); Jakubec, I [Institute of Inorganic Chemistry, Czech Academy of Sciences, Rez (Czech Republic)

2009-11-30

127

New iodine laser achieves positive gain  

Microsoft Academic Search

The chemical oxygen-iodine laser (COIL) is a continuous-wave, near-infrared chemical laser. It offers excellent properties for ap- plications that require high-power laser output from a mobile platform. The best-known example of a COIL system may be the 'Airborne Laser' ballistic missile defense weapon system,1 which uses a multi-megawatt laser with good beam quality. For very-high-power applications, chemical lasers retain the

Masamori Endo

2008-01-01

128

Short-pulse photolytic iodine laser  

Microsoft Academic Search

A compact, short pulse photolytic iodine laser (PIL) system designed for use as a source in Raman conversion experiments is described. The single-shot, flashlamp-pumped laser outputs 10 Joules in a 3 microsecond(s) FWHM pulse at a wavelength of 1.315 micrometer and uses n-C3F7I as the renewable laser fuel. Laser design and performance characteristics are presented.

Ralph F. Tate; Melvin Harris; Brian T. Anderson; Gordon D. Hager

2000-01-01

129

The chemically pumped oxygen-iodine laser  

Microsoft Academic Search

The present status of the chemical oxygen-iodine laser is discussed. The pertinent processes occurring in the chemical O2 generator, the O2(1Delta) transport region, and the nozzle are reviewed. The energy transfer kinetics, laser gain, and the performance and device efficiency are examined.

P. V. Avizonis; G. Hasen; K. A. Truesdell

1990-01-01

130

Iodine photodissociation laser system Perun II  

Microsoft Academic Search

A construction and exploitation of a medium size iodine photodissociation laser system Perun II is reported. This laser produced pulses of infrared light (?=1.315µm) up to 50 J in energy and 300 ps in duration. The diameter of the beam is 82 mm. The beam divergence is about 4×10-4 rad. The laser beam can be focused in a focal spot

M. Chvojka; B. Králiková; J. Krása; E. Krouský; L. Láska; K. Masek; O. Renner; K. Rohlena; J. Skála; O. Štirand; P. Trenda

1992-01-01

131

Continuous wave chemically pumped atomic iodine laser  

SciTech Connect

Cw laser action achieved on the 2p178-2p3/2 transition of the iodine atom by energy transfer from the 1 delta metastable state of O2 is discussed. The effluent from a conventional oxygen generator was mixed with molecular iodine at the entrance of a longitudinal flow laser cavity where the I2 was dissociated by a small amount of O2 (1 sigma ) that was present in the flow due to energy pooling processes. The measured output power was greater than 4MW

Benard, D.J.; Bousek, R.R.; Mcdermott, W.E.; Pchelkin, N.R.

1981-05-12

132

Characteristics of the electron beam pumped iodine monofluoride laser  

Microsoft Academic Search

Electron beam pumping of Ar\\/CFâI\\/NFâ mixtures yields optical pulse lengths about 0.5 ..mu..s from iodine monofluoride. Laser efficiency in this system is about0.04 percent. Laser performance is limited by the formation of molecular iodine. The formation of molecular iodine in the excited state (Iâ) reduces the number of iodine atoms available to form IF. In the ground state, molecular iodine

L. F. Champagne; J. E. Ehrlich

1983-01-01

133

ElectriCOIL: An Advanced Chemical Iodine Laser Concept  

Microsoft Academic Search

Advanced chemical iodine laser technology will logically include novel all gas phase generation techniques for an iodine energy donor and the injection of atomic rather than molecular iodine. Candidate methods are discussed for the creation of an all gas phase energy donor as well as for injecting atomic iodine. This research will lead directly to designs that will be fabricated

David L. Carroll; Wayne C. Solomon

2000-01-01

134

On kinetics of the photodissociation iodine laser  

Microsoft Academic Search

The kinetics of iodine laser amplifiers is examined by solving the time evolution equations of chemical kinetics during optical pumping. The pumping radiation intensity is modelled by a black body of the temperature varying in time (corresponding to the flash lamp pulse). A brief comparison is made of pumping effects by long and short light pulses. Pumping by the long

K. Rohlena; K. Masek; J. Kodymova; E. G. Balabanová; I. Pauli?ka; B. Stefanov

1985-01-01

135

A continuously pumped iodine laser amplifier  

Microsoft Academic Search

The amplification characteristics were studied for a continuously pumped iodine laser amplifier using n-C3F7I as the amplifying medium. A small-signal amplification of 5 was obtained from a 15 cm long amplifier pumped with 1000 AM0 solar radiation by passing the oscillator output through the amplifier three times.

In Heon Hwang; Kwang S. Han

1991-01-01

136

A model for a continuous-wave iodine laser  

SciTech Connect

A model for a continuous-wave (CW) iodine laser has been developed and compared with the experimental results obtained from a solar-simulator-pumped CW iodine laser. The agreement between the calculated laser power output and the experimental results is generally good for various laser parameters even when the model includes only prominent rate coefficients. The flow velocity dependence of the output power shows that the CW iodine laser cannot be achieved with a flow velocity below 1 m/s for the present solar-simulator-pumped CW iodine laser system.

Hwang, I.H.; Tabibi, B.M. (Department of Physics, Hampton Univiersity,Hampton, VA (USA) Spaceborne Photonics Institute, Hampton University,Hampton, VA (USA))

1990-11-15

137

A model for a continuous-wave iodine laser  

NASA Technical Reports Server (NTRS)

A model for a continuous-wave (CW) iodine laser has been developed and compared with the experimental results obtained from a solar-simulator-pumped CW iodine laser. The agreement between the calculated laser power output and the experimental results is generally good for various laser parameters even when the model includes only prominent rate coefficients. The flow velocity dependence of the output power shows that the CW iodine laser cannot be achieved with a flow velocity below 1 m/s for the present solar-simulator-pumped CW iodine laser system.

Hwang, In H.; Tabibi, Bagher M.

1990-01-01

138

Characteristics of the electron beam pumped iodine monofluoride laser  

Microsoft Academic Search

Electron beam pumping of Ar\\/CF3I\\/NF3 mixtures yields optical pulse lengths approximately 0.5 microsec from iodine monofluoride. Laser efficiency in this system is approximately 0.04 percent. Laser performance is limited by the formation of molecular iodine. The formation of molecular iodine in the excited state reduces the number of iodine atoms available to form excited-state IF. In the ground state, molecular

L. F. Champagne; J. E. Ehrlich

1983-01-01

139

Output Power Enhancement of a Chemical Oxygen-Iodine Laser by Predissociated Iodine Injection  

Microsoft Academic Search

Output power enhancement of a chemical oxygen-iodine laser (COIL) by an injection of predissociated iodine was studied. Iodine molecules were dissociated into atoms by the microwave discharge prior to injection. It was determined that predissociation caused a negative effect on the output power enhancement when this technique was applied to a conventional supersonic COIL@. Model calculations revealed that the existence

Masamori Endo; Daichi Sugimoto; Hideo Okamoto; Kenzo Nanri; Taro Uchiyama; Shuzaburo Takeda; Tomoo Fujioka

2000-01-01

140

Chemical oxygen-iodine laser with a new method of atomic iodine generation  

Microsoft Academic Search

A study of recently proposed chemical method of atomic iodine production in the Chemical Oxygen-Iodine Laser (COIL) was performed. The process using gaseous reactants is based on the fast reaction of hydrogen iodide with chemically produced atomic chlorine. In the absence of singlet oxygen, the high yield of atomic iodine was attained (80 to 100 %). In the flow of

Otomar Spalek; Miroslav Censky; Vít Jirásek; Jarmila Kodymová; Ivo Jakubec; Gordon D. Hager

2003-01-01

141

Characteristics of the electron beam pumped iodine monofluoride laser  

SciTech Connect

Electron beam pumping of Ar/CF/sub 3/I/NF/sub 3/ mixtures yields optical pulse lengths about 0.5 ..mu..s from iodine monofluoride. Laser efficiency in this system is about0.04 percent. Laser performance is limited by the formation of molecular iodine. The formation of molecular iodine in the excited state (I/sub 2/) reduces the number of iodine atoms available to form IF. In the ground state, molecular iodine (I/sub 2/) absorbs the IF laser emission at 485 and 491 nm.

Champagne, L.F.; Ehrlich, J.E.

1983-02-01

142

Influence of an iodine donor on the output energy of a pulsed oxygen-iodine laser  

Microsoft Academic Search

The influence of atomic iodine donors (CH3I and CF3I) on the output energy of a pulsed oxygen-iodine laser was investigated. Their influence on the time dependence of the luminescence intensity of I (2P1\\/2) iodine atoms formed by laser photolysis of an RI–O2–M mixture (R = CH3, CF3, M is the buffer gas) was also studied. An analysis of the experimental

Nikolai P Vagin; V A Zolotarev; P G Kryukov; V S Pazyuk; Yu P Podmarkov; M P Frolov; Nikolai N Yuryshev

1991-01-01

143

Chemical generation of atomic iodine for chemical oxygen–iodine laser. I. Modelling of reaction systems  

Microsoft Academic Search

The mathematical modelling of reaction systems for chemical generation of atomic iodine is presented. This process is aimed to be applied in the chemical oxygen–iodine laser (COIL), where it can save a substantial part of energy of singlet oxygen and so increase the laser output power. In the suggested method, gaseous reactants for I atoms generation are admixed into the

V??t Jirásek; Otomar Špalek; Jarmila Kodymová; Miroslav ?enský

2001-01-01

144

Feasibility of an iodine gas laser pumped by concentrated terrestrial solar radiation  

SciTech Connect

A t-C{sub 4}F{sub 9}I iodine gas laser pumped by terrestrial sunlight was analyzed. Lasant properties, spectral terrestrial insolation data, and established laser fundamentals were used to develop a mathematical model of a terrestrial solar-pumped system. Threshold pumping power and available terrestrial pumping power were predicted and used to estimate the solar concentration required to initiate lasing. Laser output power was also predicted. Because this lasant is relatively new and has never been pumped by solar radiation, many physical properties are not well known. An uncertainty analysis was used to predict errors in threshold solar concentration and output power. In all cases, conservative estimates of physical properties were used. The dominant uncertainty in both threshold and output predictions was due to wide variation in published values of the quenching reaction caused by the lasant parent molecule. Several optical and geometric configurations were devised using commercially available primary solar collectors: parabolic or compound parabolic troughs, a Shenandoah-type 7.5 meter diameter parabolic dishes, or a 17 meter diameter stretched membrane dish. Threshold solar concentration for these systems ranged from below 50 to almost 200 suns depending on the laser tube geometry. Output power ranged from below 1 Watt to almost 90 Watts, and was a function of primary collector dimension.

Terry, C.K.; Peterson, J.E.; Goswami, D.Y. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

1995-11-01

145

Electric oxygen-iodine laser discharge scaling and laser performance  

NASA Astrophysics Data System (ADS)

In 2004, a research partnership between the University of Illinois and CU Aerospace demonstrated the first electric discharge pumped oxygen-iodine laser referred to as ElectricOIL. This exciting improvement over the standard oxygen-iodine laser utilizes a gas discharge to produce the necessary electronically-excited molecular oxygen, O2(a 1Delta), that serves as the energy reservoir in the laser system. Pumped by a near-resonant energy transfer, the atomic iodine lases on the I(2P1/2) ? I(2P3/2) transition at 1315 nm. Molecular oxygen diluted with helium and a small fraction of nitric oxide flows through a radiofrequency discharge where O2(a 1Delta) and many other excited species are created. Careful investigations to understand the benefits and problems associated with these other states in the laser system allowed this team to succeed where other research groups had failed, and after the initial demonstration, the ElectricOIL research focus shifted to increasing the efficiencies along with the output laser energy. Among other factors, the laser power scales with the flow rate of oxygen in the desired excited state. Therefore, high yields of O2(a 1Delta) are desired along with high input oxygen flow rates. In the early ElectricOIL experiments, the pressure in the discharge was approximately 10 Torr, but increased flow rates forced the pressure to between 50 and 60 Torr requiring a number of new discharge designs in order to produce similar yields of O2(a1Delta) efficiently. Experiments were conducted with only the electric discharge portion of the laser system using emission diagnostics to study the effects of changing the discharge geometry, flow residence time, and diluent. The power carried by O2(a 1Delta) is the maximum power that could be extracted from the laser, and the results from these studies showed approximately 2500 W stored in the O2(a1Delta) state. Transferring this energy into the atomic iodine has been another challenge in ElectricOIL as experiments have shown that the iodine is pumped into the excited state slower than is predicted by the known kinetics, resulting in reduced output power. An elementary model is presented that may partially explain this problem. Larger laser resonator volumes are employed to improve power extraction by providing more flow time for iodine pumping. The results presented in this work in conjunction with the efforts of others led to ElectricOIL scaling from 200 mW in the initial demonstration to nearly 500 W.

Woodard, Brian S.

146

Chemical oxygen — iodine laser with mixing of supersonic jets  

Microsoft Academic Search

The results are reported of the first investigation of a chemical oxygen — iodine laser with supersonic mixing of parallel jets of oxygen and of a mixture of nitrogen with iodine. It was found that, in principle, such a laser system is feasible. The maximum output power was 160 and 130 W with the chemical efficiency 13% and 14.3%, respectively.

V N Azyazov; M V Zagidullin; V D Nikolaev; V S Safonov

1997-01-01

147

The standard chemical oxygen-iodine laser kinetics package  

Microsoft Academic Search

This report presents the Air Force Weapons Laboratory Standard Chemical Oxygen-Iodine Laser Kinetics Package. A complete reaction scheme including recommended rate coefficients for modeling the gas phase kinetics of chemical oxygen-iodine lasers (COIL) was established to provide a common basis for the research and development of COIL devices. A review of the experimental kinetic data base from which this model

Glen P. Perram; Gordon D. Hager

1988-01-01

148

Solar-simulator-pumped atomic iodine laser kinetics  

Microsoft Academic Search

The literature contains broad ranges of disagreement in kinetic data for the atomic iodine laser. A kinetic model of a solar-simulator-pumped iodine laser is used to select those kinetic data consistent with recent laser experiments at the Langley Research Center. Analysis of the solar-simulator-pumped laser experiments resulted in the following estimates of rate coefficients: for alkyl radical (n-C3F7) and atomic

H. W. Wilson; S. Raju; Y. J. Shiu

1983-01-01

149

Gain and continuous-wave laser power enhancement with a secondary discharge to predissociate molecular iodine  

E-print Network

molecular iodine in an electric oxygen-iodine laser G. F. Benavides,1 J. W. Zimmerman,2 B. S. Woodard,2 D. L and 38% enhancement in continuous-wave laser power on the 1315 nm transition of atomic iodine through the addition of a secondary discharge to predissociate the molecular iodine in an electric oxygen-iodine laser

Carroll, David L.

150

Chemical oxygen-iodine laser with atomic iodine generated via Cl or F atoms  

Microsoft Academic Search

Two alternative chemical methods of atomic iodine generation for a chemical oxygen-iodine laser (COIL) were studied. These methods are based on fast reactions of gaseous hydrogen iodide with chemically produced chlorine and fluorine atoms. Both processes were studied first in small-scale reactors. A yield of atomic iodine in the Cl system and nitrogen (non-reactive) atmosphere exceeded 80%, while in the

Otomar Spalek; Vit Jirasek; Miroslav Censky; Jarmila Kodymova; Ivo Jakubec; Gordon D. Hager

2005-01-01

151

Chemical generation of atomic iodine for the chemical oxygen–iodine laser. II. Experimental results  

Microsoft Academic Search

A new method for the chemical generation of atomic iodine intended for use in a chemical oxygen–iodine laser (COIL) was investigated experimentally. The method is based on the fast reaction of hydrogen iodide with chemically produced chlorine atoms. Effects of the initial ratio of reactants and their mixing in a flow of nitrogen were investigated experimentally and interpreted by means

Otomar Špalek; V??t Jirásek; Miroslav ?enský; Jarmila Kodymová; Ivo Jakubec; Gordon D. Hager

2002-01-01

152

Solar-simulator-pumped atomic iodine laser kinetics  

NASA Technical Reports Server (NTRS)

The literature contains broad ranges of disagreement in kinetic data for the atomic iodine laser. A kinetic model of a solar-simulator-pumped iodine laser is used to select those kinetic data consistent with recent laser experiments at the Langley Research Center. Analysis of the solar-simulator-pumped laser experiments resulted in the following estimates of rate coefficients: for alkyl radical (n-C3F7) and atomic iodine (I) recombination, 4.3 x 10 to the 11th power (1.9) + or - cu cm/s; for n-C3F7I stabilized atomic iodine recombination (I + I) 3.7 x 10 to the -32nd power (2.3) + or -1 cm to the 6th power/s; and for molecular iodine (I2) quenching, 3.1 x 10 to the -11th power (1.6) + or - 1 cu cm/s. These rates are consistent with the recent measurements.

Wilson, H. W.; Raju, S.; Shiu, Y. J.

1983-01-01

153

100 GW pulsed iodine photodissociation laser system PERUN I  

Microsoft Academic Search

The photodissociation iodine laser system PERUN I is described. The laser generates and amplifies the subnanosecond pulse with the energy about 80 J of the fundamental wavelength 1·315 µm and beam diameter 10 cm. The physical principles of this type of the high power laser are briefly explained and the laser system and its characteristics are described from the physical

M. Chvojka; V. Hermoch; B. Kralikova; J. Krasa; L. Laska; K. Mašek; J. Musil; S. Polák; K. Rohlena; J. Schmiedberger; J. Skála; J. Sulek

1988-01-01

154

Novel concept of electric discharge oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A novel concept of discharge oxygen-iodine laser (DOIL) is presented. The supersonic DOIL includes a discharge singlet oxygen generator (DSOG) and discharge atomic iodine generator (DAIG). The operation of DSOG is based on a fast mixing of hybrid argon plasma jet of DC electric arc and RF discharge with a neutral molecular oxygen stream. The goal of our effort is achievement of DOIL oscillations by this new discharge technique, which should provide the singlet oxygen yields exceeding 30% at the total pressures higher than 10 torr. The DAIG operation is based on a cw/pulse RF discharge dissociation of iodine donors directly inside a laser iodine injector. This method substitutes the classic dissociation of molecular iodine by energy of singlet oxygen, which saves its energy for laser generation and so can increase the laser efficiency. The laser power could be thus enhanced by up to 25% if this method is employed in a chemical oxygen-iodine laser (COIL) operation, and even 3 times in DOIL without increase in the iodine laser pumping by singlet oxygen.

Schmiedberger, J.; Jirásek, V.; Kodymová, J.; Rohlena, K.

2009-08-01

155

Iodine laser oscillator in gain switch mode for ns pulses  

Microsoft Academic Search

An iodine laser oscillator is described, which delivers several mJ in ns-pulses. The oscillator is mode-locked by means of an acoustooptical modulator, the pulse duration varies with the iodine pressure. Apparent self-modelocking is due to saturation effects.

K. Hohla; W. Fuss; R. Volk; K.-J. Witte

1975-01-01

156

Chemically pumped iodine laser as a fusion driver  

SciTech Connect

The recently demonstrated chemically pumped iodine laser is evaluated for fusion requirements. Efficiencies greater than 8% and long energy storage times are predicted, with high repetition rates and elimination of pulsed power supplies.

Busch, G.E.

1980-01-01

157

Advances in the RF atomic iodine generator for oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Recent advances in the RF atomic iodine generator for oxygen-iodine lasers are presented. The generator is based on the RF discharge dissociation of a suitable iodine donor immediately before its injection to the flow of singlet oxygen. The discharge is ignited directly in the iodine injector, and the configuration is ready for the laser operation. The dissociation fraction was derived from the atomic iodine number density measured at a presupposed position of laser resonator. The dissociation fraction and the fraction of RF power spent on the dissociation (discharge dissociation efficiency) were measured for the following donors: CH3I, CF3I and HI. A significant improvement of the discharge stability was achieved by increasing the cross-sectional area of the exit injection holes and employing a tangential inlet of working gas into the discharge chamber. The flow rates 0.15 mmol/s and 0.19 mmol/s of produced atomic iodine were achieved using the HI and CF3I, respectively. The atomic iodine number density in the supersonic flow attained 4.22 × 1014 cm-3. The dissociation efficiency was substantially better for HI than for studied organic iodides.

Jirásek, Vít; Schmiedberger, Josef; ?enský, Miroslav; Kodymová, Jarmila

2010-09-01

158

Spatial gain measurements in a chemical oxygen iodine laser (COIL)  

Microsoft Academic Search

The spatial distribution of small signal gain has been investigated on the RADICL device, a supersonic chemical oxygen-iodine laser (COIL). A frequency-stabilized, narrow linewidth diode laser system operating on the F=3?F=4 hyperfine levels of the (2 P1\\/2) to (2P3\\/2) spin-orbit transition in atomic iodine was used as a small signal probe. A peak gain of 1.2%\\/cm was measured along the

R. F. Tate; B. S. Hunt; C. A. Helms; K. A. Kruesdell; G. D. Hager

1995-01-01

159

XeCl laser pumped iodine laser using tC4F9I  

Microsoft Academic Search

An iodine photodissociation laser using t-C4F9I as the active material was pumped by a XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodine pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency

In Heon Hwang; Kwang S. Han; Ja H. Lee

1989-01-01

160

Experimental results on chemical generation of atomic iodine via Cl atoms for chemical oxygen-iodine laser  

Microsoft Academic Search

An alternative chemical way of atomic iodine generation for the chemical oxygen-iodine laser (COIL) was studied. This development was aimed at the laser power increase and simplification of the laser operation control. The method is based on the fast reaction of hydrogen iodide with chemically produced chlorine atoms. Kinetics of the process was studied in two types of the small-scale

Otomar Spalek; Vít Jirásek; Miroslav Censky; Jarmila Kodymová; Ivo Jakubec; Gordon D. Hager

2003-01-01

161

Mixing effects in postdischarge modeling of electric discharge oxygen-iodine laser experiments  

E-print Network

Mixing effects in postdischarge modeling of electric discharge oxygen-iodine laser experiments; accepted 16 May 2006; published online 26 July 2006 In an electric discharge oxygen-iodine laser, laser.1063/1.2215355 I. INTRODUCTION Oxygen-iodine laser systems1 operate on the I 2 P1/2 I 2 P3/2 hereafter denoted I

Carroll, David L.

162

Investigation of the excited state iodine lifetime in the photodissociation of perfluoroalkyl iodides  

NASA Technical Reports Server (NTRS)

An evaluation of prospective laser materials for a space-based solar pumped laser system over the past decade has resulted in the identification of the iodine photodissociation laser as that system best suited to solar-pumped high energy operation. The active medium for the solar-pumped iodine photodissociation laser is from the family of perfluoroalkyl iodides. These lasants have the general form C(n)F(2n + 1)I, often abbreviated as RI. These iodides are known to exhibit photodissociaiton of the C-I bond when irradiated by near UV photons. The focus was on the experimental determination of the lifetime of the excited iodine atom following photodissociation of C4F9I, and also to monitor fluorescence from the iodine molecule at 500 nm to determine if I2 is being produced in the process. Photodissociation is achieved using an XeCl excimer laser with an output wavelength of 308 nm. The XeCl beam is focused into the middle of a cylindrical quartz cell containing the lasant. The laser pulse is detected with a fast risetime photomultiplier tube as it exits the cell. Other aspects of the investigation are discussed.

Cobb, Stephen H.

1991-01-01

163

The asterix III pulsed high-power iodine laser  

Microsoft Academic Search

A system description and first results of the Asterix III high-power iodine laser built at IPP Garching are given. This laser is designed to yield an output energy of 1 kJ in about 1 ns. Until now pulses with output energies up to 300 J and pulse lengths ranging from 1 to 3 ns have been obtained.

G. Brederlow; K. J. Witte; E. Fill; K. Hohla; R. Volk

1976-01-01

164

OPTIMIZING HIGH PRESSURE CHEMICAL OXYGEN-IODINE LASERS  

Microsoft Academic Search

The Blaze II chemical laser model was baselined to existing oxygen-iodine research assessment and device improvement chemical laser (RADICL) gain data. Subsequent Fabry-Perot power calculations with Blaze II were an average of 33% higher than the corresponding stable resonator power data. With the Blaze II model baselined to RADICL gain data, a genetic algorithm (GA) was used to predict optimal

David L. Carroll

1996-01-01

165

Multikilowatt chemical oxygen-iodine laser with chemical generation of molecular iodine  

NASA Astrophysics Data System (ADS)

A multikilowatt chemical oxygen-iodine laser (COIL) using molecular iodine generated chemically as the iodine source was developed and tested. The COIL, with a gain length of 26.5cm, was energized by a square pipe-array jet singlet oxygen generator (JSOG), with a nozzle bank having a designed Mach number of 2.5. The JSOG, operating without a primary buffer gas, has a much better operation stability during basic hydrogen peroxide pumping circulations. Iodine injectors/nozzles made of polyimide were used. An output power of 7.8kW and a chemical efficiency of 24.5% were achieved with a chlorine flow rate of 353mmole/s.

Zhang, Yuelong; Sang, Fengting; Zhang, Peng; Jin, Yuqi; Fang, Benjie; Zhao, Weili; Chen, Fang; Li, Qingwei; Xu, Mingxiu

2007-07-01

166

Studies of new media radiation induced laser  

NASA Technical Reports Server (NTRS)

Various lasants were investigated especially, 2-iodohepafluoropropane (i-C3F7I) for the direct solar pumped lasers. Optical pumping of iodine laser was achieved using a small flashlamp. Using i-C3F7I as a laser gain medium, threshold inversion density, small signal gain, and laser performance at the elevated temperature were measured. The experimental results and analysis are presented. The iodine laser kinetics of the C3F7I and IBr system were numerically simulated. The concept of a direct solar-pumped laser amplifier using (i-C3F7I) as the laser material was evaluated and several kinetic coefficients for i-C3F7I laser system were reexamined. The results are discussed.

Han, K. S.; Shiu, Y. J.; Raju, S. R.; Hwang, I. H.; Tabibi, B.

1984-01-01

167

Detection of iodine-129 by laser-induced fluorescence spectrometry  

Microsoft Academic Search

Isotopically specific fluorescence detection of elemental iodine-129 has been investigated with a broad-band dye laser system. The intracavity spoiling phenomenon was utilized in this investigation to achieve isotopic specificity and to effect a modulated fluorescence signal. This rugged laser-based analytical system was found to exhibit a conventional linear relationship between signal level and analyte concentration, although laser-based instabilities limited detection

Ronald W. Goles; Robert C. Fukuda; Martin W. Cole; Fred P. Brauer

1981-01-01

168

Development of iodine stabilized He?Ne lasers at MRI  

Microsoft Academic Search

Iodine stabilized He?Ne lasers at 633 nm have been developed at the Metrology Research Institute (MRI) for the realization of the definition of the metre. Two stationary lasers (MRI1 and MRI2) present a relative frequency reproducibility of 1.3 × 10?11 during a period of one and a half year. The design of a new portable laser (MRI3) is described. The

J. Hu; T. Ahola; K. Riski; E. Ikonen

1995-01-01

169

Iodine laser production of highly charged Ta ions  

Microsoft Academic Search

The results of systematic studies of multiply charged Ta ion production with the fundamental frequency of an iodine laser (?=1.315µm), and its 2nd (0.657µm) and 3rd (0.438µm) harmonics are summarized and discussed. Short laser pulse (350 ps) and a focus spot diameter of 100µm allowed for the laser power densities in the range of 5×1013–1.5×1015 W\\/cm2. Corpuscular diagnostics were based

L. Láska; J. Krása; K. Masek; M. Pfeifer; B. Králiková; T. Mocek; J. Skála; P. Straka; P. Trenda; K. Rohlena; E. Woryna; J. Farny; P. Parys; J. Wolowski; W. Mróz; A. Shumshurov; B. Sharkov; J. Collier; K. Langbein; H. Haseroth

1996-01-01

170

Chemical oxygen-iodine laser with cryosorption vacuum pump  

NASA Astrophysics Data System (ADS)

In a chemical oxygen-iodine laser (COIL), chemically prepared, gaseous gain medium at 3-10 Torr pressure is drawn through the laser cavity by vacuum suction. Multiple-stage vacuum pumps such as Roots blowers or steam ejectors are typically used to receive and compress the gas flowing from the laser and exhaust it to the atmosphere. The size and weight of such vacuum pumps present a significant challenge to engineering and packaging a transportable COIL system.

Vetrovec, John

2000-05-01

171

Generation and amplification of nanosecond pulses by iodine lasers  

SciTech Connect

Results are reported of experimental investigations of high-power photodissociation iodine laser pumped by lamps and by radiation from high-current electric discharges. The basic parameters of the working medium, the parameters of both lamp-pumped and discharge-pumped lasers, and methods of shaping of a short pulse with diffraction directivity of the radiation are investigated. The possibility of effective amplification of a short pulse by an iodine amplifier pumped with an open high-current discharge is demonstrated. An iodine laser generating a pulse of duration 1 nsec, divergence 10/sup -4/ rad, and energy 100 J at a contrast 10/sup 8/ and 300 J at a contrast 10/sup 2/-10/sup 3/ is described.

Zuev, V.S.; Katulin, V.A.; Nosach, V.Y.; Petrov, A.L.

1982-12-01

172

XeCl laser pumped iodine laser using t-C4F9I  

NASA Technical Reports Server (NTRS)

An iodine photodissociation laser using t-C4F9I as the active material was pumped by a XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodine pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

Hwang, In Heon; Han, Kwang S.; Lee, Ja H.

1989-01-01

173

Frequency stabilization of an external cavity diode laser to molecular iodine at 657.483 nm  

E-print Network

Frequency stabilization of an external cavity diode laser to molecular iodine at 657.483 nm Hui to iodine at 633 nm. Most member states of the Convention du Mètre have adopted such lasers as the national. Frequency stabilization of the external cavity diode laser (ECDL) to the iodine HFS components using

Shy,Jow-Tsong

174

Evolution of the electric discharge oxygen-iodine laser David L. Carrolla  

E-print Network

Evolution of the electric discharge oxygen-iodine laser David L. Carrolla , Gabriel F. Benavidesa and modeling have led to a continuing evolution of the Electric Oxygen-Iodine Laser (ElectricOIL) system. This continuous wave (cw) laser operating on the 1315 nm transition of atomic iodine is pumped by the production

Carroll, David L.

175

Demonstration of an iodine laser pumped by an air-helium electric discharge  

E-print Network

Demonstration of an iodine laser pumped by an air-helium electric discharge B. S. Woodard, J. W and a continuous-wave laser on the 1315 nm transition of atomic iodine using the energy transferred to I(2 P1W in a supersonic flow cavity. Keywords: electric oxygen iodine laser, electric discharge, singlet oxygen, active

Carroll, David L.

176

Recent Electric Oxygen-Iodine Laser Experiments and Modeling David L. Carrolla  

E-print Network

Recent Electric Oxygen-Iodine Laser Experiments and Modeling David L. Carrolla , Gabriel F and modeling have led to a continuing evolution of the Electric Oxygen-Iodine Laser (ElectricOIL) system. A new with BLAZE-V shows that an iodine pre-dissociator can have a dramatic impact upon gain and laser performance

Carroll, David L.

177

Discharge-driven electric oxygen-iodine laser superlinear enhancement via increasing g0L  

E-print Network

Discharge-driven electric oxygen-iodine laser superlinear enhancement via increasing g0L G. F the development of an electric oxygen-iodine laser with higher output using a larger product of gain and gain length, g0L. A factor of 4.4 increase in laser power output on the 1315 nm atomic iodine transition

Carroll, David L.

178

Systematic development of the electric discharge oxygen-iodine laser David L. Carrolla  

E-print Network

1 Systematic development of the electric discharge oxygen-iodine laser David L. Carrolla , Gabriel have led to continued improvements in the hybrid Electric Oxygen-Iodine Laser (ElectricOIL) system. Keywords: hybrid electric discharge oxygen-iodine laser, ElectricOIL, EOIL, DOIL, singlet oxygen 1

Carroll, David L.

179

Development of the electric discharge oxygen-iodine laser David L. Carrolla  

E-print Network

Development of the electric discharge oxygen-iodine laser David L. Carrolla , Joseph T. Verdeyena ABSTRACT In the hybrid electric discharge Oxygen-Iodine laser (ElectricOIL), the desired O2(a1. As the development of this type of iodine laser continues, the roles of oxygen atoms and NO/NO2 are found to be very

Carroll, David L.

180

Spatial and recovery measurements of gain in an electric oxygen-iodine laser  

E-print Network

Spatial and recovery measurements of gain in an electric oxygen- iodine laser G. F. Benavidesa ABSTRACT Recent investigations of an Electric Oxygen-Iodine Laser system have shown that computational oxygen-iodine laser kinetics rates. Understanding of this kinetic process should enable us to accommodate

Carroll, David L.

181

Super-linear Enhancement of the Electric Oxygen-Iodine Laser David L. Carrolla  

E-print Network

Super-linear Enhancement of the Electric Oxygen-Iodine Laser David L. Carrolla , Brian S. Woodardb., Urbana, Illinois, 61801, United States ABSTRACT Continuing experiments with Electric Oxygen-Iodine Laser: electric discharge oxygen-iodine laser, ElectricOIL, EOIL, DOIL, singlet delta oxygen 1. INTRODUCTION

Carroll, David L.

182

Enhancement of electric oxygen-iodine laser performance using a rectangular discharge and longer gain length  

E-print Network

Enhancement of electric oxygen-iodine laser performance using a rectangular discharge and longer of Physics. doi:10.1063/1.3269811 The electrically driven oxygen-iodine laser Electri- cOIL that was first on the demonstration of a 95% enhancement in continuous-wave laser power on the 1315 nm transition of atomic iodine via

Carroll, David L.

183

Iodine stabilization of a diode laser in the optical communication band  

E-print Network

Iodine stabilization of a diode laser in the optical communication band Hsiang-Chen Chui and Sen-harmonic signal of a 197.2-THz 1520.25-nm distributed-feedback diode laser to the absorption lines of the iodine-nm diode laser.10 In 2002, Klein and Arie reported the application of wavelength references to iodine

Shy,Jow-Tsong

184

Enhanced performance of an electric oxygen-iodine laser D. L. Carrolla  

E-print Network

Enhanced performance of an electric oxygen-iodine laser D. L. Carrolla , G. F. Benavidesa,b , J. W and modeling have led to continued enhancements in the Electric Oxygen-Iodine Laser (ElectricOIL) system. This continuous wave (cw) laser operating on the 1315 nm transition of atomic iodine is pumped by the production

Carroll, David L.

185

Experimental Effects of Atomic Oxygen on the Development of an Electric Discharge Oxygen Iodine Laser  

E-print Network

of the electric discharge iodine laser continues, the role of oxygen atoms downstream of the discharge region temperature. Keywords: chemical oxygen-iodine laser, COIL, ElectriCOIL, RF excitation of oxygen, singlet-delta oxygen, DOIL 1.0 INTRODUCTION The classic chemical oxygen-iodine laser (COIL) system1 operates on the I(2

Carroll, David L.

186

Electric Oxygen-Iodine Laser Performance Enhancement using Larger Discharge and Resonator Mode Volumes  

E-print Network

Electric Oxygen-Iodine Laser Performance Enhancement using Larger Discharge and Resonator Mode that significantly higher power was available in the electric oxygen-iodine laser gas flow which could be extracted length of the laser cavity, plus the addition of an iodine pre-dissociator discharge are expected

Carroll, David L.

187

Gain recovery in an electric oxygen-iodine laser J. W. Zimmerman,1,a  

E-print Network

Gain recovery in an electric oxygen-iodine laser J. W. Zimmerman,1,a G. F. Benavides,2 A. D. Palla online 14 January 2009 Recent investigations of an electric oxygen-iodine laser system have shown American Institute of Physics. DOI: 10.1063/1.3064163 The electrically driven oxygen-iodine laser Electri

Carroll, David L.

188

Enhanced performance of an electric oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Experiments and modeling have led to continued enhancements in the Electric Oxygen-Iodine Laser (ElectricOIL) system. This continuous wave (cw) laser operating on the 1315 nm transition of atomic iodine is pumped by the production of O2(a) in a radio-frequency (RF) discharge in an O2/He/NO gas mixture. New discharge geometries have led to improvements in O2(a) production and efficiency. A 95% enhancement in cw laser power was achieved via a 50% increase in gain length, flow rates, and discharge power. A further 87% increase in extracted laser power was obtained using a larger mode volume resonator. The gain has improved by more than 100-fold from the initial demonstration of 0.002% cm-1 to 0.26% cm-1, and similarly the outcoupled laser power has improved more than 500-fold from 0.16 W to 102 W.

Carroll, D. L.; Benavides, G. F.; Zimmerman, J. W.; Woodard, B. S.; Day, M. T.; Palla, A. D.; Verdeyen, J. T.; Solomon, W. C.

2010-02-01

189

Gain and continuous-wave laser power enhancement with a multiple discharge electric oxygen-iodine laser  

E-print Network

Gain and continuous-wave laser power enhancement with a multiple discharge electric oxygen-iodine in an electric oxygen-iodine laser. O2 a 1 is produced by two parallel radio-frequency-excited electric.1063/1.2948860 The electrically driven oxygen-iodine laser Electri- cOIL that was first demonstrated by Carroll et al.1,2 operates

Carroll, David L.

190

Parameters of an electric-discharge generator of iodine atoms for a chemical oxygen-iodine laser  

SciTech Connect

Laser-induced fluorescence is used for measuring the concentration of iodine molecules at the output of an electric-discharge generator of atomic iodine. Methyl iodide CH{sub 3}I is used as the donor of atomic iodine. The fraction of iodine extracted from CH{sub 3}I in the generator is {approx}50%. The optimal operation regimes are found in which 80%-90% of iodine contained in the output flow of the generator was in the atomic state. This fraction decreased during the iodine transport due to recombination and was 20%-30% at the place where iodine was injected into the oxygen flow. The fraction of the discharge power spent for dissociation was {approx}3%. (elements of laser setups)

Azyazov, V N; Vorob'ev, M V; Voronov, A I; Kupryaev, Nikolai V; Mikheev, P A; Ufimtsev, N I [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2009-01-31

191

Research on advanced chemical and discharge oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

Generation of singlet oxygen and atomic iodine for operation of the chemical or discharge oxygen-iodine laser (COIL/DOIL) is described, employing novel methods and device configurations proposed in our laboratory. A centrifugal spray generator of singlet oxygen was developed, based on the conventional reaction between chlorine and basic hydrogen peroxide. Recent results of theoretical and experimental investigation of the generator parameters are presented. A new conception of the discharge generator of singlet oxygen was initiated, based on a combined DC arc jet and RF discharge techniques. Principle of the generator currently developed and constructed is described. A new device configuration was designed for the alternative method of atomic iodine generation using a radiofrequency discharge decomposition of iodine compounds like CH3I or CF3I. Some recent experimental results of this research are also presented.

Kodymová, Jarmila; Jirásek, Vít; Schmiedberger, Josef; Spalek, Otomar; Censký, Miroslav

2009-02-01

192

XeCl laser pumped iodine laser using tC4F9I  

Microsoft Academic Search

An iodine photodissociation laser using t-C4F9I as the active material was pumped by an XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodide pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency

In Heon Hwang; Kwang S. Han

1989-01-01

193

Discharge formation systems for generating atomic iodine in a pulse-periodic oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Generation characteristics of a pulse-periodic oxygen-iodine laser with the electro-discharge production of atomic iodine were compared with inductively stabilised edged or anisotropic- resistive cathodes used for ignition of the volume discharge. The discharge was initiated by the radiation of a barrier discharge from the side of a grid anode. It was found that at equal specific electrical energy depositions to the gas-discharge plasma, the system with the anisotropic-resistive cathode provides a more stable and uniform volume discharge with the possibility of varying the composition and pressure of working mixtures over a wide range and a greater specific extraction of laser energy is observed (up to 2.4 J L-1). At a high pulse repetition rate of laser pulses (50 - 100 Hz) and long duration of the pulse trains (longer than a minute) the surface of anisotropic-resistive cathode became eroded.

Aksinin, V. I.; Antsiferov, S. A.; Velikanov, S. D.; Gerasimov, A. Yu; Gostev, I. V.; Kazantsev, S. Yu; Kalinovskii, V. V.; Konovalov, V. V.; Kononov, I. G.; Mikhalkin, V. N.; Podlesnykh, S. V.; Sevryugin, I. V.; Firsov, K. N.

2014-01-01

194

The chemically pumped iodine laser as a fusion driver  

Microsoft Academic Search

A chemically pumped iodine laser is evaluated for fusion requirements. Efficiencies greater than 8 percent and long energy storage times are predicted, with high repetition rates and elimination of pulsed power supplies. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Keywords (in text query field) Abstract Text Return: Query Results

G. E. Busch

1980-01-01

195

Iodine photodissociation laser with an intracavity space - time light modulator  

SciTech Connect

A scheme of an iodine laser with two different intracavity space - time modulators based on electrooptic PLZT ceramics is experimentally studied. It is shown that lasing can occur in different angular directions with the use of both modulators. The output laser energy is 10 mJ with a pulse duration of 200 {mu}s and a beam divergence of 6.3 Multiplication-Sign 10{sup -4} rad. The laser field of view (5.1 Multiplication-Sign 10{sup -3} rad) consists of a discrete set of 8 Multiplication-Sign 8 directions. (control of laser radiation parameters)

Kachalin, G N; Pevny, S N; Pivkin, A N; Safronov, A S [Russian Federal Nuclear Center 'All-Russian Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod region (Russian Federation)

2012-08-31

196

Laser-initiated iodine radical chemistry in single microdroplets  

NASA Astrophysics Data System (ADS)

Iodine radical reactions in single free-falling microdroplets of iodododecane, initiated using UV laser photolysis, are probed using Raman spectroscopy. Stimulated Raman spectra, with 532 nm laser excitation, are recorded at varying time delays from the UV pulse. I atom recombination reactions lead to I2 that changes the optical properties of the microdroplet ultimately quenching the Raman signal. This quenching is observed over ˜10 ns, which is about the time resolution of the two-laser experiment. Although the kinetics are too rapid to be measured in current laser configuration, it demonstrates that radical kinetics can be followed in single microdroplets.

Vaughn, Bartholomew S.; Tracey, Phillip J.; Trevitt, Adam J.

2012-11-01

197

Flashlamp-pumped iodine laser with an optically thick medium  

Microsoft Academic Search

A procedure is described for numerical calculations of the temporal and radial dependences of the laser radiation power and energy and also of the refractive index for free-oscillation and inversion-storage conditions in the case of a cylindrically symmetric pump source positioned directly in the gaseous active medium. Some results of these calculations as applied to a CF3I iodine photodissociation laser

G. N. Vinokurov; V Yu Zalesski?; P. I. Krepostnov

1980-01-01

198

Broadband OPCPA pumped by ultra-narrowband gaseous iodine laser  

NASA Astrophysics Data System (ADS)

Amplification of femtosecond pulses using an ultra-narrowband gaseous pulse laser was demonstrated for the first time. A single-shot sub-nanosecond iodine photodissociation laser with a bandwidth of 20 pm was used as a driver in an allstage OPCPA. An externally triggerable OPO tuned to laser line of 1315.24 nm was used in the front end of the iodine laser. Frequency tripled beam at 438 nm was used to pump parametric amplifiers, LBO and KDP crystals. The signal pulses from a Ti:sapphire laser at the central wavelength of 800 nm with a bandwidth of 70 nm (FWHM) were stretched from 12.5 fs to 250 ps and amplified by a factor of 2×108. The amplified pulses of typical bandwidth of 50 nm were compressed down to 27 fs. The output power of 0.5 TW was achieved. An optimized amplifier chain and addition of a third nonlinear crystal would enable to generate femtosecond pulses of several terawatts. The broadband pulses at 800 nm central wavelength were amplified in the KDP crystal for the first time, due to the suitable wavelength of the pump pulses. Availability of large aperture KDP crystals promises the generation of petawatt beam at kJ iodine laser facilities.

Novák, O.; Tur?i?ová, H.; Divoký, M.; Smrž, M.; Huynh, J.; Straka, P.

2012-02-01

199

Pulsed chemical oxygen-iodine laser with volume generation of iodine as a model of a high-power supersonic cw laser  

SciTech Connect

In view of the identity of the kinetic processes and of the active-medium parameters of cw and pulsed chemical oxygen-iodine lasers, a repetitively pulsed laser with volume generation of iodine atoms and with a low average output power can be used as a simulator of a high-power cw laser. A comparison is made of experimental results with the parameters of a cw laser predicted by a numerical model. (lasers and amplifiers)

Yuryshev, Nikolai N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

1998-05-31

200

40 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 36, NO. 1, JANUARY 2000 High-Performance Chemical OxygenIodine Laser  

E-print Network

Oxygen­Iodine Laser Using Nitrogen Diluent for Commercial Applications D. L. Carroll, D. M. King, L the principle design change of moving the iodine injectors closer to throat. Index Terms--Chemical lasers, gas lasers, iodine, laser appli- cations, laser materials-processing applications, lasers, nitrogen, oxygen

Carroll, David L.

201

Production of iodine atoms for an oxygen-iodine laser from iodine-containing molecules with the help of atomic oxygen  

SciTech Connect

A new technique is proposed for the production of atomic iodine for a cw oxygen-iodine laser with the use of reactions between iodine donor molecules and oxygen atoms. The CH{sub 3}I, CF{sub 3}I, or I{sub 2} molecules can be used as donors. Oxygen atoms are injected into the reaction region by admixing the flow of partially dissociated oxygen produced in an electric discharge. The use of atomic iodine instead of molecular iodine excludes the consumption of singlet oxygen O{sub 2}({sup 1{Delta}}) for the dissociation of I{sub 2} and quenching of I* by the I{sub 2} molecules. The latter will supposedly allow raising the optimal density of I and accordingly the gain coefficient. Estimates were made of the required degree of dissociation of oxygen employed to obtain iodine atoms at which the above advantages can be realised. (lasers)

Shepelenko, A A; Mikheev, P A [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2003-03-31

202

Flashlamp-pumped iodine laser with an optically thick medium  

SciTech Connect

A procedure is described for numerical calculations of the temporal and radial dependences of the laser radiation power and energy and also of the refractive index for free-oscillation and inversion-storage conditions in the case of a cylindrically symmetric pump source positioned directly in the gaseous active medium. Some results of these calculations as applied to a CF/sub 3/I iodine photodissociation laser are presented. An analysis is made of the dependences of the laser characteristics on the active gas pressure, degree of dilution, flashlamp radius, resonator loss factor, and pump pulse profile and duration.

Vinokurov, G.N.; Zalesskii, V.Y.; Krepostnov, P.I.

1980-05-01

203

Gain recovery in an electric oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Recent investigations of an electric oxygen-iodine laser system have shown that computational modeling overpredicts the experimentally measured power output for similar gain conditions. This discrepancy is potentially due to an unknown reaction that competes with the forward pumping of I(P21/2) by O2(a ?1). Measurements of gain recovery downstream of an operating laser cavity were performed. Modeling of this experiment shows that reducing the forward pumping rate by an effective factor of approximately 4 to simulate a competing mechanism results in the computational modeling matching the experimental gain recovery measurements, and in improved agreement between the measured and modeled laser power extraction.

Zimmerman, J. W.; Benavides, G. F.; Palla, A. D.; Woodard, B. S.; Carroll, D. L.; Verdeyen, J. T.; Solomon, W. C.

2009-01-01

204

Efficient, small scale chemical oxygen-iodine laser  

SciTech Connect

More than 40% extractable power efficiency has been achieved in a transverse flow, small scale, chemically pumped iodine-atom laser. 5 W of cw laser emission at 1315 nm has been obtained via energy transfer from chemically generated O/sub 2/(/sup 1/..delta..) to I atoms in a 10 x 1 cm/sup 2/ rectangular flow duct. Simple construction materials, safely handled chemicals, and a medium size vacuum pump were used for fabricating and operating the laser. The importance of minimizing quenching of excited species by collision with water molecules or with the wall is demonstrated.

Bachar, J.; Rosenwaks, S.

1982-07-01

205

Frequency tuning of a CW atomic iodine laser via the Zeeman effect  

Microsoft Academic Search

A continuously operating, C3F7I photolytic 1.315-?m atomic iodine laser has been used to make the first precise observations of frequency tuning of an atomic iodine laser by means of the Zeeman effect. Application of a uniform magnetic field to the gain region of the photolytic iodine laser causes the laser to operate at different frequencies as a function of the

M. A. Kelly; J. K. McIver; R. F. Shea; G. D. Hager

1991-01-01

206

On a new method for chemical production of iodine atoms in a chemical oxygen-iodine laser  

SciTech Connect

A new method is proposed for generating iodine atoms in a chemical oxygen-iodine laser. The method is based on a branched chain reaction of dissociation of the alkyl iodide CH{sub 3}I in a medium of singlet oxygen and chlorine. (active media)

Andreeva, Tamara L; Kuznetsova, S V; Maslov, A I; Sorokin, Vadim N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2004-11-30

207

Evolution of the electric discharge oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Experiments and modeling have led to a continuing evolution of the Electric Oxygen-Iodine Laser (ElectricOIL) system. This continuous wave (cw) laser operating on the 1315 nm transition of atomic iodine is pumped by the production of O2(a) in a radio-frequency (RF) discharge in an O2/He/NO gas mixture. New discharge geometries have led to improvements in O2(a) production and efficiency. Further, size scaling is presently showing a super-linear growth in performance; a 95% enhancement in cw laser power was achieved via a 50% increase in gain length, flow rates, and discharge power. New gain recovery measurements and modeling downstream of an operating laser cavity are presented in this work for a wider range of flow conditions to help identify previously unidentified kinetic processes. Larger volume resonators that extend further downstream in the flow direction were able to extract more of the excess energy being carried by the O2(a) from the ElectricOIL gain medium; a further 87% increase in extracted laser power was obtained. As understanding of the ElectricOIL system continues to improve, the design of the laser systematically evolves. The gain has improved by more than 100-fold from the initial demonstration of 0.002% cm-1 to 0.26% cm-1, and similarly the outcoupled laser power has increased more than 600-fold from 0.16 W to 109 W.

Carroll, David L.; Benavides, Gabriel F.; Zimmerman, Joseph W.; Woodard, Brian S.; Palla, Andrew D.; Day, Michael T.; Verdeyen, Joseph T.; Solomon, Wayne C.

2010-11-01

208

XeCl laser pumped iodine laser using t-C4F9I  

NASA Technical Reports Server (NTRS)

An iodine photodissociation laser using t-C4F9I as the active material was pumped by an XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodide pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

Hwang, In Heon; Han, Kwang S.

1989-01-01

209

Nuclear-driven flashlamp pumping of the atomic iodine laser  

SciTech Connect

This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with {sup 10}B and {sup 3}He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C{sub 3}F{sub 7}I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation.

Miley, G.H.

1992-03-01

210

Studies of new media radiation induced laser. Final Report, 1 February 1979-30 April 1984  

SciTech Connect

Various lasants were investigated especially, 2-iodohepafluoropropane (i-C3F7I) for the direct solar pumped lasers. Optical pumping of iodine laser was achieved using a small flashlamp. Using i-C3F7I as a laser gain medium, threshold inversion density, small signal gain, and laser performance at the elevated temperature were measured. The experimental results and analysis are presented. The iodine laser kinetics of the C3F7I and IBr system were numerically simulated. The concept of a direct solar-pumped laser amplifier using (i-C3F7I) as the laser material was evaluated and several kinetic coefficients for i-C3F7I laser system were reexamined. The results are discussed.

Han, K.S.; Shiu, Y.J.; Raju, S.R.; Hwang, I.H.; Tabibi, B.

1984-06-01

211

Threshold kinetics of a solar-simulator-pumped iodine laser  

Microsoft Academic Search

A model of the chemical kinetics of the n-C3F7I solar-simulator-pumped iodine laser is utilized to study the major kinetic processes associated with the threshold behavior of this experimental system. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state recombination with

J. W. Wilson; Y. Lee; W. R. Weaver; D. H. Humes; J. H. Lee

1984-01-01

212

A multiwatt all gas-phase iodine laser (AGIL)  

Microsoft Academic Search

The demonstration and characterization of a multiwatt All Gas-phase Iodine Laser (AGIL) are described. A 20-cm subsonic reactor was used to produce NCl(a1Delta) for a series parametric studies of the I*(2P1\\/2) - I(2P3\\/2) small signal gain and extracted power dependence on reactant flow rates and reaction time. A reduction in the flow channel height led to improved performance. The highest

Gerald C. Manke II; Chris B. Cooper; Shiv C. Dass; Timothy J. Madden; Gordon D. Hager

2004-01-01

213

Mode locking of a cw supersonic chemical oxygen iodine laser  

Microsoft Academic Search

This paper presents the results of the first mode locking experiments on a supersonic chemical oxygen iodine laser (COIL). Mode locking has been achieved using an acousto-optic modulator (AOM) and lasing demonstrated on the TEM00 modes with a small intracavity aperture. A dc magnetic field was used to increase the number of axial modes and a peak power of 2.5

S. P. Phipps; Charles A. Helms; Richard J. Copland; Wolfgang G. Rudolph; Keith A. Truesdell; Gordon D. Hager

1997-01-01

214

Excited states in the active media of oxygen - iodine lasers  

SciTech Connect

A review of investigations of kinetic processes in active media oxygen - iodine lasers (OILs) performed in the last decade is presented. The mechanisms of pumping and quenching of electronically and vibrationally excited O{sub 2} and I{sub 2} molecules are considered, and dissociation mechanisms of I{sub 2} in the active medium of the OIL are analysed. The values of kinetic constants of processes proceeding in the active media of OILs are recommended. (review)

Azyazov, V N [Samara Branch of the P.N. Lebedev Physical Institute, Russian Academy of Sciences, Samara (Russian Federation)

2009-11-30

215

Enhancement of electric oxygen-iodine laser performance using larger mode volume resonators  

E-print Network

Enhancement of electric oxygen-iodine laser performance using larger mode volume resonators Brian S.4130, 140.4780, 230.5750. The electrically driven oxygen-iodine laser (Electric- OIL) that was first report on the demonstration of an 87% enhancement in cw laser power on the 1315 nm transition of atomic

Carroll, David L.

216

Highly efficient cw chemical oxygen-iodine laser with transsonic iodine injection and a nitrogen buffer gas  

SciTech Connect

Methods of increasing the efficiency of low-pressure chemical oxygen-iodine lasers (COILs) with transsonic injection of molecular iodine, in which nitrogen is used as a buffer gas, are studied. A two-layer gas-dynamic model is used for a parametric analysis of physicochemical processes occurring in the transsonic iodine injector and in the COIL resonator, including mixing and generation of radiation. The 3D-RANS computer simulation software is used to study the flow structures resulting from an injection of iodine-containing flow into the transsonic zone of the oxygen nozzle. Experiments with a 10-kW modified laser have resulted in a chemical efficiency of 31.5% for a lasing power of 13.5 kW. The results of experimental studies of the cryosorption COIL exhaust system are presented. (lasers)

Boreysho, A S; Barkan, A B; Vasil'ev, D N; Evdokimov, I M; Savin, A V [D. F. Ustinov Voenmekh Baltic State Technical University, Laser Systems Ltd., St. Petersburg (Russian Federation)

2005-06-30

217

LASERS: Compact oxygen-iodine laser with a thermally insulated jet singlet---oxygen generator  

Microsoft Academic Search

A compact oxygen-iodine laser without a water vapour trap and with an uncooled jet singlet---oxygen generator was constructed. A laser output power of 150 W was reached when the oxygen preassure at the exit from the jet generator was 25 Torr. The specific power averaged over the oxygen-generator cross section was 10 W cm-2.

M. V. Zagidullin; V. D. Nikolaev; M. I. Svistun

1994-01-01

218

Iodine  

USGS Publications Warehouse

In descending order, Chile, Japan and the United States have the largest iodine reserves. Chile produces iodine from iodate minerals while Japan and the United States produce it from sodium iodide solutions found in underground iodide solutions. Iodine is also produced from subterranean brines in Azerbaijan, Russia, Turkmenista, Indonesia and Uzbekistan. In 2005, iodine prices increased sharply to US$19 to US$23 then leveled off at US$23 to US$25.

Krukowski, S.T.

2006-01-01

219

Iodine  

MedlinePLUS

... cause lower-than-average IQ in infants and children and decrease adults' ability to work and think clearly. Goiter, an enlarged thyroid gland , is often the first visible sign of iodine deficiency. What are some effects of iodine on health? Scientists are studying iodine to understand how ...

220

Enhanced performance of the iodine monofluoride (491 nm) laser  

SciTech Connect

The impact of substituting HI for CF{sub 3}I as the iodine donor in the discharge-pumped iodine monofluoride (IF) laser at 491 nm ha been investigated. More than an order of magnitude improvement in output pulse energy has been observed, which is attributed to more efficient production of low-lying ({ital v}{prime} {lt} 5) vibrational levels of the IF ({ital D}{prime}) ion pair state. Preliminary evidence indicates that vibrational excitation of HI ({ital X}{sup 1}{Sigma}{sup +}) assists in the relaxation of the {ital D}{prime} state population. The increased net small signal gain of {ital D}{prime} {r arrow} {ital A}{prime}({ital v}{prime} = 0 {r arrow} {ital v}{double prime}) transitions in HI-containing gas mixtures has the effect of intensifying the 491 nm (0,15) bandhead relative to the lower gain transitions.

Knae, K.Y.; Eden, J.G. (Everitt Lab., Univ. of Illinois, Urbana, IL (US))

1990-09-01

221

LASERS: Iodine laser pumped by light from a shock front created by detonating an explosive  

Microsoft Academic Search

The results are presented of investigations, performed in 1965-1966, of a pulsed photodissociation iodine laser utilizing CF3I and C3F7I molecules and pumped by light from a shock front created by detonating an explosive charge. Such lasers were found to possess a unique combination of high output energy and high pulse power. Two types of laser were studied. In one of

V. P. Arzhanov; Boris L. Borovich; V. S. Zuev; V. M. Kazanskii; V. A. Katulin; G. A. Kirillov; S. B. Kormer; Yu V. Kuratov; A. I. Kuryapin; O. Yu Nosach; M. V. Sinitsyn; Yu Yu Stoilov

1992-01-01

222

High-power chemical oxygen-iodine laser welding  

NASA Astrophysics Data System (ADS)

The present paper describes the welding characteristics with a 10 kW class Chemical Oxygen-Iodine Laser (COIL), whose wavelength is 1.32 micrometer. Bead-on-plate welding tests of 304 stainless steel plates were carried out at laser power 8.5 kW and 11 kW. Three different shielding gases (N2, Ar and He) were used through a coaxial conical shape nozzle under the lens. In COIL welding, the interaction between the laser beam and the laser induced plasma is very small because the wavelength of COIL is shorter than that of CO2 laser, so that the laser beam reaches on the workpiece without absorption by the plasma. As the result of the welding tests, the welded bead shapes did not depend on a type of the shielding gas. Radiograph and longitudinal section tests of the welded beads were carried out. When He and Ar gases were used as the shielding gas, there were several porosities. On the other hand, the use of N2 gas made no porosity. The full penetration on 10 mm thick plate was achieved in the high aspect ratio without the welding defects under the condition of laser power 8.5 kW and welding speed 1.5 m/min.

Nakabayashi, Tokuhiro; Muro, Mikio

2000-02-01

223

Molecular Iodine Spectra and Laser Stabilization by Frequency-Doubled 1534 nm Diode Laser Wang-Yau CHENG, Jow-Tsong SHY, Tyson LIN1  

E-print Network

Molecular Iodine Spectra and Laser Stabilization by Frequency-Doubled 1534 nm Diode Laser Wang harmonic radiation of a 1543 nm diode laser, several predicted rovibronic transitions of molecular iodine communications. [DOI: 10.1143/JJAP.44.3055] KEYWORDS: 1550nm, iodine molecule, DWDM, diode laser, optical

Shy,Jow-Tsong

224

A pulsed oxygen - iodine chemical laser excited by a longitudinal electric discharge  

SciTech Connect

The dependence of the energy parameters of an oxygen - iodine chemical laser with a bulk generation of iodine atoms in a longitudinal electric discharge on the length of the discharge gap is studied for various discharge energies and voltages and various working mixture compositions (at constant oxygen and iodine pressures). Analyses of the results suggests that temperature effects account for a twofold decrease in the specific energy yield for the lasing initiated by a longitudinal electric discharge compared to the photolytic initiation. (lasers)

Vagin, Nikolai P; Yuryshev, Nikolai N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2002-07-31

225

Optical saturation and extraction from the chemical oxygen-iodine laser medium  

Microsoft Academic Search

A rate equation model for the loaded gain of a flowing chemical oxygen-iodine laser is described. It includes pumping of the upper laser level by O2(1?), deactivation by water and energy pooling with O2(1?), stimulated emission on the 3?4 transition, hyperfine relaxation (HFR) of the 2P1\\/2 and 2P3\\/2 iodine sublevels, and velocity cross-relaxation (VCR) of the iodine atoms. The solution

D. A. Copeland; A. H. Bauer

1993-01-01

226

Theoretical study of a large-scale chemically pumped pulsed iodine laser amplifier  

Microsoft Academic Search

The feasibility of a 100 kJ class chemically pumped iodine laser amplifier is studied by numerical calculations of the Maxwell-Bloch equations. The idea is based on a chemical iodine pulse laser utilizing a porous-pipe, high-pressure singlet oxygen generator. It is shown that at the high singlet oxygen pressure conditions, the energy transfer reaction from singlet oxygen to ground state iodine

Masamori Endo; K. Kodama; Y. Handa; Taro Uchiyama

1993-01-01

227

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

In any lasing medium the emission wavelength should be chosen where there is little self absorption. As emission and absorption spectra for metallic vapors did not seem available, therefore, estimates were made of these cross sections for sodium vapor as functions of wavelength. Although absolute values were not obtained, information on where the emission wavelength should occur became evident. The method of obtaining quantities proportional to the cross sections versus wavelength is outlined. A further comparison based on alternative expressions for the absorption and emission cross sections over a limited wavelength range is made.

Harries, W. L.; Fong, Z. S.

1984-01-01

228

Efficient chemical oxygen-iodine laser with longitudinal flow of the active medium  

SciTech Connect

A chemical oxygen-iodine laser with fast flow of the active medium along the optic axis was constructed. Lasing with an output power of 186 W and a chemical efficiency in excess of 20% were achieved. (lasers)

Zagidullin, M V; Nikolaev, V D; Svistun, M I; Khvatov, N A [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

1999-02-28

229

HE-pumped iodine laser for plasma and high intensity interactions  

Microsoft Academic Search

The amplifier channel energetics of high power iodine laser pumped by the radiation of shock wave front is treated. Conditions are discussed when super-high light field can be obtained by focusing the phase-conjugation of laser radiation.

G. A. Kirillov; G. G. Kochemasov; S. M. Kulikov; S. N. Pevny; S. A. Sukharev

1996-01-01

230

Mulitwatt all gas-phase iodine laser (AGIL)  

Microsoft Academic Search

The demonstration and characterization of a multi-watt All Gas-phase Iodine Laser (AGIL) are described. A 20-cm subsonic reactor was used to produce NCl(a1Delta) for a series of parametric studies of the I*(2P1\\/2)-I(2P3\\/2) small signal gain and extracted power dependence on reactant flow rates and reaction time. The highest measured gain was 2.5x10-4 cm-1 and the highest power observed was 18

Gerald C. Manke II; Chris B. Cooper; Shiv C. Dass; Timothy J. Madden; Gordon D. Hager

2003-01-01

231

LASERS: Highly efficient supersonic chemical oxygen --- iodine laser with a chlorine flow rate of 10 mmol s-1  

Microsoft Academic Search

An experimental parametric investigation was made of a compact supersonic chemical oxygen --- iodine laser. The output power of the laser was increased by displacing the point where iodine vapour was added to singlet oxygen from the subsonic to the transonic region of gas flow and by cooling of nitrogen. The output power was 200 W for a Mach number

M. V. Zagidullin; V. D. Nikolaev; M. I. Svistun; N. A. Khvatov; N. I. Ufimtsev

1997-01-01

232

Cutting Performance of a Chemical Oxygen-Iodine Laser William P. Latham, James A. Rothenflue, and Charles A. Helms  

E-print Network

Cutting Performance of a Chemical Oxygen-Iodine Laser William P. Latham, James A. Rothenflue. Green Street Urbana,IL 61801 . Abstract Chemical Oxygen-Iodine Laser (COIL) is a member of the class cutting and drilling. Chemical Oxygen- Iodine Laser (COIL) technology has received considerable interest

Carroll, David L.

233

Laser-induced fluorescence as a tool to verify the reproducibility of iodine-based laser standards: a study of 96 iodine cells  

NASA Astrophysics Data System (ADS)

We have validated the laser-induced fluorescence technique to measure the quality of iodine cells whose transitions are used as a reference in laser standards for the realization of the definition of the metre. In this technique, the change in induced fluorescence is measured for different values of iodine pressure in the cell: for an iodine cell contaminated with foreign gases the fluorescence is more sensitive to iodine pressure changes than for a pure one due to collisional quenching of the excited states. We have measured the fluorescence parameter Ko for a total of 96 iodine cells, and for each cell we correlated Ko with the measured absolute frequency when the cell is inserted into laser standards at wavelengths 515 nm, 532 nm and 633 nm. We observed that the distribution of the quality of the produced iodine cells has a large dispersion and we believe that this also significantly affects the frequency distribution of the iodine-based laser standards that are used to realize the definition of the metre.

Zucco, M.; Robertsson, L.; Wallerand, J.-P.

2013-08-01

234

Discharge pumped iodine monofluoride laser: operating parameters and collisional kinetics  

SciTech Connect

Lasing has been observed at five different wavelengths ranging from 472 to 497 nm from discharge pumped iodine monofluoride (IF). At the optimum output coupling 4 mJ was measured in a 30 ns FWHM pulse with a peak power of 140 kW. The merits and deficiencies of both HI and CF/sub 3/I as iodine donors are discussed. Measurements show the small signal gain to be greater than or equal to 1% cm/sup -1/ from approx. 478 to 497 nm, while much of the absorption is due to excited state of He. Limited line tunability is also demonstrated by using an internally mounted Littrow prism. Quenching measurements of the upper and lower laser level show the lower level to be removed more rapidly, thereby avoiding bottlenecking. In addition, the upper level spontaneous emission lifetime is measured to be 17.2 +- 4.0 ns. Finally studies of the formation kinetics of the upper laser level of IF have shown I*(/sup 4/P) atoms to be an immediate precursor, while the F*(/sup 4/P) atoms are unimportant.

Dlabal, M.L.

1981-01-01

235

Power laser beaming and applications in space  

NASA Technical Reports Server (NTRS)

The concept of power-laser beaming in space is described with reference to particular technologies for such systems and their potential applications. A power-beaming system comprises a laser transmitter and receiver, beam-directing optics, and a laser-to-electric power converter, and the system can be used to: (1) extend a lunar rover's excursion range; (2) boost power levels onboard the Space Station Freedom; and (3) to realize laser propulsion. Attention is also given to the potential pump power available from the strongest solar-pumped iodine photodissociation lasers which, when used with a t-C4F9I lasant, is a suitable laser power transmitter.

Lee, Ja H.; Conway, Edmund J.

1991-01-01

236

Kinetic processes in the laser corona heated by a nanosecond iodine laser  

Microsoft Academic Search

The behaviour of plasma electrons in a laser corona generated by focusing the first harmonic (? = 1.315 µm) beam of the nanosecond\\u000a iodine laser Asterix for a power density in the focal spot of 1016 Wcm?2 is studied by solving a 1D Vlasov equation with a small collision term coupled to the Maxwell equations to describe the wave\\u000a propagation

M. Masek; K. Rohlena

2006-01-01

237

Effect of iodine dissociation in an auxiliary discharge on gain in a pulser-sustainer discharge excited oxygen-iodine laser  

Microsoft Academic Search

The paper presents the results of iodine vapour dissociation measurements in a high voltage, nanosecond pulse duration, repetitively pulsed discharge, used as an auxiliary ('side') discharge in an electric discharge excited oxygen-iodine laser. The side discharge, sustained in a high-pressure iodine vapour\\/helium mixture remained stable in the entire range of experimental conditions. Iodine dissociation fraction generated in the side discharge

A. Hicks; J. R. Bruzzese; I. V. Adamovich

2010-01-01

238

High-efficiency operation of chemical oxygen-iodine laser using nitrogen as buffer gas  

Microsoft Academic Search

High-efficiency operation of supersonic chemical oxygen-iodine laser (COIL) with an advanced jet-type singlet oxygen generator using nitrogen as buffer gas was demonstrated. Laser output was remarkably increased when buffer gas was cooled with liquid nitrogen. The effects of buffer gas temperature on the characteristics of the oxygen-iodine laser medium was discussed. A net chemical efficiency of 23.4% was obtained at

M. Endo; S. Nagatomo; S. Takeda; M. V. Zagidullin; V. D. Nikolaev; H. Fujii; F. Wani; D. Sugimoto; K. Sunako; K. Nanri; T. Fujioka

1998-01-01

239

Magnetic modulation of gain in a chemical oxygen-iodine laser  

Microsoft Academic Search

A magnetic modulation of gain in a continuous-wave (CW) chemical oxygen-iodine laser (COIL) is proposed for several regimes of laser generation. The principle of the method proposed is based on a direct magnetic modulation of gain in the active zone of a COIL utilizing the Zeeman effect on the laser transition 2P1\\/2 -2P3\\/2 of iodine atoms. The possible applications of

Josef Schmiedberger; Jarmila Kodymova; Jiri Kovar; Otomar Spalek; Pavel Trenda

1991-01-01

240

Experiment and modeling of a small-scale, supersonic chemical oxygen-iodine laser  

Microsoft Academic Search

We report on detailed experiment and modeling of a small-scale, supersonic chemical oxygen-iodine laser. The laser has a 5 cm long active medium and utilizes a simple sparger-type O2(1?) chemical generator and a medium-size pumping system. A grid nozzle is used for iodine injection and supersonic expansion. 25 W of cw laser emission at 1.315 µm are obtained in the

A. Elior; B. D. Barmashenko; E. Lebiush; S. Rosenwaks

1995-01-01

241

3-ps synchronized multiframe photographic diagnostic for target experiments with the iodine laser  

SciTech Connect

A diagnostic system is described with which we obtain a sequence of six pictures (interferograms or shadowgrams) of the plasma produced by the iodine laser on solid targets. The system consists of a synchronously pumped dye laser amplified in dye cells pumped by an excimer laser. It delivers a pulse with an energy of 500 ..mu..J and a length of 3 ps at a wavelength of 580 nm that is highly synchronous with the iodine pulse.

Maaswinkel, A.G.M.; Sigel, R.; Baumhacker, H.; Brederlow, G.

1984-01-01

242

Two-dimensional gain measurements in a chemical oxygen-iodine laser (COIL) device  

Microsoft Academic Search

The spatial distribution of gain has been investigated on the Research Assessment and Device Improvement Chemical Laser, a supersonic chemical oxygen-iodine laser (COIL). A frequency-stabilized, narrow linewidth diode laser system operating on the F equals 3 yields F equals 4 hyperfine levels of the (2P1\\/2) to (2P3\\/2) spin-orbit transition in atomic iodine was used as a small signal probe. A

R. F. Tate; B. Scott Hunt; Gordon D. Hager; Charles A. Helms; Keith A. Truesdell

1995-01-01

243

Parametric studies on a short pulsed KrF pumped atomic iodine laser  

Microsoft Academic Search

This paper describes parametric studies performed on a short pulsed KrF excimer pumped atomic Iodine laser. Three different approaches were used to determine the gain in the laser cell. The first technique uses a tunable diode laser to directly measure the transient gain. The second method involves measuring the energy extracted from the laser for various outcoupling mirrors and applying

B. S. Hunt

1995-01-01

244

Optimization of an explosively pumped photo-dissociation iodine laser with phase conjugation  

Microsoft Academic Search

Simulations of an explosively pumped two-stage photo-dissociation iodine laser with an SBS mirror at laser aperture 15 cm have shown a good agreement of calculation and experimental data on energy, laser power dynamics, brightness and Strehl number of output radiation. Calculations and experiments show that parasitic reflections of laser radiation from the windows of amplifiers and elements of the optical

Fedor A. Starikov; Yu. V. Dolgopolov; A. M. Dudov; N. N. Gerasimenko; Gennady G. Kochemasov; S. M. Kulikov; S. N. Pevny; A. F. Shkapa; S. P. Smyshlyaev; Stanislav A. Sukharev; L. I. Zykov

2005-01-01

245

Iodine  

MedlinePLUS

... infertility. Iodine deficiency can also lead to an autoimmune disease of the thyroid and may increase the risk ... is LIKELY SAFE for use on the skin. Autoimmune thyroid disease: People with autoimmune thyroid disease may be especially ...

246

Injectant mole-fraction imaging in compressible mixing flows using planar laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A technique is described for imaging the injectant mole-fraction distribution in nonreacting compressible mixing flow fields. Planar fluorescence from iodine, seeded into air, is induced by a broadband argon-ion laser and collected using an intensified charge-injection-device array camera. The technique eliminates the thermodynamic dependence of the iodine fluorescence in the compressible flow field by taking the ratio of two images collected with identical thermodynamic flow conditions but different iodine seeding conditions.

Hartfield, Roy J., Jr.; Abbitt, John D., III; Mcdaniel, James C.

1989-01-01

247

Theoretical study of a new energy extraction scheme of a chemically pumped pulsed iodine laser amplifier  

Microsoft Academic Search

A new energy extraction scheme of a chemically pumped pulsed large-scale iodine laser based on a high-pressure pulsed singlet oxygen generator is proposed. In previous investigations only low-pressure oxygen generators have been considered. Since they require a high iodine density for an efficient amplifier operation, the lifetime of the stored energy is correspondingly small and thus only small-sized iodine amplifiers

M. Endo; K. Kodama; Y. Handa; T. Uchiyama

1993-01-01

248

Oxygen Discharge and Post-Discharge Kinetics Experiments and Modeling for the Electric Oxygen-Iodine Laser System  

E-print Network

a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser kinetics. 1. Introduction The classical chemical oxygen-iodine laser first reported by McDermott et al.1Oxygen Discharge and Post-Discharge Kinetics Experiments and Modeling for the Electric Oxygen-Iodine

Carroll, David L.

249

Threshold kinetics of a solar-simulator-pumped iodine laser  

SciTech Connect

A model of the chemical kinetics of the n-C3F7I solar-simulator-pumped iodine laser is utilized to study the major kinetic processes associated with the threshold behavior of this experimental system. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state recombination with the alkyl radical and quenching by the parent gas control threshold at higher pressures. Treatment of the hyperfine splitting and uncertainty in the pressure broadening are important factors in fixing the threshold level. In spite of scatter in the experimental data caused by instabilities in the simulator high-pressure arc, reasonable agreement is achieved between the model and experiment. Model parameters arrived at are within the uncertainty range of values found in the literature.

Wilson, J.W.; Lee, Y.

1984-02-01

250

Threshold kinetics of a solar-simulator-pumped iodine laser  

NASA Technical Reports Server (NTRS)

A model of the chemical kinetics of the n-C3F7I solar-simulator-pumped iodine laser is utilized to study the major kinetic processes associated with the threshold behavior of this experimental system. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state recombination with the alkyl radical and quenching by the parent gas control threshold at higher pressures. Treatment of the hyperfine splitting and uncertainty in the pressure broadening are important factors in fixing the threshold level. In spite of scatter in the experimental data caused by instabilities in the simulator high-pressure high-pressure arc, reasonable agreement is achieved between the model and experiment. Model parameters arrived at are within the uncertainty range of values found in the literature.

Wilson, J. W.; Lee, Y.; Weaver, W. R.; Humes, D. H.; Lee, J. H.

1984-01-01

251

Lasing performance of a chemical oxygen iodine laser (COIL) with advanced ejector nozzle banks  

Microsoft Academic Search

Experimental lasing results for the Chemical Oxygen Iodine Laser, (COIL), using four different ejector nozzle configurations are presented. These nozzle banks differed in the location of Iodine injection, the area of the oxygen nozzles, and the nozzle contour of the primary driver nitrogen. The aerodynamic choking of the oxygen jets caused by the under expanded primary driver nitrogen resulted in

Nickolay A. Khvatov; Valeri D. Nikolaev; Michael I. Svistun; Marsel V. Zagidullin; Gordon D. Hager

2002-01-01

252

Investigation of laser-induced iodine fluorescence for the measurement of density in compressible flows  

NASA Technical Reports Server (NTRS)

Laser induced fluorescence is an attractive nonintrusive approach for measuring molecular number density in compressible flows although this technique does not produce a signal that is directly related to the number density. Saturation and frequency detuned excitation are explored as means for minimizing the quenching effect using iodine as the molecular system because of its convenient absorption spectrum. Saturation experiments indicate that with available continuous wave laser sources of Gaussian transverse intensity distribution only partial saturation could be achieved in iodine at the pressures of interest in gas dynamics. Using a fluorescence lineshape theory, it is shown that for sufficiently large detuning of a narrow bandwidth laser from a molecular transition, the quenching can be cancelled by collisional broadening over a large range of pressures and temperatures. Experimental data obtained in a Mach 4.3 underexpanded jet of nitrogen seeded with iodine for various single mode argon laser detunings from a strong iodine transition at 5145 A are discussed.

Mcdaniel, J. C., Jr.

1982-01-01

253

LASERS: Iodine laser pumped by light from a shock front created by detonating an explosive  

NASA Astrophysics Data System (ADS)

The results are presented of investigations, performed in 1965-1966, of a pulsed photodissociation iodine laser utilizing CF3I and C3F7I molecules and pumped by light from a shock front created by detonating an explosive charge. Such lasers were found to possess a unique combination of high output energy and high pulse power. Two types of laser were studied. In one of them the active medium was pumped by light from a shock wave in xenon, and in the other a shock wave propagated through a mixture of the active medium and a rare gas. The energy characteristics of the second type of laser were found to be considerably higher than those of the first type. The laser pulse radiation enegy reached ~100 J with an average power of ~15 MW.

Arzhanov, V. P.; Borovich, Boris L.; Zuev, V. S.; Kazanski?, V. M.; Katulin, V. A.; Kirillov, G. A.; Kormer, S. B.; Kuratov, Yu V.; Kuryapin, A. I.; Nosach, O. Yu; Sinitsyn, M. V.; Sto?lov, Yu Yu

1992-02-01

254

Gain and continuous-wave laser power enhancement with a secondary discharge to predissociate molecular iodine in an electric oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of a 50% enhancement in gain and 38% enhancement in continuous-wave laser power on the 1315nm transition of atomic iodine through the addition of a secondary discharge to predissociate the molecular iodine in an electric oxygen-iodine laser. In the primary discharge the O2(a?1) is produced by a radio-frequency-excited electric discharge sustained in an O2-He-NO gas mixture, and I(P1/22) is then pumped using energy transferred from O2(a?1). A gain of 0.10%cm-1 was obtained and the total laser output power was 6.2W.

Benavides, G. F.; Zimmerman, J. W.; Woodard, B. S.; Carroll, D. L.; Verdeyen, J. T.; Field, T. H.; Palla, A. D.; Solomon, W. C.

2008-01-01

255

g... production in flowing ArO2 surface-wave microwave discharges: Possible use for oxygen-iodine laser excitation  

E-print Network

be effectively used for the oxygen-iodine laser excitation. It is demonstrated that at pressures higher than 10 chemical oxygen-iodine laser operates on the electronic transition of the iodine atom at 1315 nm, where.e., the electric discharge oxygen-iodine laser DOIL as demonstrated by Carroll et al.1 Carroll et al. sug- gest

Guerra, Vasco

256

A 12-kW continuous-wave chemical oxygen-iodine laser  

SciTech Connect

A 12-kW continuous-wave chemical oxygen-iodine laser, provided with an original jet-type singlet oxygen generator, is developed and tested. The experimental and numerical techniques applied for the diagnostics and mathematical simulation of processes in the laser active medium are introduced. Some of the calculation and experimental results are presented. (lasers)

Boreysho, A S; Mal'kov, V M; Savin, Aleksandr V; Vasil'ev, D N; Evdokimov, I M; Trilis, A V; Strakhov, S Yu [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2003-04-30

257

Gain measurements on a short pulsed KrF pumped atomic iodine laser  

Microsoft Academic Search

This paper describes gain measurements on a short pulsed KrF excimer pumped atomic iodine laser. Three different approaches were used to determine the gain. The first technique uses a tunable diode laser to directly measure the transient gain. The second method involves measuring the energy extracted from the laser for various outcoupling mirrors and applying the threshold gain condition to

B. Scott Hunt; Jack McIver; Gordon D. Hager

1993-01-01

258

Continuous wave operation of a non-self-sustained electric discharge pumped oxygen-iodine laser  

Microsoft Academic Search

This letter discusses operation of an electric discharge excited oxygen-iodine laser using a high-pressure, non-self-sustained pulser-sustainer discharge. Small signal gain on the 1315 nm iodine atom transition and the laser output power are measured in the M=3 supersonic cavity downstream of the discharge section. In a 15% O2-85% He mixture, at a discharge pressure of 60 torr and discharge power

A. Hicks; Yu. G. Utkin; W. R. Lempert; J. W. Rich; I. V. Adamovich

2006-01-01

259

Continuous wave operation of a non-self-sustained electric discharge pumped oxygen-iodine laser  

Microsoft Academic Search

This letter discusses operation of an electric discharge excited oxygen-iodine laser using a high-pressure, non-self-sustained pulser-sustainer discharge. Small signal gain on the 1315 nm iodine atom transition and the laser output power are measured in the M=3 supersonic cavity downstream of the discharge section. In a 15% O2–85% He mixture, at a discharge pressure of 60 torr and discharge power

A. Hicks; Yu. G. Utkin; W. R. Lempert; J. W. Rich; I. V. Adamovich

2006-01-01

260

Experimental study of population inversion in the shock-pumped iodine laser  

Microsoft Academic Search

Shock wave radiation allows us to pump quite large volumes and, therefore, to obtain iodine laser beams with high energy and power. In particular, previously we carried out experiments on the shock-pumped iodine laser with a beam aperture up to 1.2 m. Radiation energy up to 6 kJ in a single beam with a pulse duration of 3 - 5

S. N. Pevny; V. A. Eroshenko; Stanislav M. Kulikov; Gennadi A. Kirillov; Gennadiy G. Kochemasov; Sergey P. Smyshlyaev; Stanislav A. Sukharev

1993-01-01

261

Mechanism of dark decomposition of iodine donor in the active medium of a pulsed chemical oxygen - iodine laser  

SciTech Connect

A scheme is proposed that describes the dark decomposition of iodide - the donor of iodine - and the relaxation of singlet oxygen in the chlorine-containing active medium of a pulsed chemical oxygen - iodine laser (COIL). For typical compositions of the active media of pulsed COILs utilising CH{sub 3}I molecules as iodine donors, a branching chain reaction of the CH{sub 3}I decomposition accompanied by the efficient dissipation of singlet oxygen is shown to develop even at the stage of filling the active volume. In the active media with CF{sub 3}I as the donor, a similar chain reaction is retarded due to the decay of CF{sub 3} radicals upon recombination with oxygen. The validity of this mechanism is confirmed by a rather good agreement between the results of calculations and the available experimental data. The chain decomposition of alkyliodides accompanied by an avalanche production of iodine atoms represents a new way of efficient chemical production of iodine for a COIL. (active media)

Andreeva, Tamara L; Kuznetsova, S V; Maslov, A I; Sorokin, Vadim N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2002-06-30

262

Efficient operation of a Co : MgF{sub 2} crystal laser pumped by radiation from a pulsed oxygen - iodine laser  

SciTech Connect

Radiation from a chemical oxygen - iodine laser was used for the first time to pump a Co : MgF{sub 2} crystal laser. The attained differential (slope) efficiency of 40%, corresponding to a quantum efficiency of 62%, demonstrated that a Co : MgF{sub 2} crystal can be used for efficient conversion and summation of iodine laser beams. (lasers)

Vagin, Nikolai P; Podmar'kov, Yu P; Frolov, M P; Yuryshev, Nikolai N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Kryukov, P G [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation)

1998-04-30

263

The research of Iodine pool pressure of chemical oxygen-iodine laser in non-equilibrium condition and its automatic control system design  

NASA Astrophysics Data System (ADS)

In the working process of chemical oxy-iodigenne laser(COIL), the change of iodine pool pressure is complicated. As a result, it causes some mis-judgements, such as the damage of heater and the leakage of iodine steam. Further more, when the heater electric circuit is in a single working status, and after the heater switch is on or off, there exists a buffer time for the stabilization of iodine pool pressure, which is a relatively long time, and the minimum buffer pressure exceeds to 19 torr . Of course, it increases the preparing time for steady operation of laser, and reduces the quality of laser beam. In this paper, we study the iodine pool pressure of COIL in non-equilibrium condition, and analyze the mutation and the serious buffer phenomenon of iodine steam pressure. At the same time, we design an automatic control system for iodine pool pressure, which consists of five modules, such as data collection, automatic control, manual control, heater electric circuit, and the setting and display of pressure. This system uses two kinds of heater electric circuits, in this way, the serious buffer phenomenon of iodine pool pressure is effectively avoided. As a result, the maximal buffer pressure reduces to 4 torr, this makes sure that the iodine steam pressure is suitable for the operation of COIL, which produces a good condition for the steady operation of laser system and an excellent laser output.

Zhou, Songqing; Qu, Pubo; Ren, Weiyan

2013-05-01

264

Two Photon Excitation of Molecular Iodine. An Advanced Laser Technique for the Undergraduate Physical Chemistry Lab  

NASA Astrophysics Data System (ADS)

The iodine molecule is routinely studied in the undergraduate physical chemistry lab and provides practical experiments for topics such as chemical kinetics, phase equilibrium, and electronic molecular structure. In an effort to improve and modernize the physical chemistry lab, many of these experiments now incorporate the use of lasers; for instance, a laser can quite easily be used as the light source for iodine emission and fluorescence quenching experiments. To introduce the use of multiple-laser techniques, and to further the study of iodine in the undergraduate teaching lab, we have developed a double resonance method for accessing the ion-pair states of iodine using a relatively inexpensive nitrogen-pumped dye laser. Iodine is pumped to the B state with the dye laser, followed by excitation to the E and f states with a small portion of the nitrogen beam reflected off the parent beam by a quartz window. The strongest emission to the B state occurs from the f state, and progressions of up to 30 vibrational bands are observed. By varying the energy of the dye laser, we are able to pump vibrational levels of the f state from v=0 up to at least v=17. Analysis of our spectra is complicated by the presence of hot bands and by the relatively large bandwidth of our laser. Even so, we are able to adequately assign most spectral bands and their intensities with the aid of Franck-Condon calculations.

Lynch, W. Bryan; Gootee, Megan J.; Chavez, Marc P.

2009-06-01

265

Iodine lasers. (Latest citations from the INSPEC: Information Services for the Physics and Engineering Communities data base). Published Search  

SciTech Connect

The bibliography contains citations concerning the design, development, and analysis of iodine lasers for industrial and research applications. Topics include oxygen-iodine lasers, optical and chemical pumping, pulsed and continuous wave lasers, kinetic modelling, optical harmonic generation, and optical energy storage. (Contains a minimum of 165 citations and includes a subject term index and title list.)

Not Available

1992-10-01

266

Measurements of peak power enhancement and power conservation in magnetically gain-modulated chemical oxygen-iodine laser  

SciTech Connect

The chemical oxygen-iodine laser (COIL) operates in the near infrared region (1.315 [mu]m) on the magnetic dipole transition between the first electronic metastable state and the basic state of atomic iodine. A periodically pulsed regime of the magnetically gain-switched chemical oxygen iodine laser was investigated. The effects of different magnetic field intensity and pulse length on the laser power pulse enhancement and the mean power conservation were studied experimentally.

Schmiedberger, J.; Kodymova, J.; Kokes, A. (Czech Academy of Sciences, Prague (Czechoslovakia). Inst. of Physics); Spalek, O. (Inst. of Inorganic Chemistry, Prague (Czechoslovakia))

1994-10-01

267

Continuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2,,a1  

E-print Network

Continuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2,,a1 of atomic iodine in favor of the I 2 P1/2 state. The laser output power was 220 mW in a stable cavity.1063/1.1883317 The classic chemical oxygen-iodine laser COIL system1 operates on the I 2 P1/2 I 2 P3/2 electronic transi

Carroll, David L.

268

A 10-watt CW photodissociation laser with IODO perfluoro-tert-butane  

NASA Technical Reports Server (NTRS)

NASA has been investigating the feasibility of direct solar-pumped laser systems for power beaming in space. Among the various gas, liquid, and solid laser systems being proposed as candidates for solar-pumped lasers, the iodine photodissociation gas laser has demonstrated its potential for space application. Of immediate attention is the determination of system requirements and the choice of lasants to improve the system efficiency. The development of an efficient iodine laser depends on the availability of a suitable iodide which has favorable laser kinetics, chemically reversibility, and solar energy utilization. Among the various alkyliodide lasants comparatively tested in a long-pulse system, perfluoro- tert-butyl iodide, T-C4F9I, was found to be the best. However, the operating conditions for the laser medium in a continuously pumped and continuous-flow iodine laser differ considerably from those in the pulsed regime. The results of the continuous wave (CW)) laser performance from t-C4F9I are reported. Perfluoro- n-propyl iodide, n-C3F7I is used for comparison because of its universal use in photodissociation iodine lasers.

Tabibi, Bagher; Venable, Demetrius D.

1989-01-01

269

Cutting performance of a chemical oxygen-iodine laser on aerospace and industrial materials William P. Latham, Kip R. Kendrick, James A. Rothenflue  

E-print Network

Cutting performance of a chemical oxygen-iodine laser on aerospace and industrial materials William Lab, 104 5. Wright St., Urbana, Illinois 61801 ABSTRACT A chemical oxygen-iodine laser (COIL) was used:YAG lasers are used for such applications. More recently, the chemical oxygen-iodine laser (COIL) has

Carroll, David L.

270

Absolute frequency stabilization of diode-laser-pumped Nd:YAG lasers to hyperfine transitions in molecular iodine.  

PubMed

Diode-laser-pumped Nd:YAG lasers were frequency stabilized by locking their frequency-doubled output to Doppler-free absorption lines of the (127)I(2) molecule. The successive two-sample deviation of the beat frequency between two independent iodine-stabilized lasers is less than 650 Hz, or 2.3 x 10(-12) of the laser frequency, for averaging times between 24 and 80 s. PMID:19798134

Arie, A; Schiller, S; Gustafson, E K; Byer, R L

1992-09-01

271

Discharge-driven electric oxygen-iodine laser superlinear enhancement via increasing g0L.  

PubMed

The authors report the development of an electric oxygen-iodine laser with higher output using a larger product of gain and gain length, g0L. A factor of 4.4 increase in laser power output on the 1315 nm atomic iodine transition was achieved with a factor of 3 increase in gain length. I(2P1/2) is pumped using energy transferred from O2(a1?) produced by flowing a gas mixture of O2-He-NO through three coaxial geometry radio-frequency discharges. Continuous wave (CW) average total laser power of 481 W was extracted with g0L=0.042. PMID:22555687

Benavides, G F; Zimmerman, J W; Woodard, B S; Day, M T; King, D M; Carroll, D L; Palla, A D; Verdeyen, J T; Solomon, W C

2012-05-01

272

Scattering of light and acoustic disturbances in the atomic iodine laser  

SciTech Connect

An analysis is presented of the medium refractive index gradients and associated acoustic disturbances (ripples) observed in photolytically pumped atomic iodine laser oscillators. Coupled equations representing acoustic waves with a heating source, atomic iodine laser pumping and chemistry and the laser field are derived and used to evaluate the time-dependent growth rate of the instabilities in the oscillator. The theoretical, linearized model is found to be capable of accounting for growing instabilities, and the predicted scale size of the disturbance is in agreement with observations.

Riley, M.E.

1983-07-01

273

Possibility of operation of a chemical oxygen–iodine laser without a cooled trap  

Microsoft Academic Search

A new proposal is made and discussed that it should be possible to operate a chemical oxygen–iodine laser not with the aid of a cooled trap for freezing out water vapor and hydrogen peroxide, but by deep cooling of a chemical generator. This may improve considerably the operating characteristics of such a laser.

M V Zagidullin; Valerii I Igoshin; V A Katulin; N L Kupriyanov

1983-01-01

274

Metrological Properties of the R(127) Line of Iodine Studied by Laser Saturated Absorption  

Microsoft Academic Search

Experiments performed with two 633-nm He-Ne lasers stabilized by 127I2 intracavity saturated absorption are described. In particular, the measurements of the frequency separation between the various iodine hyperfine components accessible with these lasers and evaluation of their pressure broadening, pressure shift, and Zeeman displacement are reported. Finally, the most important factors which limit reproducibility are discussed.

Pierre Cerez; Alain Brillet; Francis Hartmann

1974-01-01

275

HE-pumped iodine laser for plasma and high intensity interactions  

SciTech Connect

The amplifier channel energetics of high power iodine laser pumped by the radiation of shock wave front is treated. Conditions are discussed when super-high light field can be obtained by focusing the phase-conjugation of laser radiation. {copyright} {ital 1996 American Institute of Physics.}

Kirillov, G.A.; Kochemasov, G.G.; Kulikov, S.M.; Pevny, S.N.; Sukharev, S.A. [Russian Federal Nuclear Center (VNIIEF), 607200, Arzamas-16, Nizhni Novgorod Region (Russia)

1996-05-01

276

Efficient operation of a chemically pumped oxygen iodine laser utilizing dilute hydrogen peroxide  

Microsoft Academic Search

A chemically pumped oxygen iodine laser system has been operated employing 35 wt pct H2O2 rather than commonly used 90 wt pct H2O2. Laser power as high as 40 W has been extracted. The maximum overall efficiency of 20.7 percent, which is almost 25 percent higher than the previously reported best data, has been achieved.

S. Yoshida; H. Fujii; T. Sawano; M. Endo; T. Fujioka

1987-01-01

277

Kinetic analyses of energy storage in a chemically pumped iodine laser  

Microsoft Academic Search

A set of 16 kinetic rate equations is numerically integrated to yield energy storage lifetimes in a chemically pumped iodine laser (CPIL) for various experimental parameters. Storage times greater than 3 ms are possible at room temperature, making the CPIL an interesting candidate for a high efficiency pulsed fusion laser. At low temperatures, storage times may even exceed 1 s.

G. E. Busch

1981-01-01

278

High-energy optically pumped iodine laser. I - Kinetics in an optically thick medium  

Microsoft Academic Search

A theoretical description is given of the operation of a high-energy atomic iodine laser pumped by high-intensity broadband radiation, with allowance for nonlinear transport of pump radiation into an optically thick medium. The proposed model determines the temporal and spatial dependences of the various chemical species, gas temperature, pump radiation, and stimulated emission in the laser medium. The model is

J. S. Cohen; O. P. Judd

1984-01-01

279

Review of explosive-driven iodine lasers in the U.S.  

NASA Astrophysics Data System (ADS)

High-explosive charges were used in the early 1980's at Los Alamos National Laboratory to pump high-energy atomic-iodine lasers. Laser outputs at the kilojoule level were measured in a series of experiments. Two techniques were used to convert the high-explosive (HE) energy release to optical radiation for the photolysis of the perfluoroalkyliodide fuel. One technique used strong shockwaves propagating through argon gas and driven by the detonation as an intense optical pump source. The second approach used exploding metal films driven by megampere-level current pulses from explosive-driven magnetic flux compression generators. The optical extraction system for both types of single-pulse lasers was a power oscillator configuration using a stable resonator. The purpose of these experiments was to evaluate the scaling potential of HE-driven lasers for a number of applications including inertial confinement fusion. The HE field experiments were supported by a number of laboratory laser experiments. Exploding wires were used to pump 100-J atomic-iodine lasers (and 20-J molecular iodine lasers). Atomic-iodine lasers were also pumped with exploding metal films. In support of this work, several types of optical pump sources were characterized. These included HE-driven shockwaves in a variety of rare gases, exploding metal wires and films, surface discharges, ablating-wall flashlamps, and xenon flashlamps. Equivalent blackbody temperatures as a function of various parameters were measured for each source using absolutely calibrated photodetectors equipped with optical bandpass filters.

Jones, Randy C.

1995-03-01

280

Performance of a Multistream Injection Chemical OxygenIodine Laser with Starlet Ejectors  

E-print Network

A variant of an ejector-mixing nozzle for a chemical oxygen­iodine laser was experimentally tested that the starlets provide faster mixing. Hot-flow testing demonstrated that the starlet design improved laser performance by 20­30% above the basic cylindrical ejector design. Furthermore, a conical ejector design

Carroll, David L.

281

History of chemical oxygen-iodine laser (COIL) development in the USA  

Microsoft Academic Search

This is an overview of the development of Chemical Oxygen-Iodine Laser (COIL) technology in the United States. Key technical developments will be reviewed, beginning in 1960 and culminating in 1977 with the first COIL lasing demonstration at the Air Force Weapons Laboratory (now the Phillips Laboratory). The discussion will then turn to subsonic laser development, supersonic lasing demonstration and efficiency

Keith A. Truesdell; Charles A. Helms; Gordon D. Hager

1995-01-01

282

Investigations of photodissociation iodine lasers utilizing molecules with bonds between iodine atoms and group V elements. I - Experimental investigation of \\/CF3\\/2AsI iodine laser  

Microsoft Academic Search

The paper reports results of an experimental investigation of the feasibility of producing a photodissociation iodine laser on the basis of (CF3)2AsI. Attention was given to measurements of the absorption spectrum of (CF3)2AsI molecules, the dependence of output energy on pressure in the laser tube, and the dependence of output energy on pump energy (from the xenon flashlamp). Laser action

T. L. Andreeva; G. N. Birich; V. N. Sorokin; I. I. Struk

1976-01-01

283

Temperature measurement in a compressible flow field using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

The thermometric capability of a two-line fluorescence technique using iodine seed molecules in air is investigated analytically and verified experimentally in a known steady compressible flow field. Temperatures ranging from 165 to 295 K were measured in the flowfield using two iodine transitions accessed with a 30-GHz dye-laser scan near 543 nm. The effect of pressure broadening on temperature measurement is evaluated.

Fletcher, D. G.; Mcdaniel, J. C.

1987-01-01

284

Recent Work on the Development of an Electric Discharge Oxygen Iodine Laser  

Microsoft Academic Search

Theoretical studies have indicated that sufficient fractions of O2( 1 ?) may be produced in an electrical discharge that will permit lasing of an electric discharge oxygen-iodine laser (ElectriCOIL) system in conjunction with injection of pre-dissociated iodine. Results of those studies along with more recent experimental results show that electric excitation is a very complicated process that must be investigated

D. L. Carroll; J. T. Verdeyen; D. M. King; B. Woodardb; L. Skorskib; W. C. Solomon

285

Kinetics of saturation of the active medium of an oxygen-iodine laser  

Microsoft Academic Search

The influence of the incident-field intensity and the rate constants of the active-medium processes in an oxygen-iodine laser on the gain for the 2P(1\\/2)-2P(3\\/2) transition of the iodine atom is investigated theoretically, taking the electron energy exchange between I atoms and O2 molecules, the translational relaxation of I atoms, van der Waals mixing of the 2P(3\\/2) sublevels, and mixing of

M. V. Zagidullin; Valerii I. Igoshin; N. L. Kupriianov

1984-01-01

286

Elementary processes in the active medium of an iodine photodissociation laser  

Microsoft Academic Search

A theoretical analysis is made of the elementary processes occurring in the active medium of an iodine photodissociation laser and affecting its emission spectrum. An estimate is obtained of the cross sections of the transitions between the hyperfine structure components within the group 2P3\\/2 and excited 2P1\\/2 states of atomic iodine, which occur because of collisions with various particles in

E A Yukov

1973-01-01

287

Mechanism of pulse discharge production of iodine atoms from CF3I molecules for a chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The pulsed chemical oxygen-iodine laser (COIL) development is aimed at many new applications. Pulsed electric discharge is most effective in turning COIL operation into the pulse mode by instant production of iodine atoms. A numerical model is developed for simulations of the pulsed COIL initiated by an electric discharge. The model comprises a system of kinetic equations for neutral and charged species, electric circuit equation, gas thermal balance equation and the photon balance equation. Reaction rate coefficients for processes involving electrons are found by solving the electron Boltzmann equation, which is re-calculated in a course of computations when plasma parameters changed. The processes accounted for in the Boltzmann equation include excitation and ionization of atoms and molecules, dissociation of molecules, electron attachment processes, electron-ion recombination, electron-electron collisions, second-kind collisions and stepwise excitation of molecules. The last processes are particularly important because of a high singlet oxygen concentration in gas flow from the singlet oxygen chemical generator. Results of numerical simulations are compared with experimental laser pulse waveforms. It is concluded that there is satisfactory agreement between theory and the experiment. The prevailing mechanism of iodine atom formation from the CF3I donor in a very complex kinetic system of the COIL medium under pulse discharge conditions, based on their detailed numerical modelling and by comparing these results both with experimental results of other authors and their own experiments, is established. The dominant iodine atom production mechanism for conditions under study is the electron-impact dissociation of CF3I molecules. It was proved that in the conditions of the experiment the secondary chemical reactions with O atoms play an insignificant role.

Kochetov, I. V.; Napartovich, A. P.; Vagin, N. P.; Yuryshev, N. N.

2009-03-01

288

Iodine laser pumped with light from a shock front produced by explosive charge detonation  

Microsoft Academic Search

The paper presents results of experimental research undertaken during 1965-1966 which concerned a pulsed photodissociation iodine laser using CF3I and C3F7I molecules pumped with light from a shock front produced by explosive charge detonation. These lasers are shown to feature a unique combination of the high energy and the high power of the radiation pulse. Two types of lasers were

V. P. Arzhanov; B. L. Borovich; V. S. Zuev; V. M. Kazanskii; V. A. Katulin; G. A. Kirillov; S. B. Kormer; Iu. V. Kuratov; A. I. Kuriapin; O. Iu. Nosach

1992-01-01

289

Discharge pumped iodine monofluoride laser: Operating parameters and collisional kinetics  

Microsoft Academic Search

Lasing was observed at five different wavelengths ranging from 472 to 497 nm from discharge pumped iodine monofluoride (IF). At the optimum output coupling 4 mJ was measured in a 30 ns FWHM pulse with a peak power of 140 kW. The merits and deficiencies of both HI and CF3I as iodine donors are discussed. Measurements show the small signal

M. L. Dlabal

1981-01-01

290

Multiphoton ionization of iodine atoms and CF 3I molecules by XeCl laser radiation  

NASA Astrophysics Data System (ADS)

We report about effective ionization of iodine atoms and CF3I molecules under the action of intense XeCl laser radiation (308 nm). The only ion fragment resulting from the irradiation of the CF3I molecules is the I+ ion. We have studied the influence of the intensity, spectral composition, and polarization of the laser radiation used on the intensity of the ion signal and the shape of its time-of-flight peak. Based on the analysis of the results obtained, we have suggested the mechanism of this effect. The conclusion drawn is that the ionization of the iodine atoms by the ordinary XeCl laser with a nonselective cavity results from a three- (2 + 1)-photon REMPI process. This process is in turn due to the presence of accidental two-photon resonances between various spectral components of the laser radiation and the corresponding intermediate excited states of the iodine atom. The probability of ionization of the atoms from their ground state I(2P3/2) by the radiation of the ordinary XeCl laser is more than two orders of magnitude higher than the probability of their ionization from the metastable state I*(2P1/2). The ionization of the CF3I molecules by the XeCl laser radiation occurs as a result of a four-photon process involving the preliminary one-photon dissociation of these molecules and the subsequent (2 + 1)-photon REMPI of the resultant neutral iodine atoms.

Lokhman, V. N.; Ogurok, D. D.; Ryabov, E. A.

2008-01-01

291

Gain and continuous-wave laser power enhancement with a multiple discharge electric oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of a 70% enhancement in gain and 98% enhancement in continuous-wave laser power on the 1315nm transition of atomic iodine via an increase in flow rates and pressure using multiple discharges in an electric oxygen-iodine laser. O2(a?1) is produced by two parallel radio-frequency-excited electric discharges sustained in an O2-He-NO gas mixture, a secondary discharge predissociated the molecular iodine, and I(P1/22) is then pumped using energy transferred from O2(a?1). A gain of 0.17%cm-1 was obtained and the total laser output power was 12.3W.

Zimmerman, J. W.; Woodard, B. S.; Benavides, G. F.; Carroll, D. L.; Verdeyen, J. T.; Palla, A. D.; Solomon, W. C.

2008-06-01

292

Continuous-wave laser oscillation in subsonic flow on the 1315 nm atomic iodine transition pumped by electric discharge produced O2,,a 1  

E-print Network

Continuous-wave laser oscillation in subsonic flow on the 1315 nm atomic iodine transition pumped.993% reflective mirrors. © 2006 American Institute of Physics. DOI: 10.1063/1.2346134 Oxygen-iodine laser systems1 into the possibility of a continu- ous flow hybrid electrically powered oxygen-iodine laser ElectricOIL with electric

Carroll, David L.

293

Gain and continuous-wave laser oscillation on the 1315 nm atomic iodine transition pumped by an air-helium electric discharge  

E-print Network

Gain and continuous-wave laser oscillation on the 1315 nm atomic iodine transition pumped by an air American Institute of Physics. DOI: 10.1063/1.2957678 The classical chemical oxygen iodine laser COIL re investigations into an electrically driven oxygen-iodine laser ElectricOIL that was demonstrated by Carroll et al

Carroll, David L.

294

Planar temperature measurement in compressible flows using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A laser-induced iodine fluorescence technique that is suitable for the planar measurement of temperature in cold nonreacting compressible air flows is investigated analytically and demonstrated in a known flow field. The technique is based on the temperature dependence of the broadband fluorescence from iodine excited by the 514-nm line of an argon-ion laser. Temperatures ranging from 165 to 245 K were measured in the calibration flow field. This technique makes complete, spatially resolved surveys of temperature practical in highly three-dimensional, low-temperature compressible flows.

Hartfield, Roy J., Jr.; Hollo, Steven D.; Mcdaniel, James C.

1991-01-01

295

Efficient chemical oxygen-iodine laser powered by a centrifugal bubble singlet oxygen generator  

NASA Astrophysics Data System (ADS)

Efficient production of singlet delta oxygen in a bubble singlet oxygen generator (BSOG) under the influence of centrifugal acceleration, 136g, has been obtained. An output power of 770W with chemical efficiency of 25.6% has been achieved in a small-scale, supersonic chemical oxygen-iodine laser supplied by the centrifugal BSOG. The ratio of the output power to the basic hydrogen peroxide volumetric flow rate was 4.3KJ/liter. Efficient chemical oxygen-iodine laser (COIL) operation with the centrifugal BSOG demonstrates the potential for mobile COIL applications.

Nikolaev, V. D.; Svistun, M. I.; Zagidullin, M. V.; Hager, G. D.

2005-06-01

296

Relative stability of working mixtures of iodine photodissociation lasers in the presence of stimulated enthalpy scattering  

SciTech Connect

A flashlamp-pumped iodine laser was investigated and it was found that the ratios of the experimentally measured depths of dips in the profiles of inhomogeneity waves in various working mixtures were equal to the ratios of the transient values of the gain in the case of the theoretically calculated stimulated enthalpy scattering. These observations were used as the basis of a rapid method for the determination of the relative stability of working mixtures in iodine lasers in the presence of stimulated enthalpy scattering.

Korol'kov, K.S.; Nosach, O.; Orlov, E.P.

1985-01-01

297

Upper state formation kinetics and line tunability of the iodine monofluoride discharge laser  

SciTech Connect

The collisional kinetics of upper state formation for the iodine monofluoride (IF) discharge pumped laser have been studied using tunable dye laser absorption spectroscopy. As for electron- beam excitation, the immediate precursor to IF*(D') is found to be the I*(6s/sup 4/P) species. Energy stored in the F*(/sup 4/P) states, however, is not recovered in the laser's output due to weak F*..-->..I* collisional coupling. Limited tunability of this laser has been demonstrated with a Littrow prism and has resulted in the observation of a new D'..-->..A'laser transition at 467 nm.

Dlabal, M.L.; Eden, J.G.

1982-06-01

298

Determination of iodine in oyster tissue by isotope dilution laser resonance ionization mass spectrometry  

SciTech Connect

The technique of laser resonance ionization mass spectrometry has been combined with isotope dilution analysis to determine iodine in oyster tissue. The long-lived radioisotope, 129I, was used to spike the samples. Samples were equilibrated with the 129I, wet ashed under controlled conditions, and iodine separated by coprecipitation with silver chloride. The analyte was dried as silver ammonium iodide upon a tantalum filament from which iodine was thermally desorbed in the resonance ionization mass spectrometry instrument. A single-color, two-photon resonant plus one-photon ionization scheme was used to form positive iodine ions. Long-lived iodine signals were achieved from 100 ng of iodine. The precision of 127I/129I measurement has been evaluated by replicate determinations of the spike, the spike calibration samples, and the oyster tissue samples and was 1.0%. Measurement precision among samples was 1.9% for the spike calibration and 1.4% for the oyster tissue. The concentration of iodine determined in SRM 1566a, Oyster Tissue, was 4.44 micrograms/g with an estimate of the overall uncertainty for the analysis of +/- 0.12 microgram/g.

Fassett, J.D.; Murphy, T.J. (National Institute of Standards and Technology, Gaithersburg, MD (USA))

1990-02-15

299

Proceedings of the International Conference on Lasers '98, ed. V.J. Corcoran, STS Press, McLean VA, 1999, in press. PERFORMANCE OF A HIGH POWER CHEMICAL OXYGEN-IODINE LASER  

E-print Network

, 1999, in press. PERFORMANCE OF A HIGH POWER CHEMICAL OXYGEN-IODINE LASER USING NITROGEN DILUENT D of moving the iodine injectors closer to throat. 1. Introduction Lasers made their debut for materials, HF/DF and the chemical oxygen-iodine laser (COIL) [2,3]. Of these other laser technologies, COIL

Carroll, David L.

300

Feasibility of an iodine gas laser pumped by concentrated terrestrial solar radiation  

SciTech Connect

The present work demonstrates the feasibility of a t-C{sub 4}F{sub 9}I iodine gas laser pumped by concentrated terrestrial solar radiation. Iodine gas lasers have advantages when compared to solid-state systems. They pump at low concentration ({approximately}100 suns, as compared to 45,000 suns for the most efficient solid-state lasers; Cooke, 1992), and thus do not require expensive, optical-grade concentration systems. The lasant medium (iodine gas) is easily cooled by flowing the lasant medium, while solid-state lasers require complicated cooling apparatus to avoid crystal fracture from thermal gradients. Finally, a gas laser is easily upsized, as the iodine gas will expand to fill any oscillation cavity. Solid-state lasers are limited by the size of the crystal that can be grown and cooled, and the higher efficiency comes at the cost of the very high solar concentration requirements. The iodine gas under consideration has a smaller overlap with the terrestrial solar spectrum than solid state lasers, and therefore has a lower efficiency. However, comparison of relative efficiencies should also include cost estimates of highly specialized optical equipment (such as sapphire CPC`s), cooling requirements (liquid nitrogen baths), and losses due to blockage of the chopper wheel. Such simplistic comparisons as ratio of power out to solar power in are misleading, as they contain the implicit assumption that solar energy must be purchased, as are fossil fuels. In reality, the solar energy is free, and the true expense is the manufacture and degree of sophistication required of the solar radiation reflection system, and the cooling system.

Terry, C.K.; Peterson, J.E.; Goswami, D.Y. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

1996-05-01

301

Self-initiating volume discharge in iodides used for producing atomic iodine in pulsed chemical oxygen - iodine lasers  

SciTech Connect

A volume self-sustained discharge (VSD) in iodides (C{sub 3}H{sub 7}I, C{sub 4}H{sub 9}I) and in their mixtures with SF{sub 6}, N{sub 2}, and O{sub 2} in the presence of small-scale inhomogeneities on the cathode surface is shown to develop in the form of a self-initiating volume discharge (SIVD), i.e., a volume discharge without any preionisation including discharge gaps with a strong edge enhancement of the electric field. Additions of SF{sub 6} or N{sub 2} to the iodides improves the stability and homogeneity of the SIVD, while adding up to 300 % (relative to the partial iodide pressure) of O{sub 2} to these mixtures has only an insignificant effect on the discharge stability. The possibility of SIVD initiation was modelled experimentally in a 1.5-L discharge volume. For the C{sub 4}H{sub 9}I:O{sub 2}:SF{sub 6}=0.083:0.25:0.67 mixture at a pressure of 72 Torr, the specific energy input into the discharge plasma ranged up to 130 J L{sup -1} in this geometry. A conclusion was drawn that the SIVD is promising for the production of atomic iodine in the pulsed and repetitively pulsed operating regimes of a chemical oxygen - iodine laser. (lasers)

Belevtsev, A A [Institute for High Energy Densities, Associated Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation); Kazantsev, S Yu; Saifulin, A V; Firsov, K N [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2003-06-30

302

Numerical study of He/CF3I pulsed discharge used to produce iodine atom in chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The pulsed discharge for producing iodine atoms from the alkyl and perfluoroalky iodides (CH3I, CF3I, etc.) is the most efficient method for achieving the pulse operating mode of a chemical oxygen-iodine laser. In this paper, a one-dimensional fluid model is developed to study the characteristics of pulsed discharge in CF3I-He mixture. By solving continuity equation, momentum equation, Poisson equation, Boltzmann equation, and an electric circuit equation, the temporal evolution of discharge current density and various discharge products, especially the atomic iodine, are investigated. The dependence of iodine atom density on discharge parameters is also studied. The results show that iodine atom density increases with the pulsed width and pulsed voltage amplitude. The mixture ratio of CF3I and helium plays a more significant role in iodine atom production. For a constant voltage amplitude, there exists an optimal mixture ratio under which the maximum iodine atom concentration is achieved. The bigger the applied voltage amplitude is, the higher partial pressure of CF3I is needed to obtain the maximum iodine atom concentration.

Zhang, Jiao; Wang, Yanhui; Duo, Liping; Li, Guofu; Wang, Dezhen

2013-04-01

303

Gain of the active medium of an iodine photodissociation laser in a magnetic field  

Microsoft Academic Search

The influence of a magnetic field on the gain of the active medium of a photodissociation laser oscillator (amplifier) operating under various conditions is studied theoretically allowing for the hyperfine structure of the active transition in the iodine atom. It is shown that an inhomogeneous longitudinal magnetic field always ensures a practically monotonic reduction in the gain and provides the

B. D. Bobrov; V. M. Kiselev; A. S. Grenishin

1977-01-01

304

Theoretical analysis of the performance of an atomic iodine laser amplifier chain  

Microsoft Academic Search

A numerical solution to the Maxwell-Bloch equations describing the pulse evolution in an amplifying or absorbing medium is used to analyze the performance of an atomic iodine laser amplifier chain with output powers close to 2 TW. Pulse compression occurring as a result of saturation, and related aspects such as damage to components, self-focusing, correlations between input and output pulse

T. Uchiyama; K. J. Witte

1982-01-01

305

Quantitative measurement of density and velocity in compressible flows using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A nonintrusive optical technique for the quantitative measurement of molecular density and velocity at a point or in an entire cross-sectional plane of a compressible flowfield is reported. Iodine molecules, seeded into the flowfield reservoir, are excited by a tunable narrow-bandwidth laser and the resulting spatially-resolved fluorescence is collected by a single- or multiple-element detector. A theoretical model for the iodine laser-induced fluorescence process is essential for quantitative measurements and is developed using a rate-equation approach. Density measurements using laser-induced fluorescence are normally complicated by collisional quenching; however, the theory predicts that the off-resonant fluorescent signal is directly proportional to density. Velocity is directly related to the Doppler shift of the iodine absorption line, determined by monitoring the broadband fluorescent signal as the laser is tuned in frequency. Experiments in a steady supersonic flowfield are compared with numerical calculations to demonstrate the accuracy of the approach for density and velocity measurement and the lack of perturbation to the flowfield by the iodine seeding. Extensions of the current approach to density and velocity measurement in lower Mach number flows, to the measurement of pressure and temperature, and to temporally-resolved measurements are discussed.

Mcdaniel, J. C.

1983-01-01

306

High-performance chemical oxygen-iodine laser using nitrogen diluent for commercial applications  

SciTech Connect

A chemical oxygen-iodine laser (COIL), the VertiCOIL device, was transferred from the Air Force Research Laboratory (AFRL) to the University of Illinois at Urbana-Champaign (UIUC) and made operational. The performance of the high-power VertiCOIL laser was measured with nitrogen diluent. New nozzle designs were investigated and implemented to optimize nitrogen performance. Nitrogen diluent chemical efficiencies of 23% were achieved; these are the highest reported chemical efficiencies with room-temperature nitrogen diluent. A long duration, high chemical efficiency test was demonstrated with nitrogen diluent; a chemical efficiency of 18.5% at 30 mmol/s of chlorine was maintained for 45 min. The highest performance was obtained with new iodine injector blocks and a larger throat height. The new iodine injector blocks moved the injectors closer to the throat by 0.7 cm and the throat height was increased from 0.897 to 1.151 cm (0.353 to 0.453 in). The performance enhancements were in qualitative agreement with the system design predictions of the Blaze II chemical laser model. Three-dimensional computational fluid dynamics calculations using the general aerodynamic simulation program code confirmed the principle design change of moving the iodine injectors closer to throat. Several researchers have suggested that COIL has a significant future as an industrial laser and have identified decommissioning and decontamination (D and D) of nuclear facilities as an important market for COIL.

Carroll, D.L.; King, D.M.; Fockler, L.; Stromberg, D.; Solomon, W.C.; Sentman, L.H.; Fisher, C.H.

2000-01-01

307

Test bed for a high throughput supersonic chemical oxygen --- iodine laser  

Microsoft Academic Search

The paper reports the development of a test bed for a chemical oxygen --- iodine laser based on a high throughput jet flow singlet oxygen generator (JSOG). The system provides vertical singlet oxygen extraction followed by horizontal orientation of subsequent subsystems. This design enables the study of flow complexities and engineering aspects of a distributed weight system as an input

Gaurav Singhal; Mainuddin; R. Rajesh; A. K. Varshney; R. K. Dohare; Sanjeev Kumar; V. K. Singh; Ashwani Kumar; Avinash C. Verma; B. S. Arora; M. K. Chaturvedi; R. K. Tyagi; A. L. Dawar

2011-01-01

308

Test bed for a high throughput supersonic chemical oxygen - iodine laser  

Microsoft Academic Search

The paper reports the development of a test bed for a chemical oxygen - iodine laser based on a high throughput jet flow singlet oxygen generator (JSOG). The system provides vertical singlet oxygen extraction followed by horizontal orientation of subsequent subsystems. This design enables the study of flow complexities and engineering aspects of a distributed weight system as an input

Gaurav Singhal; Mainuddin; R Rajesh; A K Varshney; R K Dohare; Sanjeev Kumar; V K Singh; Ashwani Kumar; Avinash C Verma; B S Arora; M K Chaturvedi; R K Tyagi; A L Dawar

2011-01-01

309

Lasing operation of chemical oxygen-iodine laser without water-vapor trap  

SciTech Connect

cw laser action from chemically pumped iodine atoms was achieved without a cold trap to freeze water vapor. An alkaline solution of H/sub 2/O/sub 2/ was circulated in a porous pipe generator, which made it possible to cool the solution externally. A lasing operation time of about 100 s with a constant output power of 5 W was obtained.

Takehisa, K.; Kikuchi, T.; Uchiyama, T.

1988-03-01

310

High-energy optically pumped iodine laser. I. Kinetics in an optically thick medium  

Microsoft Academic Search

The operation of a high-energy atomic iodine laser pumped by high-intensity broadband radiation is described theoretically. Nonlinear transport of pump radiation into an optically thick medium is specifically taken into account. Integrodifferential formulations are made for both planar and cylindrical geometries. The model obtains the temporal and spatial dependences of the various chemical species, gas temperature, pump radiation, and stimulated

James S. Cohen; O. P. Judd

1984-01-01

311

Test bench for studying the outlook for industrial applications of an oxygen-iodine laser  

SciTech Connect

We report the development and tests of a chemical oxygen-iodine laser test bench based on a twisted-aerosol-flow singlet-oxygen generator and a supersonic laser model for studying the outlook for industrial applications of this laser. The maximal output power of the laser is {approx}65 kW (the average power is {approx}50 kW), corresponding to a specific output power of {approx}110 W cm{sup -2}. The maximal chemical efficiency is {approx}34%. (letters)

Adamenkov, A A; Bakshin, V V; Bogachev, A V; Buryak, E V; Vdovkin, L A; Velikanov, S D; Vyskubenko, B A; Garanin, Sergey G; Gorbacheva, E V; Grigorovich, Sergei V; Il'in, S P; Il'kaev, R I; Ilyushin, Yurii N; Kalashnik, A M; Kolobyanin, Yu V; Leonov, M L; Svischev, V V; Troshkin, M V [Russian Federal Nuclear Center 'All-Russian Scientific Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod Region (Russian Federation)

2007-07-31

312

Experimental investigation of internal losses in iodine lasers pumped by ultraviolet radiation from an open high-current discharge  

SciTech Connect

An experimental investigation was made of the internal losses in photodissociation iodine lasers. It was found that refraction losses are the dominant ones, the loss coefficient due to refraction in the laser investigated being (2--6) x 10/sup -4/ cm/sup -1/, while that representing volume absorption of the radiation in the active region was less than 10/sup -4/ cm/sup -1/. The possibilities are discussed for reducing the internal losses in iodine lasers.

Zuev, V.S.; Korol'kov, K.S.; Nosach, O.Y.; Orlov, E.P.

1980-12-01

313

A 633 nm iodine-stabilized diode-laser frequency standard  

Microsoft Academic Search

An extended-cavity diode laser has been stabilized to hyperfine components of the 6-3, P(33) transition of the B-X system of 127I2 at 633 nm, and its performance evaluated by comparison with an iodine-stabilized He-Ne laser. The Allan standard deviation follows a slope of 3.8 × 10-11 ?-1\\/2, reaching a minimum of 1.7 × 10-12 at 500 s, and the reproducibility

C S Edwards; G P Barwood; P Gill; W R C Rowley

1999-01-01

314

Implantation of ions produced by the use of high power iodine laser  

Microsoft Academic Search

The iodine high power Prague Asterix Laser System (PALS), emitting radiation at 438nm wavelength (3rd-harmonic of a fundamental radiation wavelength equal to 1315nm), was employed to irradiate in vacuum different metallic targets (Cu, Ag and Ta). The high energy (up to 230J) short (400ps) laser pulses produce non-equilibrium plasma expanding mainly along the normal to the target surface. Plasma contains

L. Torrisi; S Gammino; A. M Mezzasalma; J Badziak; P Parys; J Wolowski; E Woryna; J Krása; L Láska; M Pfeifer; K Rohlena; F. P Boody

2003-01-01

315

High-performance chemical oxygen-iodine laser using nitrogen diluent for commercial applications  

Microsoft Academic Search

A chemical oxygen-iodine laser (COIL), the VertiCOIL device, was transferred from the Air Force Research Laboratory (AFRL) to the University of Illinois at Urbana-Champaign (UIUC) and made operational. The performance of the high-power VertiCOIL laser was measured with nitrogen diluent. New nozzle designs were investigated and implemented to optimize nitrogen performance. Nitrogen diluent chemical efficiencies of 23% were achieved; these

D. L. Carroll; D. M. King; L. Fockler; D. Stromberg; W. C. Solomon; L. H. Sentman; C. H. Fisher

2000-01-01

316

Chemical oxygen-iodine laser power generation with an off-axis hybrid resonator  

Microsoft Academic Search

A rectangular negative branch off-axis hybrid resonator was coupled to a 10 kW class chemical oxygen-iodine laser. Resonator setup and alignment turned out to be straightforward. The extracted power was 6.6 kW and reached approximately 70% of the power for an optimized stable resonator. The divergence of the emitted laser beam in the unstable direction was lower than two times

Jürgen Handke; Wolfgang O. Schall; Thomas Hall; Frank Duschek; Karin M. Grünewald

2006-01-01

317

Long operating time CW atomic iodine probe laser at 1. 315. mu. m  

Microsoft Academic Search

A photolytically pumped longitudinal flow CW atomic iodine laser at 1.315 ..mu..m with virtually an unlimited operating time and easy operation is reported. Several weeks of continual operation is easily attainable. The prolonged lasing is achieved by employing a passive closed cycle flow system of the CâF-I laser fuel. A high pressure dc Hg arc lamp is used for the

L. A. Schlie; R. D. Rathge

1984-01-01

318

Repetitively pulsed, 70-J photolytic iodine laser with excellent optical and long\\/reliable operation  

Microsoft Academic Search

The performance of a repetitively pulsed, 70 joule, closed cycle 1.3 ?M photolytic atomic iodine laser with excellent beam quality (BQ=1.15) is presented. This BQ was exhibited in the fundamental mode from a M=3.1 confocal unstable resonator at a 0.5 Hz repetition rate. A closed cycle scrubber\\/laser fuel system consisting of a condensative-evaporative section, two Cu wool I2 reactor regions,

L. A. Schlie; R. D. Rathge

1995-01-01

319

Z-pinch photo-pumped pulsed atomic iodine laser. Final report Oct 81-Sep 82  

SciTech Connect

A pulsed atomic iodine laser (CF3I) was designed and constructed using a coaxial xenon flash lamp as a pump source. The flash lamp was operated at low pressure to obtain pulse compression via xenon self-pinch. Electrical and optical diagnostics were performed for various xenon and CF3I pressures. Calorimeter data and burn patterns were obtained for the laser. Time-resolved spectroscopic data were taken throughout the CF3I pump band.

Stone, D.H.; Saunders, D.P.; Clark, M.C.

1984-03-01

320

Efficient operation of a chemically pumped oxygen iodine laser utilizing dilute hydrogen peroxide  

SciTech Connect

A chemically pumped oxygen iodine laser system has been operated employing 35 wt. % H/sub 2/O/sub 2/ rather than commonly used 90 wt. % H/sub 2/O/sub 2/. Laser power as high as 40 W has been extracted. The maimum overall efficiency of 20.7%, which is almost 25% higher than the previously reported best data, has been achieved.

Yoshida, S.; Fujii, H.; Sawano, T.; Endo, M.; Fujioka, T.

1987-11-09

321

Review of explosive-driven iodine lasers in the U.S  

Microsoft Academic Search

High-explosive charges were used in the early 1980's at Los Alamos National Laboratory to pump high-energy atomic-iodine lasers. Laser outputs at the kilojoule level were measured in a series of experiments. Two techniques were used to convert the high-explosive (HE) energy release to optical radiation for the photolysis of the perfluoroalkyliodide fuel. One technique used strong shockwaves propagating through argon

C. R. Jones

1995-01-01

322

Demonstration of a repetitively pulsed magnetically gain-switched chemical oxygen iodine laser  

Microsoft Academic Search

Recently, modulation of the output from a chemical oxygen iodine laser (COIL) has been demonstrated by applying a pulsed magnetic field directly to the laser cavity. A peak-to- average power enhancement of 3.2 was obtained. The rate of change of the magnetic field in these experiments, however, was relatively slow, 0.5 gauss\\/microsecond(s) . In this article, we report the demonstration

Gordon D. Hager; D. Kopf; David N. Plummer; T. Salsich; Peter G. Crowell

1993-01-01

323

Effects of the laser field on an inhomogeneity wave in the active medium of an iodine photodissociation laser  

SciTech Connect

The laser field was found to affect the profile of the refractive index n in an inhomogeneity wave in a flashlamp-pumped iodine photodissociation laser. The laser field produced a dip of depth ..delta..n/sub g/ in the profile of n in the inhomogeneity wave and this increased grad n in the wave by up to an order of magnitude. An analogy was established between the mechanisms of the effect of the laser field on an inhomogeneity wave and the process of stimulated enthalpy scattering. A correlation was found between ..delta..n/sub g/ and the transient gain in stimulated enthalpy scattering in various buffer gases.

Zuev, V.S.; Korol'kov, K.S.; Nosach, O.Y.; Orlov, E.P.

1984-07-01

324

Proceedings of the International Conference on Lasers `95, eds. V.J. Corcoran and T.A. Goldman, STS Press, McLean VA, 1996, pp. 225-231. OPTIMIZING HIGH PRESSURE CHEMICAL OXYGEN-IODINE LASERS  

E-print Network

Press, McLean VA, 1996, pp. 225-231. OPTIMIZING HIGH PRESSURE CHEMICAL OXYGEN-IODINE LASERS David L laser model was baselined to existing oxygen-iodine research assessment and device improvement chemical* by N2. I. Introduction The typical chemical oxygen-iodine laser (COIL) utilizes an energy transfer from

Carroll, David L.

325

Pulsed chemical oxygen - iodine laser initiated by a transverse electric discharge  

SciTech Connect

A pulsed chemical oxygen - iodine laser with a volume production of atomic iodine in a pulsed transverse electric discharge is studied. An increase in the partial oxygen pressure was shown to increase the pulse energy with retention of the pulse duration. At the same time, an increase in the iodide pressure and the discharge energy shortens the pulse duration. Pulses with a duration of 6.5 {mu}s were obtained, which corresponds to a concentration of iodine atoms of 1.8 x 10{sup 15} cm{sup -3}. This concentration is close to the maximum concentration attained in studies of both cw and pulsed oxygen-iodine lasers. A specific energy output of 0.9 J litre{sup -1} and a specific power of 75 kW litre{sup -1} were obtained. The ways of increasing these parameters were indicated. It was found that SF{sub 6} is an efficient buffer gas favouring improvements in the energy pulse parameters. (lasers)

Vagin, Nikolai P; Yuryshev, Nikolai N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2001-02-28

326

Effects of chemical kinetics of the performance of the atomic iodine laser system  

SciTech Connect

Model calculations show that chemical reactions which take place in the active medium of a photolytically pumped iodine laser limit the efficiency with which pump photons are utilized and convert significant amounts of the starting material RI to the unwanted by-products R/sub 2/ and I/sub 2/. Laser- and rf-discharge-based methods for regenerating starting materials from by-products are evaluated experimentally. For economical operation of large iodine laser systems, CF/sub 3/I is presently the best starting material, and a pulsed rf-discharge technique is presently the best one for chemical regeneration. The absorbed energy required to regenerate one CF/sub 3/I molecule using pulsed rf-discharge techniques is 5.8 eV.

Fisk, G.A.; Truby, F.K.

1980-01-01

327

Simultaneous multiple-point velocity measurements using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A technique is demonstrated for measuring velocity at multiple locations in a plane of a gaseous flowfield using Doppler-shifted absorption with fluorescence detection from iodine molecules, excited by a sheet of tunable single-axial-mode argon-ion laser radiation at 514.5 nm. Measurements were made simultaneously at 10,000 points in an iodine-seeded supersonic flow field with a 100 x 100 element photodiode array camera and were found to agree well with a numerical solution for the velocity field. The accuracy with which a component of velocity can be measured is limited, in the current approach, by the iodine linewidth to about 5 m/sec.

Mcdaniel, J. C.; Hiller, B.; Hanson, R. K.

1983-01-01

328

Oxygen-iodine ejector laser with a centrifugal bubbling singlet-oxygen generator  

SciTech Connect

It is shown that if a supersonic oxygen-iodine ejector laser is fed by singlet oxygen from a centrifugal bubbling generator operating at a centrifugal acceleration of {approx}400g, the laser output power achieves a value 1264 W at a chemical efficiency of 24.6% for an alkaline hydrogen peroxide flow rate of 208 cm{sup 3}s{sup -1} and a specific chlorine load of 1.34 mmol s{sup -1} per square centimetre of the bubble layer. (lasers)

Zagidullin, M V; Nikolaev, V D; Svistun, M I; Khvatov, N A [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2005-10-31

329

Calculation of the mixing chamber of an ejector chemical oxygen - iodine laser  

SciTech Connect

Gas parameters are calculated at the outlet of the mixing chamber of an ejector chemical oxygen-iodine laser with a nozzle unit consisting of nozzles of three types, which provides a total pressure of the active medium that substantially exceeds a pressure in the generator of singlet oxygen. This technique of forming the laser active medium substantially facilitates the ejection of the exhaust gas to the atmosphere by using a diffuser and single-stage vacuum systems based on water circulating pumps. (lasers, active media)

Zagidullin, M V; Nikolaev, V D [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2001-06-30

330

Conversion of the 'Iskra-5' iodine laser to second-harmonic operating mode  

SciTech Connect

The conversion of the 'Iskra-5' iodine laser to the regime of fusion target irradiation by second harmonic radiation at 657.5 nm is reported. The laser upgrading enabled obtaining from 12 channels a total second-harmonic energy yield of 2.5 kJ, which corresponds to an output power of 5 TW. The conversion efficiency was equal to {approx}50% in experiments with DKDP crystals with an aperture of 35 cm. A series of 12-channel experiments was conducted involving second-harmonic irradiation of microtargets. (lasers)

Annenkov, V I; Vinogradskiy, L M; Gaidash, V A; Galakhov, I V; Garanin, Sergey G; Zhidkov, N V; Zubkov, A V; Kalipanov, S V; Kargin, V A; Kirillov, G A; Kovalenko, V P; Kochemasov, G G; Kravchenko, A G; Krotov, V A; Lazarchuk, V P; Lapin, S G [Institute of Laser Physics Research, Russian Federal Nuclear Center 'All-Russian Scientific Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod region (Russian Federation); Bespalov, V I; Bredikhin, V I; Ershov, V P; Zil'berberg, V V [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

2005-11-30

331

An all gas-phase iodine laser based on amine chemistry  

NASA Astrophysics Data System (ADS)

Laser action has been demonstrated for the 2P 1/2- 2P 3/2 transition of iodine atom pumped by energy transfer from NCl(a 1?) produced by a set of amine-based, all gas-phase chemical reactions. Continuous-wave laser output of 50 mW with 40% duty factor is obtained from a stable optical resonator consisting of two 99.99% reflective mirrors. The observed laser characteristics are reasonably explained by numerical model calculations.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori; Uchiyama, Taro

2009-07-01

332

An all gas-phase iodine laser based on NCl3 reaction system  

NASA Astrophysics Data System (ADS)

Theoretical and experimental studies of the amine-based all gas-phase iodine laser (AGIL) are conducted. The numerical simulation code is a detailed one-dimensional, multiple-leaky-stream-tubes kinetics code combined with all the known rate equations to date. Using this code, we find that the key reactions to achieve positive gain are the deactivation reaction of excited iodine atoms by chlorine atoms and the self annihilation reactions of NCl(1?). The order of the injection nozzles is crucial to suppress these reactions. Following the calculations, we fabricate a flow reactor apparatus and demonstrate laser action for the 2P1/2-2P3/2 transition of iodine atom pumped by energy transfer from NCl(1?) produced by a set of amine-based, all gas-phase chemical reactions. Continuous-wave laser output of 50 mW with 40% duty factor is obtained from a stable optical resonator consisting of two 99.99% reflective mirrors. The observed laser characteristics are reasonably explained by numerical calculations. To our knowledge, this is the first achievement of amine-based AGIL oscillation.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori; Uchiyama, Taro

2010-02-01

333

Lasic -Cavity-enhanced molecular iodine laser frequency stabilization for space projects  

NASA Astrophysics Data System (ADS)

We present work in progress at SYRTE, APC and ARTEMIS aiming at stabilizing the frequency of a Nd:YAG laser using saturated absorption spectroscopy of molecular iodine 127I2. The novel design of the LASIC project allows for robustness and compacity while achieving high-performance phase noise suppression. The project is a follow-up of the laser stabilization work started at Artemis and continued at APC. The use of a low-finesse bow-tie optical cavity around the iodine absorber, combined with an adapted high-frequency modulation of the laser phase -NICE-OHMS technique-yields shot-noise limited saturated absorption signals with cavity-enhanced signal-to-noise ratios. Residual fractional frequency instability in terms of Allan Std. Deviation is expected below 10-14 @1s integration time and down to 10-15 over several hours. The compact iodine / cavity design, and performance well above LISA requirements make this project an interesting candidate for the space-based Gravitational Waves detector. We discuss the scientific background and outline of this project within the LISA framework, as well as its potential impact on other stringent technical requirements of the LISA project (e.g. U.S.O. clock-stability, arm-length measurements. . . ). We also present other possible applications for space projects involving interferometry, laser ranging or onboard ultrastable oscillators.

Turazza, Oscar; Acef, O.; Auger, G.; Halloin, H.; Duburck, F.; Plagnol, E.; Holleville, D.; Dimarcq, N.; Binetruy, P.; Brillet, A.; Lemonde, P.; Devismes, E.; Prat, P.; Lours, M.; Tuckey, P.; Argence, B.

334

Excitation spectrum of the iodine molecule induced by laser radiation in the 15 780-15 815 cm-1 region  

E-print Network

529 Excitation spectrum of the iodine molecule induced by laser radiation in the 15 780-15 815 cm-1 region : « Complement to the Atlas of the iodine molecule spectrum » S. Gerstenkorn, P. Luc and R. Vetter'absorption de la molécule de l'iode (Editions du C.N.R.S., 1978), le spectre d'excitation induit par laser entre

Paris-Sud XI, Université de

335

Improvement in Suppression of Pulsed Nd:YAG Laser Light With Iodine Absorption Cells for Filtered Rayleigh Scattering Measurements  

NASA Technical Reports Server (NTRS)

Filtered Rayleigh scattering using iodine absorption cells is an effective technique for obtaining density, temperature, and velocity measurements in high speed confined flows. By tuning a single frequency laser to a strong iodine absorption line, stray scattered laser light can be greatly suppressed. For example, the minimum transmission predicted by an iodine absorption model calculation is less than 10(exp -5) at the 18788.44/cm line using a 200 mm absorption cell containing iodine vapor at 0.46 T. Measurements obtained by other researches using a CW Nd:YAG laser agree with the model calculations. However, measurements made by us and by others using Q-switched, injection-seeded, frequency doubled Nd:YAG lasers only show minimum transmission of about 3 x 10(exp -3). This greatly reduces the applicability of the filtered Rayleigh scattering technique using these lasers in experiments having large amounts of stray scattered laser light. The purposes of the present study are to characterize the spectrum of the excess light transmitted by the iodine cell and to make changes to the laser to reduce the transmitted laser light. Transmission data as a function of laser frequency for the iodine absorption line at 18788.44/cm are presented. A planar mirror Fabry-Perot interferometer was used to characterize the frequency spectrum of the light passed through the cell. Measurements taken with the laser tuned to the center of the iodine absorption line show the light transmitted through the iodine cell to have a component with a bandwidth of about 40 GHz. This is probably caused by other modes in the laser that exist in spite of the single frequency injection beam. A second broadband component was also observed, possibly caused by the laser flash lamps or by fluorescence. An intracavity etalon was installed in the laser oscillator cavity to suppress the 40 GHz component. Measurements taken with the etalon tuned to the injection frequency showed a reduction in the transmitted laser light. This improvement allows the iodine cell to block significantly more of the stray laser light in filtered Rayleigh scattering experiments. Examples are given of filtered Rayleigh scattering measurements showing the effect of the etalon on measurements taken in a Mach 3 flow in the NASA Lewis 4 inch by 10 inch supersonic wind tunnel.

Seasholtz, Richard G.; Buggele, Alvin E

1997-01-01

336

Nuclear-driven flashlamp pumping of the atomic iodine laser. Final report  

SciTech Connect

This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with {sup 10}B and {sup 3}He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C{sub 3}F{sub 7}I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation.

Miley, G.H.

1992-03-01

337

A pared-down gas-phase kinetics for the chemical oxygen-iodine laser medium  

NASA Astrophysics Data System (ADS)

Kinetic data obtained in the last decade has resulted in revisions of some mechanisms of excitation and deactivation of excited states in the chemical oxygen-iodine laser (COIL) medium. This review considers new kinetic data and presents analyses of the mechanisms of pumping and quenching of electronically and vibrationally excited states in the oxygen-iodine laser media. An effective three-level model of I2 molecule excitation and relaxation has been developed. The calculated effective rate constants for deactivation of I2(X,11 ? ? ? 24) by O2, N2, He and CO2 are presented. A simplified kinetic package for the COIL active medium is recommended. This model consists of a 30-reaction set with 14 species. The results of calculations utilizing simplified model are in good agreement with the experimental data.

Pichugin, S. Yu.; Heaven, M. C.

2013-11-01

338

Iodine laser pumped with light from a shock front produced by explosive charge detonation  

NASA Astrophysics Data System (ADS)

The paper presents results of experimental research undertaken during 1965-1966 which concerned a pulsed photodissociation iodine laser using CF3I and C3F7I molecules pumped with light from a shock front produced by explosive charge detonation. These lasers are shown to feature a unique combination of the high energy and the high power of the radiation pulse. Two types of lasers were investigated, in one of which the active medium was pumped with light from the shock front in xenon, while in the other the shock wave propagated through a mixture of the active medium with a rare gas. The energy characteristics of the second type of laser substantially surpassed those of the first type of laser.

Arzhanov, V. P.; Borovich, B. L.; Zuev, V. S.; Kazanskii, V. M.; Katulin, V. A.; Kirillov, G. A.; Kormer, S. B.; Kuratov, Iu. V.; Kuriapin, A. I.; Nosach, O. Iu.

1992-02-01

339

Investigation of explosively pumped photodisassociation iodine laser with phase conjugation of super-high quality  

Microsoft Academic Search

A non-steady-state theoretical and mathematical model and a complex of computer codes have been developed for modeling a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjugation (PC) at SBS. The model and the complex of codes taking into account 3D of space consist of two blocks. The first block is devoted to detailed modeling of the SBS

Fedor A. Starikov; Yu. V. Dolgopolov; A. M. Dudov; Natalia N. Gerasimenko; Gennadi A. Kirillov; Gennady G. Kochemasov; Stanislav M. Kulikov; Vladimir K. Ladagin; S. N. Pevny; A. F. Shkapa; Sergey P. Smyshlyaev; Stanislav A. Sukharev; L. I. Zykov

2003-01-01

340

Explosively pumped photodissociation iodine laser with phase conjugation of super-high quality: modeling and experiment  

Microsoft Academic Search

A non-steady-state theoretical and mathematical model and a complex of computer codes have been developed for modeling a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjunction (PC) at SBS. The model and the complex of codes taking into account 3D of space consist of two blocks. The first block is devoted to detailed modeling of the SBS

Fedor A. Starikov; Yu. V. Dolgopolov; A. M. Dudov; Gennadi A. Kirillov; Gennady G. Kochemasov; Stanislav M. Kulikov; Vladimir K. Ladagin; A. N. Manachinsky; S. N. Pevny; A. F. Shkapa; Sergey P. Smyshlyaev; Stanislav A. Sukharev; L. I. Zykov

2003-01-01

341

A compact iodine-stabilized HeNe laser and crossover resonances at 543 nm  

Microsoft Academic Search

We have constructed a compact iodine-stabilized 543 nm HeNe laser using the third-harmonic locking technique. From the signal-to-noise ratio, the noise-limited-stability would be better than 1×10?12 for integration time >1 s. Moreover, several crossover resonances of R(12) 26–0 line are investigated and identified. Two crossover resonances are found adjacent to the hyperfine component a9, the recommended wavelength standard. Instead, we

Wang-Yau Cheng; Jow-Tsong Shy; Tyson Lin

1998-01-01

342

Performance of a high-efficiency 5-cm gain length supersonic chemical oxygen-iodine laser  

Microsoft Academic Search

The Air Force Phillips Laboratory has developed a small-scale supersonic chemical oxygen-iodine laser (COIL) test stand (VertiCOIL) to rapidly evaluate emerging potential technology improvements. VertiCOIL was designed to address issues relevant to military and commercial applications such as long run time, high-efficiency operation, and compact design. VertiCOIL demonstrated an overall chemical efficiency of nearly 27%, one of the highest chemical

Tilghman L. Rittenhouse; Stephen P. Phipps; Charles A. Helms

1999-01-01

343

Experimental study of gain and output coupling characteristics of a CW chemical oxygen-iodine laser  

Microsoft Academic Search

Gain and output coupling characteristics of the CW chemical oxygen-iodine laser (COIL) are determined experimentally by means of varying the output coupling method. Under the conditions that the Cl2 flow rate is 11.8 mmol\\/s, the I2 molar flow rate is from 20 to 50 ?mol\\/s, and the duct pressure is 200 Pa, the following were obtained from the experimental data:

Josef Schmiedberger; Jarmila Kodymova; Otomar Spalek; Jiri Kovar

1991-01-01

344

Efficient chemical oxygen-iodine laser powered by a centrifugal bubble singlet oxygen generator  

Microsoft Academic Search

Efficient production of singlet delta oxygen in a bubble singlet oxygen generator (BSOG) under the influence of centrifugal acceleration, 136 g, has been obtained. An output power of 770 W with chemical efficiency of 25.6% has been achieved in a small-scale, supersonic chemical oxygen-iodine laser supplied by the centrifugal BSOG. The ratio of the output power to the basic hydrogen

V. D. Nikolaev; M. I. Svistun; M. V. Zagidullin; G. D. Hager

2005-01-01

345

Singlet oxygen generator for a solar powered chemically pumped iodine laser. Final Report  

Microsoft Academic Search

The potential of solid phase endoperoxides as a means to produce single-delta oxygen in the gas phase in concentrations useful to chemical oxygen-iodine lasers was investigated. The 1,4 - endoperoxide of ethyl 3- (4-methyl - 1-naphthyl) propanoate was deposited over an indium-oxide layer on a glass plate. Single-delta oxygen was released from the endoperoxide upon heating the organic film by

Busch

1984-01-01

346

REVIEW: Excited states in the active media of oxygen — iodine lasers  

NASA Astrophysics Data System (ADS)

A review of investigations of kinetic processes in active media oxygen — iodine lasers (OILs) performed in the last decade is presented. The mechanisms of pumping and quenching of electronically and vibrationally excited O2 and I2 molecules are considered, and dissociation mechanisms of I2 in the active medium of the OIL are analysed. The values of kinetic constants of processes proceeding in the active media of OILs are recommended.

Azyazov, V. N.

2009-11-01

347

Low-pressure mercury lamp pumped atomic iodine laser of high efficiency  

Microsoft Academic Search

For single pulse operation it was demonstrated that a low-pressure mercury lamp can successfully pump the atomic iodine laser using the active medium CF3I. For a 22 ms long pump pulse an output energy of 100 mJ emitted over the same time duration was obtained. Measured oscillator efficiency was 0.54%. With respect to stored optical energy an efficiency of 1.6%

K. J. Witte; P. Burkhard; H. R. Lüthi

1979-01-01

348

Mode locking of a CW supersonic chemical oxygen-iodine laser  

Microsoft Academic Search

This paper presents the results of the first mode-locking experiments on a supersonic chemical oxygen-iodine laser (COIL). Mode locking has been achieved using an acoustooptic modulator (AOM) and lasing demonstrated on the TEM00 modes with a small intracavity aperture. A dc magnetic field was used to increase the number of axial modes and a peak power of 2.5 kW has

Stephen P. Phipps; Charles A. Helms; R. James Copland; Wolfgang Rudolph; Keith A. Truesdell; Gordon D. Hager

1996-01-01

349

Explosively pumped photo-dissociation iodine laser with phase conjugation  

Microsoft Academic Search

In this paper, we show that spontaneous emission at input signal ?0.1-1 W\\/cm2 does not lead to self-excitation of amplifiers whereas parasitic reflections of laser radiation can be very dangerous. The laser beam brightness and high phase conjugated quality in the focussed beam depends on coefficient R of parasitic diffuse reflections from amplifiers windows and selector lenses. The effective operation

S. Fedor; D. Yuri; D. Aleksandr; G. Natalia; K. Gennadi; K. Stanislav; L. Vladimir; P. Sergei; S. Aleksandr; S. Sergei; S. Stanislav; Z. Leonid

2003-01-01

350

Efficient generation in a chemical oxygen - iodine laser with a low buffer-gas flow rate  

SciTech Connect

The efficient generation in a chemical oxygen - iodine laser (COIL) with a low buffer-gas flow rate for Mach numbers M {<=} 1 is demonstrated. The maximum output power of the COIL was 415 W for a molecular chlorine flow rate of 20 mmol s{sup -1}, which corresponds to a chemical efficiency {eta}{sub ch} =23%. It is shown that the substitution of the buffer gas CO{sub 2} for N{sub 2} does not cause any significant variation in the dependence of the output power on the degree of dilution of the active medium. (lasers)

Azyazov, V N; Safonov, V S; Ufimtsev, N I [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2002-09-30

351

Unstable resonators of high-power chemical oxygen-iodine lasers  

SciTech Connect

Configurations of unstable resonators are considered depending on the basic parameters of a high-power chemical oxygen-iodine laser and the design of an unstable resonator is proposed which provides the compensation of the inhomogeneity of the small-signal gain downstream of the active medium, a high energy efficiency, and stability to intracavity aberrations. The optical scheme of this resonator is presented and its properties are analysed by simulating numerically the kinetics of the active medium and resonator itself in the diffraction approximation. (laser beams and resonators)

Savin, A V; Strakhov, S Yu; Druzhinin, S L [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2006-09-30

352

Active-medium inhomogeneities and optical quality of radiation of supersonic chemical oxygen-iodine lasers  

SciTech Connect

Optical inhomogeneities of the active medium of a supersonic chemical oxygen-iodine laser (COIL) and their effect on the radiation parameters are studied in the case when an unstable resonator is used. Classification of optical inhomogeneities and the main factors affecting the quality of COIL radiation are considered. The results of numerical simulation of a three-dimensional gas-dynamic active medium and an unstable optical resonator in the diffraction approximation are presented. The constraints in the fabrication of large-scale COILs associated with a deterioration of the optical quality of radiation are determined. (lasers)

Boreysho, A S; Druzhinin, S L; Lobachev, V V; Savin, A V; Strakhov, S Yu; Trilis, A V [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2007-09-30

353

Similarity criteria in calculations of the energy characteristics of a cw oxygen - iodine laser  

NASA Astrophysics Data System (ADS)

The calculated and experimental data on the energy efficiency of a cw oxygen - iodine laser (OIL) are analysed based on two similarity criteria, namely, on the ratio of the residence time of the gas mixture in the resonator to the characteristic time of extraction of the energy stored in singlet oxygen td and on the gain-to-loss ratio ?. It is shown that the simplified two-level laser model satisfactorily predicts the output characteristics of OILs with a stable resonator at ?d <= 7. Efficient energy extraction from the OIL active medium is achieved in the case of ?d = 5 - 7, ? = 4 - 8.

Mezhenin, A. V.; Azyazov, V. N.

2012-12-01

354

Enhancement of electric oxygen-iodine laser performance using larger mode volume resonators.  

PubMed

Herein the authors report on the demonstration of an 87% enhancement in cw laser power on the 1315 nm transition of atomic iodine via a 100% increase in the resonator mode volume. O(2)(a1Delta) is produced by a single rf-excited electric discharge sustained in an O(2)-He-NO gas mixture flowing through a rectangular geometry, and I(P2(1/2)) is then pumped using energy transferred from O(2)(a1Delta). A total laser output power of 102.5 W was obtained using a Z-pass resonator configuration. PMID:20479825

Woodard, Brian S; Benavides, Gabriel F; Zimmerman, Joseph W; Carroll, David L; Palla, Andrew D; Day, Michael T; Verdeyen, Joseph T; Solomon, Wayne C

2010-05-15

355

Long operating time CW atomic iodine probe laser at 1. 315. mu. m  

SciTech Connect

A photolytically pumped longitudinal flow CW atomic iodine laser at 1.315 ..mu..m with virtually an unlimited operating time and easy operation is reported. Several weeks of continual operation is easily attainable. The prolonged lasing is achieved by employing a passive closed cycle flow system of the C/sub 3/F-I laser fuel. A high pressure dc Hg arc lamp is used for the photolytic pumping. Peak CW powers of 38 mW have been obtained along with good stability (about 1 percent amplitude fluctuations) in the fundamental TEM/sub 00/ mode via the use of an internal lens.

Schlie, L.A.; Rathge, R.D.

1984-10-01

356

Enhancement of electric oxygen-iodine laser performance using a rectangular discharge and longer gain length  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of a 95% enhancement in continuous-wave laser power on the 1315 nm transition of atomic iodine via a 50% increase in gain length, flow rates, and discharge power. O2(a ?1) is produced by a single radio-frequency-excited electric discharge sustained in an O2-He-NO gas mixture flowing through a rectangular geometry, and I(P21/2) is then pumped using energy transferred from O2(a ?1). A gain of 0.26% cm-1 was obtained and the total laser output power was 54.8 W.

Benavides, G. F.; Zimmerman, J. W.; Woodard, B. S.; Carroll, D. L.; Palla, A. D.; Day, M. T.; Verdeyen, J. T.; Solomon, W. C.

2009-11-01

357

Spatial and recovery measurements of gain in an electric oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Recent investigations of an Electric Oxygen-Iodine Laser system have shown that computational modeling over-predicts the laser power output measured in experiments for similar gain conditions. To help resolve this discrepancy, detailed 2-axis mapping of gain and gain recovery measurements downstream of an operating laser cavity were performed. Modeling and analyses of the gain recovery experiments indicate that when the pumping rate of I(2P1/2) by O2(a1?) is reduced by an effective factor of approximately 4 as a result of an unknown competing reaction, the calculations are well matched to the experimental gain recovery measurements. The agreement between the measured and modeled laser power extraction also significantly improves when the reduced effective pumping rate is used. The results suggest that there may be a competing reaction that effectively reduces the forward pumping rate as compared to the classical chemical oxygen-iodine laser kinetics rates. Understanding of this kinetic process should enable us to accommodate or eliminate its impact on ElectricOIL performance.

Benavides, G. F.; Zimmerman, J. W.; Woodard, B. S.; Palla, A. D.; Carroll, D. L.; Verdeyen, J. T.; Solomon, W. C.

2009-02-01

358

GENETIC ALGORITHMS AND OPTIMIZING CHEMICAL OXYGEN-IODINE LASERS  

Microsoft Academic Search

This paper presents results from the first known application of the genetic algorithm (GA) technique for optimizing the performance of a laser system (chemical, solid-state, or gaseous). The effects of elitism, single point and uniform crossover, creep mutation, different random number seeds, population size, niching and the number of children per pair of parents on the performance of the GA

David L. Carroll

1996-01-01

359

A unified planar measurement technique for compressible flows using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A unified laser-induced fluorescence technique for conducting planar measurements of temperature, pressure and velocity in nonreacting, highly compressible flows has been developed, validated and demonstrated. Planar fluorescence from iodine, seeded into air, was induced by an argon-ion laser and collected using a liquid-nitrogen cooled CCD camera. In the measurement technique, temperature is determined from the fluorescence induced with the laser operated broad band. Pressure and velocity are determined from the shape and position of the fluorescence excitation spectrum which is measured with the laser operated narrow band. The measurement approach described herein provides a means of obtaining accurate, spatially-complete maps of the primary flow field parameters in a wide variety of cold supersonic and transonic flows.

Hartfield, Roy J., Jr.; Hollo, Steven D.; Mcdaniel, James C.

1992-01-01

360

Optimization of an explosively pumped photo-dissociation iodine laser with phase conjugation  

NASA Astrophysics Data System (ADS)

Simulations of an explosively pumped two-stage photo-dissociation iodine laser with an SBS mirror at laser aperture 15 cm have shown a good agreement of calculation and experimental data on energy, laser power dynamics, brightness and Strehl number of output radiation. Calculations and experiments show that parasitic reflections of laser radiation from the windows of amplifiers and elements of the optical scheme are a reason that the brightness value is frequently less than maximum possible one. It is found that the input intensity should exceed 10-20 W/cm2 for eliminating the harmful effect of parasitic reflections on brightness. The brightness increasing is promoted as well by reducing the SBS threshold and displacing the second amplifier towards the SBS mirror at retaining a total length of the system. Under optimal conditions the maximal brightness reaches 1012 J/sr.

Starikov, Fedor A.; Dolgopolov, Yu. V.; Dudov, A. M.; Gerasimenko, N. N.; Kochemasov, Gennady G.; Kulikov, S. M.; Pevny, S. N.; Shkapa, A. F.; Smyshlyaev, S. P.; Sukharev, Stanislav A.; Zykov, L. I.

2005-03-01

361

Test bed for a high throughput supersonic chemical oxygen - iodine laser  

SciTech Connect

The paper reports the development of a test bed for a chemical oxygen - iodine laser based on a high throughput jet flow singlet oxygen generator (JSOG). The system provides vertical singlet oxygen extraction followed by horizontal orientation of subsequent subsystems. This design enables the study of flow complexities and engineering aspects of a distributed weight system as an input for mobile and other platform-mounted systems developed for large scale power levels. The system under consideration is modular and consists of twin SOGs, plenum and supersonic nozzle modules, with the active medium produced in the laser cavity. The maximal chlorine flow rate for the laser is {approx}1.5 mole s{sup -1} achieving a typical chemical efficiency of about 18%. (lasers)

Singhal, Gaurav; Mainuddin; Rajesh, R; Varshney, A K; Dohare, R K; Kumar, Sanjeev; Singh, V K; Kumar, Ashwani; Verma, Avinash C; Arora, B S; Chaturvedi, M K; Tyagi, R K; Dawar, A L

2011-05-31

362

Observation of Pumping Reaction in an Amine-Based All Gas-Phase Iodine Laser Medium  

NASA Astrophysics Data System (ADS)

Gain measurement of all gas-phase iodine laser (AGIL) based on amine-based reactions is conducted. Three gaseous species, namely, NCl3, H, and HI are mixed in a glass tube, in which injection ports of each species are optimized using a numerical simulation code developed in our laboratory. The laser duct is attached downstream to the mixing tube, and a probe beam of 1315 nm passes at 23 cm downstream from the mixing point of H and HI. Hydrogen atoms are produced by the microwave discharge of the H2/He admixture. When NCl3 is not supplied, absorption by the 2P1/2-2P3/2 transition of iodine atoms is observed. When NCl3 is supplied, the absorption dip occasionally turns to the hump, which means that the energy transition from NCl(a1?) to iodine atoms results in population inversion. The observed small signal gain is 0.005%/cm. However, the reproducibility of the observed phenomenon is poor and presumably, some uncontrolled factor affects the gain evolution. To our knowledge, this is the first observation of a positive gain of the amine-based AGIL system.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori; Uchiyama, Taro

2009-03-01

363

Influence of gasdynamic shock waves on the lasing kinetics in a flashlamp-pumped iodine photodissociation laser  

Microsoft Academic Search

An experimental study was conducted on a flashlamp-pumped iodine photodissociation laser to investigate the effect of gasdynamic waves in the active medium on the lasing characteristics. The laser had a working aperture of 20 cm and an active medium 1 m long. The pump source was a straight xenon flashlamp mounted along the cell axis and separated from the active

B. D. Bobrov; V. M. Kiselev; A. S. Grenishin

1983-01-01

364

DEVELOPMENT OF ADVANCED PHOTOLYTIC IODINE LASER (PIL) CUTTING AND JOINING TECHNOLOGIES FOR MANUFACTURING  

SciTech Connect

An evaluation was made of the Photolytic Iodine Laser (PIL) being developed by Advanced Optical Equipment and Services Corporation for metalworking applications. This laser operates in the infrared region of the spectrum and was anticipated to have a very small focal spot size and very low divergence. With these properties, it would be very effective at making small welds and narrow slots in metals. The program was of limited success due to low power output from the laser as well as power and positional instability. Some narrow slots were made and evaluated. The PIL may have applications in the electronics industry, even at low power, if the instability in the beam power and position can be solved.

MUSTALESKI, T.; RICHEY, M

1998-09-01

365

Test bed for a high throughput supersonic chemical oxygen — iodine laser  

NASA Astrophysics Data System (ADS)

The paper reports the development of a test bed for a chemical oxygen — iodine laser based on a high throughput jet flow singlet oxygen generator (JSOG). The system provides vertical singlet oxygen extraction followed by horizontal orientation of subsequent subsystems. This design enables the study of flow complexities and engineering aspects of a distributed weight system as an input for mobile and other platform-mounted systems developed for large scale power levels. The system under consideration is modular and consists of twin SOGs, plenum and supersonic nozzle modules, with the active medium produced in the laser cavity. The maximal chlorine flow rate for the laser is ~1.5 mole s-1 achieving a typical chemical efficiency of about 18%.

Singhal, Gaurav; Mainuddin; Rajesh, R.; Varshney, A. K.; Dohare, R. K.; Kumar, Sanjeev; Singh, V. K.; Kumar, Ashwani; Verma, Avinash C.; Arora, B. S.; Chaturvedi, M. K.; Tyagi, R. K.; Dawar, A. L.

2011-05-01

366

Parametric study of the gain in a small scale, grid nozzle, supersonic chemical oxygen-iodine laser  

Microsoft Academic Search

We report on experiments and model calculations of the small-signal gain and the gain profile in a grid nozzle supersonic chemical oxygen-iodine laser. The laser has a 5-cm long active medium and the gain is measured using a diode laser. The calculations are based on a simple one-dimensional semiempirical model previously developed in our laboratory. The gain is studied as

E. Lebiush; B. D. Barmashenko; A. Elior; S. Rosenwaks

1995-01-01

367

Output mode spectra, comparative parametric operation, quenching, photolytic reversibility, and short-pulse generation in atomic iodine photodissociation lasers  

Microsoft Academic Search

The advantages and disadvantages of the atomic iodine photodissociation laser for high-energy operation have been considered. Laser excitation by both slow and fast flashlamps has been investigated; in slow flash excitation, self-mode-locking occurs frequently and the output-mode characteristics of the laser operated in this way have been studied. The comparative performance of different parent materials for photodissociation has been investigated

C. C. Davis; R. J. Pirkle; R. A. McFarlane; G. J. Wolga

1976-01-01

368

Quantitative characterization of a nonreacting, supersonic combustor flowfield using unified, laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A calibrated, nonintrusive optical technique, laser-induced iodine fluorescence (LIIF) was used to quantify the steady, compressible flowfield of a nonreacting, supersonic combustor. The combustor was configured with single and staged, transverse-air injection into a supersonic-air freestream behind a rearward-facing step. Pressure, temperature, two-velocity components, and injectant mole fraction were measured with high spatial resolution in the three-dimensional flowfields. These experimental results provide a benchmark set of data for validation of computational fluid dynamic (CFD) codes being developed to model supersonic combustor flowfields.

Fletcher, D. G.; Mcdaniel, J. C.

1989-01-01

369

Analytic study of the chain dark decomposition reaction of iodides — atomic iodine donors — in the active medium of a pulsed chemical oxygen—iodine laser: 1. Criteria for the development of the branching chain dark decomposition reaction of iodides  

Microsoft Academic Search

The scheme of chemical processes proceeding in the active medium of a pulsed chemical oxygen—iodine laser (COIL) is analysed. Based on the analysis performed, the complete system of differential equations corresponding to this scheme is replaced by a simplified system of equations describing in dimensionless variables the chain dark decomposition of iodides — atomic iodine donors, in the COIL active

Tamara L Andreeva; S V Kuznetsova; Aleksandr I Maslov; Vadim N Sorokin

2009-01-01

370

ACTIVE MEDIA: Analytic study of the chain dark decomposition reaction of iodides --- atomic iodine donors --- in the active medium of a pulsed chemical oxygen---iodine laser: 2. Limiting parameters of the branching chain dark decomposition reaction of iodides  

Microsoft Academic Search

The final stages in the development of a branching chain decomposition reaction of iodide in the active medium of a pulsed chemical oxygen---iodine laser (COIL) are analysed. Approximate expressions are derived to calculate the limiting parameters of the chain reaction: the final degree of iodide decomposition, the maximum concentration of excited iodine atoms, the time of its achievement, and concentrations

Tamara L. Andreeva; S. V. Kuznetsova; Aleksandr I. Maslov; Vadim N. Sorokin

2009-01-01

371

Analytic study of the chain dark decomposition reaction of iodides — atomic iodine donors — in the active medium of a pulsed chemical oxygen—iodine laser: 2. Limiting parameters of the branching chain dark decomposition reaction of iodides  

Microsoft Academic Search

The final stages in the development of a branching chain decomposition reaction of iodide in the active medium of a pulsed chemical oxygen—iodine laser (COIL) are analysed. Approximate expressions are derived to calculate the limiting parameters of the chain reaction: the final degree of iodide decomposition, the maximum concentration of excited iodine atoms, the time of its achievement, and concentrations

Tamara L Andreeva; S V Kuznetsova; Aleksandr I Maslov; Vadim N Sorokin

2009-01-01

372

JOURNAL DE PHYSIQUE ColZoque C9, suppZe'ment au nO1l, Tome 41, novembre 1980, page C9-449 A POTENTIAL ATOMIC IODINE LASER PUMPED BY ELECTRICALLY GENERATED 'A OXYGEN  

E-print Network

-449 A POTENTIAL ATOMIC IODINE LASER PUMPED BY ELECTRICALLY GENERATED 'A OXYGEN G. Fournier, J. Bonnet and D temperature. The usual atomic iodine laser However, that efficiency in ordinary dis- I 2 ~ 1 2+ I 2 ~ 3 / 2at that an atomic iodine laser than the value for self-sustained oper- can be continuously pumped with a chemical

Paris-Sud XI, Université de

373

Continuous wave optically pumped iodine monofluoride B /sup 3/Pi(0/sup +/). -->. X /sup 1/. sigma. /sup +/ laser  

SciTech Connect

A continuous wave optically pumped iodine monofluoride laser operating on the B /sup 3/Pi(0/sup +/) ..-->.. X /sup 1/..sigma../sup +/ system is described. The laser operated on a series of rovibronic lines originating from v' = 2--5. By tuning the dye laser pump source over a single rovibronic line, spectral structure was produced on the IF laser output that was analyzed and found to be consistent with hyperfine structure in IF. Hyperfine coupling constants were determined in this analysis. Implications for a chemically pumped IF laser are also presented.

Davis, S.J.; Hanko, L.; Wolf, P.J.

1985-06-01

374

Enhancement of the efficiency and control of emission parameters of an unstable-resonator chemical oxygen-iodine laser  

SciTech Connect

The outlook is considered for the development of a high-power supersonic flowing chemical oxygen-iodine laser operating as an amplifier and controlled by radiation from a master oscillator by using an unstable resonator with a hole-coupled mirror. The influence of the seed radiation intensity, the coupling-hole diameter, the active-medium length, and the magnification factor on the parameters of laser radiation is analysed. It is shown that the use of such resonators is most advisable in medium-power oxygen-iodine lasers for which classical unstable resonators are inefficient because of their low magnification factors. The use of unstable resonators with a hole-coupled mirror and injection provides the control of radiation parameters and a considerable increase in the output power and brightness of laser radiation. (control of laser radiation parameters)

Boreisho, A S; Lobachev, V V; Savin, A V; Strakhov, S Yu; Trilis, A V [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2007-07-31

375

Demonstration of an iodine laser pumped by an air-helium electric discharge  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of gain and a continuous-wave laser on the 1315 nm transition of atomic iodine using the energy transferred to I(2P1/2) from O2(a1?) produced by both radio-frequency and microwave electric discharges sustained in a dry air-He-NO gas mixture. Active oxygen and nitrogen species were observed downstream of the discharge region. Downstream of the discharge, cold gas injection was employed to raise the gas density and lower the temperature of the continuous gas flow. Gain of 0.0062 %/cm was obtained and the laser output power was 32 mW in a supersonic flow cavity.

Woodard, B. S.; Zimmerman, J. W.; Benavides, G. F.; Carroll, D. L.; Verdeyen, J. T.; Palla, A. D.; Field, T. H.; Solomon, W. C.; Lee, S.; Rawlins, W. T.; Davis, S. J.

2009-02-01

376

Demonstration of an iodine laser pumped by an air-helium electric discharge  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of gain and a continuous-wave laser on the 1315 nm transition of atomic iodine using the energy transferred to I(2P1/2) from O2(a 1?) produced by both radio-frequency and microwave electric discharges sustained in a dry air-He-NO gas mixture. Active oxygen and nitrogen species were observed downstream of the discharge region. Downstream of the discharge, cold gas injection was employed to raise the gas density and lower the temperature of the continuous gas flow. Gain of 0.0062% cm-1 was obtained and the laser output power was 32 mW in a supersonic flow cavity.

Woodard, B. S.; Zimmerman, J. W.; Benavides, G. F.; Carroll, D. L.; Verdeyen, J. T.; Palla, A. D.; Field, T. H.; Solomon, W. C.; Lee, S.; Rawlins, W. T.; Davis, S. J.

2010-01-01

377

Comparison of 127I II-stabilized frequency-doubled Nd:YAG lasers and evaluation of frequency shifts caused by iodine cells  

NASA Astrophysics Data System (ADS)

We present results of measurement of purity of a set of iodine cells made at our institute. The purity was tested by improved method based on measurement of induced fluorescence and evaluation by the Stern-Volmer formula. The reproducibility of the fluorescence detection system was improved by introducing of additional compensation for the pumping laser spectral and power instabilities. Frequency-doubled Nd:YAG lasers stabilized with these cells were compared to evaluate their frequency shifts. The absolute frequencies of selected iodine hyperfine transitions were measured in direct laser frequency comparison with the reproducibility well below the kHz level. The results indicating the iodine cell purity are presented with relation to the absolute frequency shifts. This not only highlights the influence of iodine cell quality onto the stability and absolute frequency of laser etalons but also shows the way towards improvements of the iodine cell manufacturing technology.

Hrabina, Jan; Jedli?ka, Petr; ?íp, Ond?ej; Lazar, Josef

2008-04-01

378

Focal spot analysis of optical inhomogeneities appearing in the working medium of an iodine photodissociation laser with flashlamp pumping  

NASA Astrophysics Data System (ADS)

We report on the results of experimental studies of optical inhomogeneities appearing in the working medium of an iodine photodissociation laser operating in the inversion accumulation mode and in the free-running mode. The dynamics of evolution of optical inhomogeneities in the free-running mode is studied experimentally.

Kachalin, G. N.; Pivkin, D. N.; Polozov, A. A.; Safronov, A. S.; Khudikov, N. M.

2013-01-01

379

High-energy optically pumped iodine laser. I. Kinetics in an optically thick medium  

SciTech Connect

The operation of a high-energy atomic iodine laser pumped by high-intensity broadband radiation is described theoretically. Nonlinear transport of pump radiation into an optically thick medium is specifically taken into account. Integrodifferential formulations are made for both planar and cylindrical geometries. The model obtains the temporal and spatial dependences of the various chemical species, gas temperature, pump radiation, and stimulated emission in the laser medium. For an active gas of n-C/sub 3/F/sub 7/I, relevant temperature-dependent rate constants, absorption cross sections, and line-broadening coefficients were selected after a critical review of the literature. The model is used to interpret recent laser experiments performed in the nonlinear regime using an intense (approx.22 000 K) flash lamp to pump a n-C/sub 3/F/sub 7/I medium with and without buffer gas. The theoretical results are in excellent agreement with the experimental measurements. The relative importance of the various kinetic processes is evaluated, and the spatial and temporal dependence in the optically thick medium is exhibited. Heating of the medium leads to major changes in the lasing kinetics. It is also observed that a gas-dynamic perturbation wave from the flash-lamp surface significantly limits laser output in some cases. Under some conditions this source drives a pyrolysis wave into the medium, but it is not strong enough to drive a faster photolysis wave.

Cohen, J.S.; Judd, O.P.

1984-04-01

380

Investigation of explosively pumped photo-dissociation iodine laser with phase conjugation of super-high quality  

Microsoft Academic Search

Summary form only given results of simulations and experiments on a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjugation (PC) are presented. Laser system consists of master oscillator, two exploding amplifiers at working mixture 25 Torr C3F7I+125 Torr Xe and amplifier aperture 15 cm, and SBS mirror. SBS mirror consists of an angular selector of Stokes radiation,

F. A. Starikov; Yu. V. Dolgopolov; A. M. Dudov; N. N. Gerasimenko; G. A. Kirillov; G. G. Kochemasov; S. M. Kulikov; V. K. Ladagin; S. N. Pevny; A. F. Shkapa; S. P. Smyshlyaev; S. A. Sukharev; L. I. Zykov

2003-01-01

381

Investigation of an explosively pumped photo-dissociation iodine laser with phase conjugation of super-high quality  

Microsoft Academic Search

Results of simulations and experiments on a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjugation (PC) are presented. The laser system consists of a master oscillator, two exploding amplifiers with a working mixture 25 Torr C3F7I+125 Torr Xe and amplifier aperture of 15 cm, and an SBS-mirror. The SBS mirror consists of an angular selector of Stokes

Fedor A. Starikov; Yu. V. Dolgopolov; A. M. Dudov; Natalia N. Gerasimenko; Gennadi A. Kirillov; Gennady G. Kochemasov; A. V. Kopalkin; S. A. Kovaldov; Stanislav M. Kulikov; Vladimir K. Ladagin; S. N. Pevny; A. F. Shkapa; Sergey P. Smyshlyaev; Stanislav A. Sukharev; L. I. Zykov

2004-01-01

382

Small-signal gain and saturation parameter of a transverse-flow CW oxygen-iodine laser  

Microsoft Academic Search

The small-signal gain and saturation parameter of a transverse-flow CW oxygen-iodine laser have been experimentally obtained for the first time from output power measurements made as a function of the cavity losses without using a CW probe laser. These measurements typically yield a small-signal gain of 0.045 per m and a saturation parameter of 0.44 kW\\/sq cm for a Cl2

K. Watanabe; S. Kashiwabara; K. Sawai; S. Toshima; R. Fujimoto

1983-01-01

383

O2-I laser (Oxygen-iodine) mixing studies using LIF (Laser Induced Fluorescence)  

Microsoft Academic Search

Laser Induced Fluorescence (LIF) was incorporated to study the degree of mixing in two subsonic nozzle variations for the O2-I laser system. The studies were performed using a testbed version of COIL-IV, an O2-I laser. I2 was injected through the nozzles and excited with an Ar laser to produce fluorescence. The observed jet trajectories could then be compared to trajectories

Y. D. Jones; D. Plummer; L. D. Watkins; G. D. Hager

1987-01-01

384

Catalytic enhancement of singlet oxygen for hybrid electric discharge oxygen-iodine laser systems  

NASA Astrophysics Data System (ADS)

We are investigating catalytically enhanced production of singlet oxygen, O2(a1?g), observed by reaction of O2/He discharge effluents on an iodine oxide film surface in a microwave discharge-flow reactor at 320 K. We have previously reported a two-fold increase in the O2(a) yields by this process, and corresponding enhancement of I(2P1/2) excitation and small-signal gain upon injection of I2. In this paper we report further observations of the effects of elevated temperature up to 410 K, and correlations of the catalytically generated O2(a) with atomic oxygen over a large range of discharge-flow conditions. We have applied a diffusion-limited reaction rate model to extrapolate the catalytic reaction rates to the highpressure, fast-flow conditions of the subsonic plenum of a supersonic EOIL test reactor. Using the model and the flow reactor results, we have designed and implemented a first-generation catalytic module for the PSI supersonic MIDJet/EOIL reactor. We describe preliminary tests with this module for catalyst coating deposition and enhancement of the small-signal gain observed in the supersonic flow. The observed catalytic effect could significantly benefit the development of high-power electrically driven oxygen-iodine laser systems.

Rawlins, Wilson T.; Lee, Seonkyung; Hicks, Adam J.; Konen, Ian M.; Plumb, Emily P.; Davis, Steven J.

2010-02-01

385

Studies of oxygen-helium discharges for use in electric oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

In recent work, the performance of the Electric Oxygen-Iodine Laser (ElectricOIL), developed in partnership by researchers at the University of Illinois and CU Aerospace, has been greatly improved through systematic study of various components of this new laser technology. One major contribution to the advancement of ElectricOIL technology has been the development of electric discharges capable of producing significant flow rates of the precursor electronically-excited molecular oxygen, O2(a1Delta). O2(a 1Delta) serves as an energy reservoir in the laser system, pumping atomic iodine by near-resonant energy transfer producing gain and laser on the I(2P1/2) ? I(2P3/2 ) transition at 1315 nm. Initial experimental work with radio-frequency discharges showed the importance of controlling O-atom flow rates to reduce quenching losses of energy stored in O2(a1Delta), and determined proper selection of the helium diluent ratio and specific power deposition (power per O2 flow rate). Further experimental investigations with transverse capacitive radio-frequency discharges in O2/He/NO mixtures in the pressure range of 1-100 Torr and power range of 0.1-1.2 kW have indicated that O2(a1Delta) production is a strong function of geometry (transverse gap), excitation frequency, and pressure. These parameters along with gas flow mixture dictate the current density at which the discharge operates, and its modal characteristics (normal vs. abnormal, homogeneous vs. inhomogeneous). A key result is that to encourage efficient O2(a1Delta) production these parameters should be selected in order to promote a homogeneous (low current density) discharge. The discharge behavior is characterized using terminal current-voltage-characteristics, microwave interferometer measurements, and plasma emission intensity measurements. Numerous spectroscopic measurements of O2(a1Delta), oxygen atoms, and discharge excited states are made in order to describe the discharge performance dependent on various parameters. The influence of NO on O-atom flow rates and O2(a1Delta) production is investigated. Progress of laser power extraction since initial reports in 2005 is overviewed.

Zimmerman, Joseph William

386

Experimental investigation of a supersonic swept ramp injector using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

Planar measurements of injectant mole fraction and temperature have been conducted in a nonreacting supersonic combustor configured with underexpanded injection in the base of a swept ramp. The temperature measurements were conducted with a Mach 2 test section inlet in streamwise planes perpendicular to the test section wall on which the ramp was mounted. Injection concentration measurements, conducted in cross flow planes with both Mach 2 and Mach 2.9 free stream conditions, dramatically illustrate the domination of the mixing process by streamwise vorticity generated by the ramp. These measurements, conducted using a nonintrusive optical technique (laser-induced iodine fluorescence), provide an accurate and extensive experimental data base for the validation of computation fluid dynamic codes for the calculation of highly three-dimensional supersonic combustor flow fields.

Hartfield, Roy J.; Hollo, Steven D.; Mcdaniel, James C.

1990-01-01

387

Tomographic imaging of a target directly irradiated in experiments on the Iskra-5 iodine laser facility  

SciTech Connect

We set forth the data of experiments involving direct microtarget irradiation by the 12 second-harmonic beams ({lambda} = 0.66 {mu}m) of iodine laser radiation carried out on the Iskra-5 facility. For microtargets we employed glass shells {approx}500 {mu}m in diameter with {approx}1-{mu}m thick walls, which were filled with a DT mixture at a pressure p{sub DT} {approx} 3-4 atm. In one of these experiments, a tomographic image of the microtarget was recorded from the images obtained using pinhole cameras, which were arranged along seven different directions. The pinhole images were acquired in the X-ray radiation with photon energies above 1.5 keV. The procedure used for reconstructing the volume luminosity of the microtarget is described. An analysis of the tomographic image suggests that the compressed microtarget domain possesses a complex asymmetric shape; 20-30 {mu}m sized structural elements being clearly visible. The resultant data set allowed us to estimate the initial nonuniformity of microtarget surface irradiation by the laser radiation. The rms nonuniformity of microtarget irradiance was estimated at {approx}60 %. (interaction of laser radiation with targets)

Bondarenko, S V; Garanin, R V; Garanin, Sergey G; Zhidkov, N V; Oreshkov, O V; Potapov, S V; Suslov, N A; Frolova, N V [Russian Federal Nuclear Center 'All-Russian Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod region (Russian Federation)

2010-12-29

388

Diode-laser-based absorption spectroscopy diagnostics of a jet-type O2(1?) generator for chemical oxygen-iodine lasers  

Microsoft Academic Search

Using diode-laser-based diagnostics, O2(1?) yield and water vapor fraction were measured at the exit of a jet-type singlet oxygen generator (JSOG) for a chemical oxygen-iodine laser (COIL). Chlorine utilization and gas temperature at the generator exit were also measured, simultaneously. For conditions corresponding to the maximum chemical efficiency of the supersonic COIL energized by the JSOG, the O2(1?) yield, water

D. Furman; B. D. Barmashenko; S. Rosenwaks

1999-01-01

389

Electrode system for electric-discharge generation of atomic iodine in a repetitively pulsed oxygen - iodine laser with a large active volume  

SciTech Connect

Possibilities for increasing the active medium volume of a chemical oxygen - iodine laser (CCOIL) with a pulsed electric-discharge generation of atomic iodine are studied. The reasons are analysed of the low stability of the transverse self-sustained volume discharge in electrode systems with metal cathodes under the conditions of the electric energy input into gas-discharge plasma that are typical for CCOILs: low pressure of mixtures containing a strongly electronegative component, low voltage of discharge burning, low specific energy depositions, and long duration of the current pulse. An efficient electrode system is elaborated with the cathode based on an anisotropically-resistive material, which resulted in a stable discharge in the mixtures of iodide (CH{sub 3}I, n-C{sub 3}H{sub 7}I, C{sub 2}H{sub 5}I) with oxygen and nitrogen at the specific energy depositions of {approx}5 J L{sup -1}, pressures of 10 - 25 Torr, and mixture volume of 2.5 L. (lasers)

Kazantsev, S Yu; Kononov, I G; Podlesnykh, S V; Firsov, K N [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2010-08-03

390

326 IEEE JOURNAL OF QUANTUMELECTRONICS, VOL. QE-18, NO. 3, MARCH 1982 CW Iodine Ion Laser Excited by an Electron Beam  

E-print Network

326 IEEE JOURNAL OF QUANTUMELECTRONICS, VOL. QE-18, NO. 3, MARCH 1982 CW Iodine Ion Laser Excited by an Electron Beam Abstract-CW laser oscillation has been obtained on the 5760.7 and 6127.5 A transitions of a dc electron beam created plasma as a new active medium for CW ion lasers. We report in this paper

Rocca, Jorge J.

391

Multiphase reacting flow modeling of singlet oxygen generators for chemical oxygen iodine lasers.  

SciTech Connect

Singlet oxygen generators are multiphase flow chemical reactors used to generate energetic oxygen to be used as a fuel for chemical oxygen iodine lasers. In this paper, a theoretical model of the generator is presented along with its solutions over ranges of parameter space and oxygen maximizing optimizations. The singlet oxygen generator (SOG) is a low-pressure, multiphase flow chemical reactor that is used to produce molecular oxygen in an electronically excited state, i.e. singlet delta oxygen. The primary product of the reactor, the energetic oxygen, is used in a stage immediately succeeding the SOG to dissociate and energize iodine. The gas mixture including the iodine is accelerated to a supersonic speed and lased. Thus the SOG is the fuel generator for the chemical oxygen iodine laser (COIL). The COIL has important application for both military purposes--it was developed by the US Air Force in the 1970s--and, as the infrared beam is readily absorbed by metals, industrial cutting and drilling. The SOG appears in various configurations, but the one in focus here is a crossflow droplet generator SOG. A gas consisting of molecular chlorine and a diluent, usually helium, is pumped through a roughly rectangular channel. An aqueous solution of hydrogen peroxide and potassium hydroxide is pumped through small holes into the channel and perpendicular to the direction of the gas flow. So doing causes the solution to become aerosolized. Dissociation of the potassium hydroxide draws a proton from the hydrogen peroxide generating an HO{sub 2} radical in the liquid. Chlorine diffuses into the liquid and reacts with the HO{sub 2} ion producing the singlet delta oxygen; some of the oxygen diffuses back into the gas phase. The focus of this work is to generate a predictive multiphase flow model of the SOG in order to optimize its design. The equations solved are the so-called Eulerian-Eulerian form of the multiphase flow Navier-Stokes equations wherein one set of the equations represents the gas phase and another equation set of size m represents the liquid phase. In this case, m is representative of the division of the liquid phase into distinct representations of the various droplet sizes distributed in the reactor. A stabilized Galerkin formulation is used to solve the equation set on a computer. The set of equations is large. There are five equations representing the gas phase: continuity, vector momentum, heat. There are 5m representing the liquid phase: number density, vector momentum, heat. Four mass transfer equations represent the gas phase constituents and there are m advection diffusion equations representing the HO{sub 2} ion concentration in the liquid phase. Thus we are taking advantage of and developing algorithms to harness the power of large parallel computing architectures to solve the steady-state form of these equations numerous times so as to explore the large parameter space of the equations via continuation methods and to maximize the generation of singlet delta oxygen via optimization methods. Presented here will be the set of equations that are solved and the methods we are using to solve them. Solutions of the equations will be presented along with solution paths representing varying aerosol loading-the ratio of liquid to gas mass flow rates-and simple optimizations centered around maximizing the oxygen production and minimizing the amount of entrained liquid in the gas exit stream. Gas-entrained liquid is important to minimize as it can destroy the lenses and mirrors present in the lasing cavity.

Salinger, Andrew Gerhard; Pawlowski, Roger Patrick; Hewett, Kevin B. (Air Force Research Laboratory, Albuquerque, NM); Madden, Timothy J. (Air Force Research Laboratory, Albuquerque, NM); Musson, Lawrence Cale

2008-08-01

392

Implantation of ions produced by the use of high power iodine laser  

NASA Astrophysics Data System (ADS)

The iodine high power Prague Asterix Laser System (PALS), emitting radiation at 438 nm wavelength (3rd-harmonic of a fundamental radiation wavelength equal to 1315 nm), was employed to irradiate in vacuum different metallic targets (Cu, Ag and Ta). The high energy (up to 230 J) short (400 ps) laser pulses produce non-equilibrium plasma expanding mainly along the normal to the target surface. Plasma contains high charge state ions, with maximum charge states of 27 +, 36 + and 49 + for Cu, Ag and Ta, respectively. Time-of-flight (TOF) measurements, performed with the use of an electrostatic ion energy analyser (IEA) placed along the target normal, indicate that the maximum recorded ion kinetic energy is higher than 900 keV for Cu and Ag ions and than 5 MeV for Ta. The laser-produced ions have been implanted into different substrates (polymers, C, Al, Si and Ti) placed at different distances and angles with respect to the target normal. In order to investigate an implantation depth, a density profile of implanted ions and an implanted dose, the samples have been analysed by using the 1.7 MeV helium Rutherford backscattering spectrometry (RBS). The energies of the ions determined with the use of the RBS analysis are in a good agreement with the ion energies measured with the use of the IEA. The results are presented and discussed giving a special attention to the potential of the ion implantation method for modifying the chemical and physical properties of the implanted materials.

Torrisi, L.; Gammino, S.; Mezzasalma, A. M.; Badziak, J.; Parys, P.; Wolowski, J.; Woryna, E.; Krása, J.; Láska, L.; Pfeifer, M.; Rohlena, K.; Boody, F. P.

2003-07-01

393

Frequency Measurement of an Ar+ Laser Stabilized on Narrow Lines of Molecular Iodine at 501.7 nm  

E-print Network

A spectrometer for ultra high-resolution spectroscopy of molecular iodine at wave length 501.7 nm, near the dissociation limit is described. Line shapes about 30 kHz wide (HWHM) were obtained using saturation spectroscopy in a pumped cell. The frequency of an Ar+ laser was locked to a hyperfine component of the R(26)62-0 transition and the first absolute frequency measurement of this line is reported.

Frederic Du Burck; Christophe Daussy; Anne Amy-Klein; Andrei N. Goncharov; Olivier Lopez; Christian Chardonnet; Jean-Pierre Wallerand

2004-11-30

394

Discharge singlet oxygen generator for oxygen iodine laser: I. Experiments with rf discharges at 13.56 and 81 MHz  

Microsoft Academic Search

The scaling on pressure for a discharge singlet oxygen generator based on the rf discharge excitation of O2 flow is studied in the context of the problem of oxygen-iodine laser pumping. With this aim, the evolution of O2(a 1 Deltag) and O_2\\\\,(b\\\\,^{1}\\\\!\\\\Sigma _g^{ + }) molecules as well as O(3P) atoms in 13.56 and 81 MHz discharges at pressures up

O. V. Braginsky; A. S. Kovalev; D. V. Lopaev; Yu A. Mankelevich; O. V. Proshina; T. V. Rakhimova; A. T. Rakhimov; A. N. Vasilieva

2006-01-01

395

Power optimization of small-scale chemical oxygen-iodine laser with jet-type singlet oxygen generator  

Microsoft Academic Search

Studies of power optimization of a 5-cm gain length chemical oxygen-iodine laser (COIL) energized by a jet-type singlet oxygen generator (JSOG) are presented. For 10 mmol\\/s of Cl2 flow rate, output power of 132 W with chemical efficiency of 14.5% was obtained without a water vapor trap, 163 W and 18% were achieved when coholed (173 K). He was introduced

I. Blayvas; B. D. Barmashenko; D. Furman; S. Rosenwaks; M. V. Zagidullin

1996-01-01

396

Frequency Measurement of an Ar+ Laser Stabilized on Narrow Lines of Molecular Iodine at 501.7 nm  

E-print Network

A spectrometer for ultra high-resolution spectroscopy of molecular iodine at wave length 501.7 nm, near the dissociation limit is described. Line shapes about 30 kHz wide (HWHM) were obtained using saturation spectroscopy in a pumped cell. The frequency of an Ar+ laser was locked to a hyperfine component of the R(26)62-0 transition and the first absolute frequency measurement of this line is reported.

Burck, F D; Chardonnet, C; Daussy, C; Goncharov, A N; López, O; Wallerand, J P; Amy-Klein, Anne; Burck, Frederic Du; Chardonnet, Christian; Daussy, Christophe; Goncharov, Andrei N.; Lopez, Olivier; Wallerand, Jean-Pierre; ccsd-00003428, ccsd

2004-01-01

397

A simplified analytic model for gain saturation and power extraction in the flowing chemical oxygen-iodine laser  

Microsoft Academic Search

This paper describes the development of a simplified saturation model (SSM) for predicting power extraction from a chemical oxygen-iodine laser (COIL). Using the Fabry-Perot gain saturation assumption, analytic expressions for COIL extraction efficiency are presented for both constant-density and variable-density cavity conditions. The model treats mirror scattering, nonsaturable distributed losses, and diffractive losses from the mode-limiting aperture and is shown

G. D. Hager; C. A. Helms; K. A. Truesdell; D. Plummer; J. Erkkila; P. Crowell

1996-01-01

398

Effect of nitric oxide on gain and output power of a non-self-sustained electric discharge pumped oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

This letter discusses the effect of nitric oxide on gain and output power of a pulser-sustainer discharge excited oxygen iodine laser. Adding small amounts of NO to the laser mixture (a few hundreds of ppm) considerably increases gain and output power due to (i) O atom titration and resultant slower I* atom quenching and (ii) improved stability of the dc sustainer discharge, which allows stable operation at significantly higher discharge powers. Gain on the 1315nm iodine atom transition and laser power in the M =3 transverse laser cavity are 0.049%/cm and 1.24W, at a flow temperature of T =100K.

Hicks, A.; Bruzzese, J.; Lempert, W. R.; Rich, J. W.; Adamovich, I. V.

2007-08-01

399

Broadband femtosecond OPCPA system driven by the single-shot narrow-band iodine photodissociation laser SOFIA  

NASA Astrophysics Data System (ADS)

A two-stage optical parametric amplifier driven by a frequency-tripled beam from the high-energy iodine laser system SOFIA was built. This single-shot Optical Parametric Chirped Pulse-Amplification facility (OPCPA) and the system synchronizing the pump and signal pulses are described in detail. The chirped seed pulse of a Ti:sapphire oscillator running at the central wavelength of 800 nm is amplified in the two-stage (LBO and KDP) optical parametric amplifier over 108 times. The amplified spectral bandwidth of 68 nm corresponds to the pulse duration of 14 fs when a transform-limited pulse is assumed. This implies a compressed pulse of TW power. Systematic gain measurements reveal a good match with the theoretical predictions. Signal and idler beam fluence profiles are presented. The suitability of the iodine photo-dissociation laser as a pump source for the OPCPA technique is thus proved for the first time experimentally. A distinctive feature of the iodine laser is its very narrow gain bandwidth (<0.1 cm-1) and, therefore, the conventional chirped-pulse amplification technique does not lead to pulse durations at the femtosecond level.

Novák, O.; Tur?i?ová, H.; Smrž, M.; Huynh, J.; Pfeifer, M.; Straka, P.

2012-09-01

400

Explosively pumped photodissociation iodine laser with phase conjugation of super-high quality: modeling and experiment  

NASA Astrophysics Data System (ADS)

A non-steady-state theoretical and mathematical model and a complex of computer codes have been developed for modeling a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjunction (PC) at SBS. The model and the complex of codes taking into account 3D of space consist of two blocks. The first block is devoted to detailed modeling of the SBS mirror consisting of an angular selector of Stokes radiation, an ordered raster of small diffraction lenses, a main focusing lens, and a SBS cell. The second block describes the dynamics of radiation in the laser system as a whole with using SBS mirror parameters calculated in the first block. The model takes into account parasitic reflections of laser radiation from the elements of the optical scheme, intrinsic amplified spontaneous emission of the amplifiers, radiation losses in the optical path, non-uniformity of gain, and radiation refraction on optical non-uniformaties of gain, and radiation refraction on optical non-uniformities of the active medium caused by a shock wave. As a result of calculations an optimal configuration of the SBS mirror has been determined, possessing unique properties if compared to the existing specimens of the SBS mirrors. It stably gives a nearly ideal quality of PC at any level of SBS saturation, i.e. any reflection coefficient that is confirmed by experimental laboratory investigations. Modeling of the laser system as a whole at working mixture 25 Torr C3F7I+125 Torr Xe and amplifier aperture 15 cm has been shown a good agreement of calculated results with available experimental data in energy, time dependence of power and Strehl number of output radiation. The considered EPDL has output energy of about 400 J and brightness of about 1012 J/ster. It is shown that parasitic reflections of laser radiation from the ends of amplifiers and elements of the optical scheme with a coefficient exceeding 10-7 considerably decrease the brightness of EPDL.

Starikov, Fedor A.; Dolgopolov, Yu. V.; Dudov, A. M.; Kirillov, Gennadi A.; Kochemasov, Gennady G.; Kulikov, Stanislav M.; Ladagin, Vladimir K.; Manachinsky, A. N.; Pevny, S. N.; Shkapa, A. F.; Smyshlyaev, Sergey P.; Sukharev, Stanislav A.; Zykov, L. I.

2003-10-01

401

Investigation of explosively pumped photodisassociation iodine laser with phase conjugation of super-high quality  

NASA Astrophysics Data System (ADS)

A non-steady-state theoretical and mathematical model and a complex of computer codes have been developed for modeling a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjugation (PC) at SBS. The model and the complex of codes taking into account 3D of space consist of two blocks. The first block is devoted to detailed modeling of the SBS mirror consisting of an angular selector of Stokes radiation, an ordered raster of small diffraction lenses, a main focusing lens, and a SBS cell. The second block describes the dynamics of radiation in the laser system as a whole with using SBS mirror parameters calculated in the first block. The model takes into account parasitic reflections of laser radiation from the elements of the optical scheme, intrinsic amplified spontaneous emission of the amplifiers, radiation losses in the optical path, non-uniformity of gain, and radiation refraction on optical non-uniformities of the active medium caused by a shock wave. As a result of calculations an optimal configuration of the SBS mirror has been determined, possessing unique properties if compared to the existing specimens of the SBS mirrors. It stably gives a nearly ideal quality of PC at any level of SBS saturation, i.e. any reflection coefficient that is confirmed by experimental laboratory investigations. Modeling of the laser sytem with two amplifiers at working mixture 25 Torr C3F7I+125 Torr Xe and amplifier aperture 15 cm has been shown a good agreement of calculated result with available experimental data in energy, time dependence of power and Strehl number of output radiation. The considered EPDL has output energy of about 400 J and brightness of about 1012 J/ster. Calculations show that under rising the density flux of input signal from the master oscillator in a range 0.01-20 W/cm2, the brightness of the EPDL output radiation increase whereas the full energy varies relativley slightly. It is shown that parasitic reflections of laser radiation from the ends of amplifiers and elements of the optical scheme with a coefficient exceeding 10-7 considerably decrease the axial brightness of output radiation. In order to reduce the harmful effect of parasitic reflections on brightness, the distance between the ampfiers should be increased.

Starikov, Fedor A.; Dolgopolov, Yu. V.; Dudov, A. M.; Gerasimenko, Natalia N.; Kirillov, Gennadi A.; Kochemasov, Gennady G.; Kulikov, Stanislav M.; Ladagin, Vladimir K.; Pevny, S. N.; Shkapa, A. F.; Smyshlyaev, Sergey P.; Sukharev, Stanislav A.; Zykov, L. I.

2003-11-01

402

Frequency-modulation saturation spectroscopy of molecular iodine hyperfine structure near 640 nm with a diode laser source  

E-print Network

In a frequency-modulation spectroscopy experiment, using the radiation from a single frequency diode laser, the spectra of molecular iodine hyperfine structure near 640 nm were recorded on the transition $B^3\\Pi_{0_u^{+}}-X^1\\Sigma^+_{g}$. The frequency reference given by the value of the modulation frequency (12.5 MHz in given experiment) allows determination of the frequency differences between hyperfine components with accuracy better than 0.1 MHz using the fitting procedure in experiment with only one laser.

V. M. Khodakovskiy; V. I. Romanenko; I. V. Matsnev; R. A. Malitskiy; A. M. Negriyko; L. P. Yatsenko

2009-12-16

403

Frequency-modulation saturation spectroscopy of molecular iodine hyperfine structure near 640 nm with a diode laser source  

E-print Network

In a frequency-modulation spectroscopy experiment, using the radiation from a single frequency diode laser, the spectra of molecular iodine hyperfine structure near 640 nm were recorded on the transition $B^3\\Pi_{0_u^{+}}-X^1\\Sigma^+_{g}$. The frequency reference given by the value of the modulation frequency (12.5 MHz in given experiment) allows determination of the frequency differences between hyperfine components with accuracy better than 0.1 MHz using the fitting procedure in experiment with only one laser.

Khodakovskiy, V M; Matsnev, I V; Malitskiy, R A; Negriyko, A M; Yatsenko, L P

2009-01-01

404

Optically pumped Iodine monofluoride B/sup 3/Pi(O/sup +/). -->. X/sup 1/. sigma. /sup +/ laser  

SciTech Connect

An optically pumped iodine monofluoride laser operating on the B/sup 3/Pi(O/sup +/)..-->..X/sup 2/..sigma../sup +/ system has been demonstrated. Ground-state IF was produced by the reaction of I/sub 2/+F/sub 2/ and subsequently excited with a high-energy, broadband dye laser. Lasing was observed on the (2,10), (3,11), (4,9), and (4,10) transitions covering the wavelength range 7200--6500 A.

Davis, S.J.; Hanko, L.

1980-10-15

405

Advanced COIL based on atomic iodine generation using gaseous reactants  

Microsoft Academic Search

Development of a Chemical Oxygen-Iodine Laser (COIL) with alternative ways of atomic iodine generation is aimed at power increase and simplified laser operation. Advantages of chemical generation of atomic iodine using gaseous reactants directly in the laser medium are confronted with disadvantages of using molecular iodine as a source of atomic iodine in conventional COIL devices. Some recent results on

Jarmila Kodymova; Otomar Spalek; Miroslav Censky; Vit Jirasek; Gordon D. Hager

2004-01-01

406

Flowfield measurements in a model scramjet combustion using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

Preliminary designs were completed for an iodine mixing chamber and the optical setup to be used with a modified wind tunnel in obtaining accurate, spatially resolved measurements of variables in the flowfield of a model nonreacting scramjet combustor. Schematics of the iodine-seeded wind tunnel and a sketch of the charcoal filter for removing the iodine are included along with a cutaway section of the laboratory.

Mcdaniel, J. C., Jr.

1984-01-01

407

0/sub 2/(/sup 1/. delta. ) generation mechanisms in the chemically pumped iodine laser  

SciTech Connect

The reactivity of Cl/sub 2/ with aqueous H/sub 2/O/sub 2/, both with and without added base, was investigated in a static bulb. The rate data for Cl/sub 2/ absorption in these solutions are explained in terms of a diffusion-reaction model, and the results are consistent with the assumption that the reaction responsible for O/sub 2/(/sup 1/..delta..) production in the O/sub 2/(/sup 1/..delta..) generator utilized in the chemically pumped iodine laser is a direct reaction between Cl/sub 2/ and HO/sup -//sub 2/ at the generator gas-liquid interface. The data indicate that the probability of loss of a Cl/sub 2/ molecule that strikes the alkaline H/sub 2/O/sub 2/ gas-liquid interface is approx.10/sup -2/. The solubility of Cl/sub 2/ in H/sub 2/O/sub 2/-H/sub 2/O mixtures as well as implications of the experiment for practical O/sub 2/(/sup 1/..delta..) generators are discussed.

Richardson, R.J.; Kelley, J.D.; Wiswall, C.E.

1981-02-01

408

Multiline (480--496 nm) discharge-pumped iodine monofluoride laser  

SciTech Connect

Lasing at 478.7, 484.7, 490.7, and 496.5 nm has been observed on the E..-->..A/sup 3/Pi (bound..-->..bound) band of the IF (iodine monofluoride) molecule in discharge-pumped He, Ar, CF/sub 3/I, and NF/sub 3/ gas mixtures. Oscillation was obtained using a stable optical cavity with output coupling mirror transmission of 0.2 and 92%. For a 99.7%-He, 0.2%-NF/sub 3/, and 0.1%-CF/sub 3/I (p/sub total/approx. =1540 Torr) gas mixture and Tapprox.92% (quartz flat), output pulse energies of approx.0.35 mJ in a approx.15-ns FWHM pulse (peak output power > or approx. =24 kW) were measured. Optimization of the cavity output coupling and increased Ar pressures in conjunction with the use of an attaching gas (to raise the discharge E/N) are expected to improve the output energy and, consequently, the overall efficiency of this blue-green laser.

Dlabal, M.L.; Hutchinson, S.B.; Eden, J.G.; Verdeyen, J.T.

1980-11-15

409

Computer-controlled multi-parameter mapping of 3D compressible flowfields using planar laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A computer-controlled technique, using planar laser-induced iodine fluorescence, for measuring complex compressible flowfields is presented. A new laser permits the use of a planar two-line temperature technique so that all parameters can be measured with the laser operated narrowband. Pressure and temperature measurements in a step flowfield show agreement within 10 percent of a CFD model except in regions close to walls. Deviation of near wall temperature measurements from the model was decreased from 21 percent to 12 percent compared to broadband planar temperature measurements. Computer-control of the experiment has been implemented, except for the frequency tuning of the laser. Image data storage and processing has been improved by integrating a workstation into the experimental setup reducing the data reduction time by a factor of 50.

Donohue, James M.; Victor, Kenneth G.; Mcdaniel, James C., Jr.

1993-01-01

410

Closed-loop wavelength stabilization of an optical parametric oscillator as a front end of a high-power iodine laser chain  

NASA Astrophysics Data System (ADS)

We present a complex stabilization and control system for a commercially available optical parametric oscillator. The system is able to stabilize the oscillator's output wavelength at a narrow spectral line of atomic iodine with subpicometer precision, allowing utilization of this solid-state parametric oscillator as a front end of a high-power photodissociation laser chain formed by iodine gas amplifiers. In such setup, a precise wavelength matching between the front end and the amplifier chain is necessary due to extremely narrow spectral lines of the gaseous iodine (˜20pm). The system is based on a personal computer, a heated iodine cell, and a few other low-cost components. It automatically identifies the proper peak within the iodine absorption spectrum, and then keeps the oscillator tuned to this peak with high precision and reliability. The use of the solid-state oscillator as the front end allows us to use the whole iodine laser system as a pump laser for the optical parametric chirped pulse amplification, as it enables precise time synchronization with a signal Ti:sapphire laser.

Kral, L.

2007-05-01

411

Kinetic model of a space-based, Br(4 (2)P 1/2 {r_arrow} 4 (2)P 3/2) laser pumped by solar photolysis of IBr  

SciTech Connect

A kinetic model of the directly solar-pumped, atomic bromine laser -- operating on the Br (4 (2)P 1/2 {r_arrow} 4 (2)P 3/2) transition under IBr photolysis -- was developed, executed, and interpreted. In recognition of an evolving national interest in space-based laser development, the model presumed operation on a space station platform. Results indicate that a well-engineered IBr laser is capable of generating 1.2 kilowatts of continuous-wave (CW) power under a pumping concentration of 20,000 solar units. Such performance translates to an efficiency of roughly 0.29%, appreciably better than the 0.1% ascribed to the heretofore leading solar-pumped competitor. An extensive analysis of kinetic data suggests the unanticipated conclusion that, under proper parameter selection, sustained CW oscillation can be achieved absent any flow mechanism whatsoever. This result seems most strongly predicated upon proper bandpass discrimination: a 457--545 nm range of incidence produced optimal results. Sensitivity analysis revealed a strong degree of competition among the laser`s constituent processes; two-body quenching and exchange reactions were predominant. With the significant exception of iodine recombination, three-body processes were negligible. Thermal increases, as well as rapid growth of atomic iodine, appear to pose the greatest kinetic threat to CW lasing.

Behnken, B.N.

1999-03-01

412

Effect of nitric oxide on gain and output power of a non-self-sustained electric discharge pumped oxygen-iodine laser  

Microsoft Academic Search

This letter discusses the effect of nitric oxide on gain and output power of a pulser-sustainer discharge excited oxygen iodine laser. Adding small amounts of NO to the laser mixture (a few hundreds of ppm) considerably increases gain and output power due to (i) O atom titration and resultant slower I* atom quenching and (ii) improved stability of the dc

A. Hicks; J. Bruzzese; W. R. Lempert; J. W. Rich; I. V. Adamovich

2007-01-01

413

O2(1?) production and gain in plasma pumped oxygen iodine lasers: consequences of NO and NO2 additives  

NASA Astrophysics Data System (ADS)

The 1.315 µm [I(2P1/2) ? I(2P3/2)] transition of atomic iodine in the chemical oxygen-iodine laser (COIL) is pumped by sequential reactions of I2 and I with O2(1?). In electrically pumped systems (eCOILs), electron impact excitation of O2 produces the O2(1?) and also produces O atoms through dissociative excitation. The O atoms, through reactions with I2, I(2P1/2) and I(2P3/2), lead to dissociation of I2, quenching of the upper laser level and removal of the lower laser level. While dissociating I2 is potentially beneficial, quenching of the upper laser level is detrimental and so management of the O atom density is necessary to maximize laser gain. In this regard, NO and NO2 additives have been used to manage the O atom density by cyclically reacting with O and I. In this paper, results from a computational investigation of eCOIL systems using plug flow and two-dimensional models are discussed where NO and NO2 additives are used. The system is a flowing plasma sustained in He/O2/NO mixtures with downstream injection of NO2 followed by injection of I2. We found that addition of NO and NO2 is effective in managing the density of O atoms and maximizing gain by minimizing quenching of the upper laser level. We found that by optimizing the additives, laser gain can be maximized even though O2(1?) densities may be lower due to the management of quenching and dissociation reactions.

Arakoni, Ramesh A.; Babaeva, Natalia Y.; Kushner, Mark J.

2007-08-01

414

Prototype of a Laser-Induced Fluorescence Ground-Based Instrument for Measurements of Atmospheric Iodine Monoxide (IO)  

NASA Astrophysics Data System (ADS)

High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer: (1) IO participates in depletion episodes of O3 and in the removal of mercury in the Arctic polar spring by enhancing atomic Br mixing ratios. Recent observations and computer simulations suggest that mercury sequestration is closely tied to halogen photochemistry and that gaseous atomic Hg depletion can be enhanced significantly by the presence of small amounts of iodine-containing compounds. (2) IO and higher- order iodine oxides are involved in the formation of new particles in coastal marine environments. Studies using smog chamber experiments simulating coastal atmospheric conditions have demonstrated that new particles can form from condensable iodine-containing vapors and that their concentrations over the open ocean are sufficient to influence marine particle formation. (3) IO has also been shown to affect the oxidizing capacity of the troposphere by altering the partitioning of NO2/NO and HO2/HO and by activating chlorine and bromine in sea salt aerosols. In the stratosphere, these same processes can lead to enhanced ozone loss rates. Detailed photochemical models that include iodine photochemistry, however, are hampered by the lack of observational data. The distribution of IO in vertical, horizontal, and temporal coordinates is unknown, so the impact of IO on global photochemistry cannot be predicted. The resolution of these important scientific issues requires an in situ IO instrument. A fully functional nanosecond Nd:YAG-pumped Ti:Sapphire laser system and a prototype IO ground-based instrument have been built in our lab. With the current setup, the laser system was situated 10 m from the field station, and the laser light was coupled via an optical fiber. With the use of highly efficient fluorescence detection optics and photon counting techniques, sensitivities of better than 0.1 ppt in 1 s for IO was achieved in the laboratory and 1-2 ppt in the field. The design of the instrument and data acquisition system will be described. The prototype was deployed to the Northeastern University Marine Science Center in Nahant, MA in August 2007. Laminaria macroalgae is known to be responsible for coastal I2 emissions, and Nahant has extensive populations of kelp within the shallow subtidal zone. Results from the field mission will be reported, and future developments of the instrument will be discussed. It is expected that a modified version of this new system will, in time, be capable of being integrated with the existing instrumentation used for the detection of halogen (ClO, BrO), nitrogen (NO2), and hydrogen (OH and HO2) free radicals.

Co, D. T.; Thurlow, M. E.; Hanisco, T. F.; Lapson, L. B.; Anderson, J. G.

2007-12-01

415

Prototype of a Laser-Induced Fluorescence Ground-Based Instrument for Measurements of Atmospheric Iodine Monoxide (IO)  

NASA Astrophysics Data System (ADS)

High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer: (1) IO participates in depletion episodes of O3 and in the removal of mercury in the Arctic polar spring by enhancing atomic Br mixing ratios. Recent observations and computer simulations suggest that mercury sequestration is closely tied to halogen photochemistry and that gaseous atomic Hg depletion can be enhanced significantly by the presence of small amounts of iodine-containing compounds. (2) IO and higher- order iodine oxides are involved in the formation of new particles in coastal marine environments. Studies using smog chamber experiments simulating coastal atmospheric conditions have demonstrated that new particles can form from condensable iodine-containing vapors and that their concentrations over the open ocean are sufficient to influence marine particle formation. (3) IO has also been shown to affect the oxidizing capacity of the troposphere by altering the partitioning of NO2/NO and HO2/HO and by activating chlorine and bromine in sea salt aerosols. In the stratosphere, these same processes can lead to enhanced ozone loss rates. Detailed photochemical models that include iodine photochemistry, however, are hampered by the lack of observational data. The distribution of IO in vertical, horizontal, and temporal coordinates is unknown, so the impact of IO on global photochemistry cannot be predicted. The resolution of these important scientific issues requires an in situ IO instrument. A fully functional nanosecond Nd:YAG-pumped Ti:Sapphire laser system and a prototype IO ground-based instrument have been built in our lab. With the current setup, the laser system was situated 10 m from the field station, and the laser light was coupled via an optical fiber. With the use of highly efficient fluorescence detection optics and photon counting techniques, sensitivities of better than 0.1 ppt in 1 s for IO was achieved in the laboratory and 1-2 ppt in the field. The design of the instrument and data acquisition system will be described. The prototype was initially deployed to the Northeastern University Marine Science Center in Nahant, MA in August 2007. Recent developments in the design and sensitivity of the instrument will be discussed. A modified version of this new system will, in time, be capable of being integrated with the existing instrumentation used for the detection of halogen (ClO, BrO), nitrogen (NO2), and hydrogen (OH and HO2) free radicals.

Thurlow, M. E.; Co, D. T.; Hanisco, T. F.; Lapson, L. B.; Anderson, J. G.

2008-12-01

416

Strong-field ionization of molecular iodine traced with XUV pulses from a free-electron laser  

NASA Astrophysics Data System (ADS)

Ultrafast dynamics of a molecular wave packet created by a strong 120-fs near-infrared (800 nm) laser pulse in iodine has been probed by synchronized 13.4-nm, 35-fs extreme-ultraviolet pulses delivered by the free-electron laser facility in Hamburg, FLASH. The kinetic energy release of the multiply charged ionic fragments reveals three essential steps of strong-field-induced molecular fragmentation dynamics: (i) The creation of I22+ and (I22+)* molecular ions proceeds within (75 ± 15) fs full-width-at-half-maximum. (ii) With the onset of the I22+ fragmentation the probability to lose a further electron within the same optical laser pulse rises with increasing I+—I+ internuclear separation and reaches its maximum after ˜30 fs with respect to the pulse maximum. (iii) Charge separation into the I22+?I2++I dissociative channel with an asymmetric charge distribution is completed after (121 ± 22) fs.

Krikunova, Maria; Maltezopoulos, Theophilos; Wessels, Philipp; Schlie, Moritz; Azima, Armin; Gaumnitz, Thomas; Gebert, Thomas; Wieland, Marek; Drescher, Markus

2012-10-01

417

The I2 dissociation mechanisms in the chemical oxygen-iodine laser revisited.  

PubMed

The recently suggested mechanism of I(2) dissociation in the chemical oxygen-iodine laser (COIL) [K. Waichman, B. D. Barmashenko, and S. Rosenwaks, J. Appl. Phys. 106, 063108 (2009); and J. Chem. Phys. 133, 084301 (2010)] was largely based on the suggestion of V. N. Azyazov, S. Yu. Pichugin, and M. C. Heaven [J. Chem. Phys. 130, 104306 (2009)] that the vibrational population of O(2)(a) produced in the chemical generator is high enough to play an essential role in the dissociation. The results of model calculations based on this mechanism agreed very well with measurements of the small signal gain g, I(2) dissociation fraction F, and temperature T in the COIL. This mechanism is here revisited, following the recent experiments of M. V. Zagidullin [Quantum Electron. 40, 794 (2010)] where the observed low population of O(2)(b, v = 1) led to the conclusion that the vibrational population of O(2)(a) at the outlet of the generator is close to thermal equilibrium value. This value corresponds to a very small probability, ?0.05, of O(2)(a) energy pooling to the states O(2)(X,a,b, v > 0). We show that the dissociation mechanism can reproduce the experimentally observed values of g, F, and T in the COIL only if most of the energy released in the processes of O(2)(a) energy pooling and O(2)(b) quenching by H(2)O ends up as vibrational energy of the products, O(2)(X,a,b), where the vibrational states v = 2 and 3 are significantly populated. We discuss possible reasons for the differences in the suggested vibrational population and explain how these differences can be reconciled. PMID:22755574

Waichman, K; Barmashenko, B D; Rosenwaks, S

2012-06-28

418

Analytic study of the chain dark decomposition reaction of iodides - atomic iodine donors - in the active medium of a pulsed chemical oxygen-iodine laser: 2. Limiting parameters of the branching chain dark decomposition reaction of iodides  

SciTech Connect

The final stages in the development of a branching chain decomposition reaction of iodide in the active medium of a pulsed chemical oxygen-iodine laser (COIL) are analysed. Approximate expressions are derived to calculate the limiting parameters of the chain reaction: the final degree of iodide decomposition, the maximum concentration of excited iodine atoms, the time of its achievement, and concentrations of singlet oxygen and iodide at that moment. The limiting parameters, calculated by using these expressions for a typical composition of the active medium of a pulsed COIL, well coincide with the results of numerical calculations. (active media)

Andreeva, Tamara L; Kuznetsova, S V; Maslov, Aleksandr I; Sorokin, Vadim N [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2009-08-31

419

Quantitative measurement of transverse injector and free stream interaction in a nonreacting SCRAMJET combustor using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A preliminary quantitative study of the compressible flowfield in a steady, nonreacting model SCRAMJET combustor using laser-induced iodine fluorescence (LIIF) is reported. Measurements of density, temperature, and velocity were conducted with the calibrated, nonintrusive, optical technique for two different combustor operating conditions. First, measurements were made in the supersonic flow over a rearward-facing step without transverse injection for comparison with calculated pressure profiles. The second configuration was staged injection behind the rearward-facing step at an injection dynamic pressure ratio of 1.06. These experimental results will be used to validate computational fluid dynamic (CFD) codes being developed to model supersonic combustor flowfields.

Fletcher, D. G.; Mcdaniel, J. C.

1987-01-01

420

Planar measurement of flow field parameters in a nonreacting supersonic combustor using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A nonintrusive optical technique, laser-induced iodine fluorescence, has been used to obtain planar measurements of flow field parameters in the supersonic mixing flow field of a nonreacting supersonic combustor. The combustor design used in this work was configured with staged transverse sonic injection behind a rearward-facing step into a Mach 2.07 free stream. A set of spatially resolved measurements of temperature and injectant mole fraction has been generated. These measurements provide an extensive and accurate experimental data set required for the validation of computational fluid dynamic codes developed for the calculation of highly three-dimensional combustor flow fields.

Hartfield, Roy J., Jr.; Hollo, Steven D.; Mcdaniel, James C.

1990-01-01

421

Chemical Oxygen-Iodine Laser Diluted by CO2/N2 Buffer Gases with a Cryosorption Vacuum Pump  

NASA Astrophysics Data System (ADS)

Experiments were carried out on a verti-chemical oxygen-iodine laser (COIL), which was designed for N2 and energized by a square-pipe jet singlet oxygen generator (JSOG). A cryosorption vacuum pump was used as the pressure recovery system for CO2 and N2 buffer gases. The output power with CO2 was 27.3% lower than that with N2, but the zeolite bed showed an adsorption capacity threefold higher for CO2 than for N2 in the continuous operation with a Cl2 flow rate of 155 mmol/s and a total flow rate of 430±3 mmol/s.

Xu, Mingxiu; Sang, Fengting; Jin, Yuqi; Fang, Benjie; Chen, Fang; Geng, Zicai; Li, Yongzhao

2008-11-01

422

REVIEWS OF TOPICAL PROBLEMS: Gas lasers with solar excitation  

NASA Astrophysics Data System (ADS)

CONTENTS 1. Introduction 703 2. General requirements for laser media using solar excitation 704 3. Lasers with direct excitation by solar light 705 3.1. Basic characteristics of laser media. 3.2. Photodissociation Br2-CO2 lasers. 3.3. Interhalogen molecule lasers. 3.4. Iodine lasers. 3.5. Alkali metal vapor lasers. 4. Lasers with thermal conversion of solar pumping 709 4.1. General considerations. 4.2. CO2 laser with excitation in a black body cavity and with gas flow. 4.3. cw CO2 laser without gas flow. 5. Space laser media with solar excitation 713 5.1. Population inversion of molecular levels in the outer atmosphere of the Earth. 5.2. Laser effect in the atmospheres of Venus and Mars. 5.3. Terrestrial experimental technique for observing infrared emission in the atmospheres of planets. 5.4. Designs for laser systems in the atmospheres of Venus and Mars. 6. Conclusions 717 References 717

Gordiets, B. F.; Panchenko, Vladislav Ya

1986-07-01

423

Influence of parameters of gas medium on the fluorescence of iodine molecules 129I2, 127I129I and 127I2 excited by semiconductor laser radiation  

NASA Astrophysics Data System (ADS)

Calculated and experimental results of studies of the influence of vapor temperature of iodine molecules (129I2, 127I129I, and 127I2) and pressure of the analyzed medium on the intensity of fluorescence of the molecules excited by semiconductor laser radiation in the red spectrum region are reported. It is demonstrated that depending on the wavelength of laser radiation there exist different ranges of temperatures and pressure values at which the fluorescence intensities of each of the indicated iodine molecules reach their maximum values.

Kireev, S. V.; Shnyrev, S. L.

2012-12-01

424

A Ground-Based Instrument for the Laser-Induced Fluorescence Detection of Coastal Iodine Monoxide (IO)  

NASA Astrophysics Data System (ADS)

The photochemistry of iodine monoxide (IO) within the marine boundary layer plays a role in the catalytic loss cycles of surface ozone and potentially leads to the nucleation of marine aerosols. Biogenic emissions of molecular iodine and organo-halide precursor molecules account for the largest sources of IO in marine and coastal environments. Due to the inhomogeneous distribution of atmospheric IO in conjunction with low mixing ratios of less than 10 ppt, high sensitivity in-situ measurements are needed in order to better understand the impact of IO photochemistry in a quantifiable way. To address these challenges, a laser-induced fluorescence instrument has been developed, with a nanosecond-pulsed Nd:YAG-pumped Ti:Sapphire laser system. Through efficient optical design and fluorescence detection, we are able to operate in the sensitivity threshold of 1 ppt per minute for IO. Further design considerations included the development of a mobile, weatherproof instrument configuration, which can sustain deployment in a variety of field conditions. In order to validate the detection technique, the instrument was deployed at Shoals Marine Laboratory in Maine from August-September 2011. Instrument design considerations as well as preliminary results of the detection of IO from laminaria digitata, a kelp species present in coastal New England sites, will be presented.

Hannun, R. A.; Thurlow, M. E.; O'Brien, A.; Co, D. T.; Hanisco, T. F.; Lapson, L. B.; Anderson, J.

2011-12-01

425

2D gasdynamic simulation of the kinetics of an oxygen-iodine laser with electric-discharge generation of singlet oxygen  

SciTech Connect

The kinetic processes occurring in an electric-discharge oxygen-iodine laser are analyzed with the help of a 2D (r, z) gasdynamic model taking into account transport of excited oxygen, singlet oxygen, and radicals from the electric discharge and their mixing with the iodine-containing gas. The main processes affecting the dynamics of the gas temperature and gain are revealed. The simulation results obtained using the 2D model agree well with the experimental data on the mixture gain. A subsonic oxygen-iodine laser in which singlet oxygen is generated by a 350 W transverse RF discharge excited in an oxygen flow at a pressure P = 10 Torr and the discharge tube wall is covered with mercury oxide is simulated. The simulated mixing system is optimized in terms of the flow rate and the degree of preliminary dissociation of the iodine flow. The optimal regime of continuous operation of a subsonic electric-discharge oxygen-iodine laser is found.

Chukalovsky, A. A.; Rakhimova, T. V.; Klopovsky, K. S.; Mankelevich, Yu. A.; Proshina, O. V. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2011-03-15

426

Investigation of possibilities for solar-powered high-energy lasers in space  

NASA Technical Reports Server (NTRS)

Solar pumped lasers were investigated. The literature was reviewed for possible solar laser candidates from optical pumping experiments. A baseline CO electric discharge laser system was shown to be technically feasible. The most promising direct solar pumped laser was identified to be CF3I. Using the 'STAG' solar laser concept and CF3I, it was found that such a system could be weight competitive with the baseline CO laser system.

1982-01-01

427

Investigation of the characteristics of the preamplifier stages of a short-pulse iodine laser  

Microsoft Academic Search

Measurements were made of the amplification cross section at the frequency of the F' = 3?F = 4 transition. The luminescence line broadening and shift due to different buffer gases were determined. The magnitude and lifetime of the population inversion were investigated. The relaxation time of the level populations of the excited 2P1\\/2 state of atomic iodine was determined experimentally.

V. A. Katulin; V Yu Nosach; A. L. Petrov

1979-01-01

428

Experimental study of cutting thick aluminum and steel with a chemical oxygen-iodine laser using an N2 or O2 gas assist  

Microsoft Academic Search

A chemical oxygen-iodine laser (COIL) was used for cutting aluminum and carbon steel. Cut depths of 20 mm were obtained in aluminum and 41 mm in carbon steel using an N2 gas assist and 5-6 kW of power on target. The same laser at the same power level produced a cut depth of 65 mm in carbon steel with an

David L. Carroll; James A. Rothenflue

1997-01-01

429

Interpretation of In-Situ Measurements of Iodine Monoxide in Coastal Regions Using Laser-Induced Fluorescence Spectroscopy  

NASA Astrophysics Data System (ADS)

Iodine species are present in coastal and open ocean regions due to the release of I2 and iodocarbons from macro and micro algae. The photolysis of these molecules yields iodine atoms, which react with ozone to produce iodine monoxide (IO). IO is involved in ozone depletion cycles, the partitioning of HOx and NOx, and the formation and growth of new particles. A novel point source Laser Induced Fluorescence (LIF) instrument was deployed to measure IO in September 2006 at Roscoff, France as part of the Reactive Halogens in the Marine Boundary Layer (RHaMBLe) programme (1 instrument uncertainty = 23%)1. The maximum IO mixing ratio was 30 ± 7.1 pptV (10 s integration period, limit of detection = 1.4 pptV) at this semi-polluted coastal site (NOx levels = 1 - 5 ppbV). The closest macroalgae beds known to strongly emit I2 (laminaria) were ~ 300 m from the LIF instrument. IO displayed a strong anti-correlation with tidal height which is consistent with previous studies. IO was also dependent on solar irradiation and meteorological conditions. The dominant source of IO at this site was the photolysis of I2. The measurements provided by this instrument aim to address the main uncertainties associated with iodine chemistry. Co-ordinated measurement of IO by point source (LIF) and spatially averaged (Long Path Differential Optical Absorption Spectroscopy) instruments confirm the presence of IO hotspots due to non-uniform macroalgae distribution at this location (resulting in a spatially variable I2 source). The ratio of point source/spatially averaged IO is determined by meteorological conditions and distance of the instrument from macroalgae beds. Co-located point source I2 (Broadband Cavity Ringdown Spectroscopy) and IO (LIF) measurements correlated on some days but cannot be explained by our current knowledge of iodine chemistry. The influence of NOx on IO has been investigated. The detection of IO by LIF at the Roscoff site shows that IO can survive in a high NOx environment, at a distance from the iodine source region. The LIF measurements display an anti-correlation with NOx. A modelling study shows that this is due to an iodine recycling scheme via IONO2. The effect of NO2 is to initially lead to IO suppression (displayed by an anti-correlation of IO with NOx) and then to prolong the atmospheric lifetime of IO through decomposition of IONO2. Night-time IO was detected on two out of four nights at levels of 1 - 2 pptV, providing further evidence for the presence of night-time IO. The night-time source of I atoms is proposed to be via I2 + NO3 â?? I + INO3, 2,3. Co-located point source measurements of IO and particle number provide clear evidence for the link between IO and new particle formation. Over 18 days of simultaneous measurements, IO and particle number displayed a linear relationship. On all occasions, IO levels increased before an increase in particle number was observed. The influence of IO on the important daytime oxidants OH and HO2 has been investigated by modelling studies. IO was found to decrease the HO2/OH ratio due conversion of HO2 to OH via (HO2 + IO â?? HOI, HOI + h? â?? OH + I). The high levels of IO detected at Roscoff can result in an enhancement of OH at up to 50%. However, the impact of IO on HOx decreases as NOx levels increase, until IO actually results in a decrease in OH (NOx > 1.55 ppbV). Whalley et. al. (2007), J. Atmos. Chem. 58: 19 - 39. Chambers, R. M. et al (1992), Journal of Physical Chemistry, 96, 3321-3331. Saiz-Lopez, A. and J. M. C. Plane (2004), GRL, 31, 19215-19218.

Furneaux, K. L.; Whalley, L. K.; Heard, D. E.

2009-04-01

430

Reduced dimer production in solar-simulator-pumped continuous wave iodine lasers based on model simulations and scaling and pumping studies  

NASA Technical Reports Server (NTRS)

A numerical rate equation model for a continuous wave iodine laser with longitudinally flowing gaseous lasant is validated by approximating two experiments that compare the perfluoroalkyl iodine lasants n-C3F7I and t-C4F9I. The salient feature of the simulations is that the production rate of the dimer (C4F9)2 is reduced by one order of magnitude relative to the dimer (C3F7)2. The model is then used to investigate the kinetic effects of this reduced dimer production, especially how it improves output power. Related parametric and scaling studies are also presented. When dimer production is reduced, more monomer radicals (t-C4F9) are available to combine with iodine ions, thus enhancing depletion of the laser lower level and reducing buildup of the principal quencher, molecular iodine. Fewer iodine molecules result in fewer downward transitions from quenching and more transitions from stimulated emission of lasing photons. Enhanced depletion of the lower level reduces the absorption of lasing photons. The combined result is more lasing photons and proportionally increased output power.

Costen, Robert C.; Heinbockel, John H.; Miner, Gilda A.; Meador, Willard E., Jr.; Tabibi, Bagher M.; Lee, Ja H.; Williams, Michael D.

1995-01-01

431

ACTIVE MEDIA: Analytic study of the chain dark decomposition reaction of iodides --- atomic iodine donors --- in the active medium of a pulsed chemical oxygen---iodine laser: 1. Criteria for the development of the branching chain dark decomposition reaction of iodides  

Microsoft Academic Search

The scheme of chemical processes proceeding in the active medium of a pulsed chemical oxygen---iodine laser (COIL) is analysed. Based on the analysis performed, the complete system of differential equations corresponding to this scheme is replaced by a simplified system of equations describing in dimensionless variables the chain dark decomposition of iodides --- atomic iodine donors, in the COIL active

Tamara L. Andreeva; S. V. Kuznetsova; Aleksandr I. Maslov; Vadim N. Sorokin

2009-01-01

432

Compact XeF ({ital C}{r_arrow}{ital A}) and iodine laser optically pumped by a surface discharge  

SciTech Connect

A compact surface-discharge laser system has been developed and applied to optically pumping the bound {r_arrow} free XeF ({ital C}{r_arrow}{ital A}) transition that lases in the blue-green (475--490-nm) and the {ital P}{sub 1/2}2{r_arrow}{ital P}{sub 3/2}2 transition of atomic iodine at 1.315 {mu}m. Employing no high voltage or current switches and occupying only {similar_to}1 m{sup 2} of table space, this device has an active length of {similar_to}50 cm and at present dissipates {gt}8 MW/cm of surface discharge for a stored energy of 2.5 kJ. With 5% output coupling at 485 nm, energies of {gt}50 mJ are obtained on the XeF ({ital C}{r_arrow}{ital A}) transition in 1.5-{mu}s (FWHM) pulses. The spectrum of the untuned oscillator is virtually free of absorption features and has a width of {similar_to}15 nm (FWHM). Pulse energies exceeding 0.7 J have been obtained for iodine at 1.3 {mu}m with an output coupling of only 10%.

Knecht, B.A.; Fraser, R.D.; Wheeler, D.J.; Zietkiewicz, C.J. [Everitt Laboratory, Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Mikheev, L.D.; Zuev, V.S. [P. N. Lebedev Physical Institute, Moscow, Russian Federation (??); Eden, J.G. [Everitt Laboratory, Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801 (United States)

1995-05-01

433

Role of N2 molecules in pulse discharge production of I atoms for a pulsed chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A pulsed electric discharge is the most effective means to turn chemical oxygen-iodine laser (COIL) operation into the pulse mode by fast production of iodine atoms. Experimental studies and numerical simulations are performed on a pulsed COIL initiated by an electric discharge in a mixture CF3I : N2 : O2(3X) : O2(a 1?g) flowing out of a chemical singlet oxygen generator. A transverse pulsed discharge is realized at various iodide pressures. The model comprises a system of kinetic equations for neutral and charged species, the electric circuit equation, the gas thermal balance equation and the photon balance equation. Reaction rate coefficients for processes involving electrons are repeatedly re-calculated by the electron Boltzmann equation solver when the plasma parameters are changed. The processes accounted for in the Boltzmann equation include direct and stepwise excitation and ionization of atoms and molecules, dissociation of molecules, electron attachment processes, electron-ion recombination, electron-electron collisions and second-kind collisions. The last processes are particularly important because of a high singlet oxygen concentration in gas flow from the singlet oxygen chemical generator. A conclusion is drawn about satisfactory agreement between the theory and the experiment.

Kochetov, I. V.; Napartovich, A. P.; Vagin, N. P.; Yuryshev, N. N.

2011-09-01

434

Laser power transmission  

NASA Technical Reports Server (NTRS)

An overview of previous studies related to laser power transmission is presented. Particular attention is given to the use of solar pumped lasers for space power applications. Three general laser mechanisms are addressed: photodissociation lasing driven by sunlight, photoexcitation lasing driven directly by sunlight, and photoexcitation lasing driven by thermal radiation.

Conway, Edmund J.

1992-01-01

435

Hydrogen pumped iodine laser study. Final report May 1976September 1979  

Microsoft Academic Search

Experimental data relative to attempts to induce lasing at 1.3154 microns in a chemical atomic iodine medium are presented. The critical issue was the establishment of high number densities of hydrogen atoms. First, atomic hydrogen was prepared by shock-heating mixtures of H2 in Ar. The plenum gases were accelerated through a nozzle bank and molecular HI was injected into the

J. A. Blauer; J. W. Raymonda; D. R. Janiak; G. D. Hager; R. Shortridge

1980-01-01

436

High average power, rare-gas halogen-pumped iodine laser for fusion applications  

Microsoft Academic Search

The rare-gas halogen and diatomic halogen molecular gases are relatively efficient, narrowband radiators in the ultraviolet spectral region when excited by electron beams. We have recently demonstrated production of 1.315 micron stimulated emission in atomic iodine by photolyzing C3F7I vapor with fluorescence emission from the XeBr exciplex. The use of spontaneous and superfluorescent emission from selected rare gas halogen exciplex

W. F. Krupke; E. V. George

1976-01-01

437

Development of a mist singlet oxygen generator for a chemical oxygen-iodine laser  

Microsoft Academic Search

Mist singlet oxygen generator (Mist-SOG) has been developed in order to increase the BHP utilization. On the other hand, Mist-SOG generates much more water vapor than conventional SOG because the heat capacity of the BHP is small. It is well known that the water vapor deactivates the excited iodine. In order to remove the water vapor, we developed a jet-cold

Shigeki Muto; Masamori Endo; Kenzo Nanri; Tomoo Fujioka

2003-01-01

438

O2(1Delta) production and gain in plasma pumped oxygen iodine lasers: consequences of NO and NO2 additives  

Microsoft Academic Search

The 1.315 µm [I(2P1\\/2) --> I(2P3\\/2)] transition of atomic iodine in the chemical oxygen-iodine laser (COIL) is pumped by sequential reactions of I2 and I with O2(1Delta). In electrically pumped systems (eCOILs), electron impact excitation of O2 produces the O2(1Delta) and also produces O atoms through dissociative excitation. The O atoms, through reactions with I2, I(2P1\\/2) and I(2P3\\/2), lead to

Ramesh A. Arakoni; Natalia Y. Babaeva; Mark J. Kushner

2007-01-01

439

O2(1?) production and gain in plasma pumped oxygen–iodine lasers: consequences of NO and NO2 additives  

Microsoft Academic Search

The 1.315 µm [I(2P1\\/2) ? I(2P3\\/2)] transition of atomic iodine in the chemical oxygen–iodine laser (COIL) is pumped by sequential reactions of I2 and I with O2(1?). In electrically pumped systems (eCOILs), electron impact excitation of O2 produces the O2(1?) and also produces O atoms through dissociative excitation. The O atoms, through reactions with I2, I(2P1\\/2) and I(2P3\\/2), lead to

Ramesh A Arakoni; Natalia Y Babaeva; Mark J Kushner

2007-01-01

440

Iodine poisoning  

MedlinePLUS

Iodine is a naturally occurring chemical. Small amounts are needed for good health. However, large doses can ... Children are especially sensitive to the effects of iodine. NOTE: Iodine is found in certain foods. However, ...

441

New Developments of a Laser-Induced Fluorescence Ground-Based Instrument for Measurements of Atmospheric Iodine Monoxide (IO)  

NASA Astrophysics Data System (ADS)

Iodine monoxide (IO) plays a role in the photochemistry of the marine boundary layer and potentially acts as a catalyst to ozone loss in the stratosphere. The distribution of IO in vertical, horizontal, and temporal coordinates is unknown, severely limiting the understanding of the impact of IO on global photochemistry. To better understand the role IO plays in the atmosphere, additional measurements of IO are required. High sensitivity in situ measurements are required to detect IO because it is present at low mixing ratios (<10 ppt) and is spatially and temporally inhomogeneous. A laser-induced fluorescence instrument centered around a nanosecond Nd:YAG-pumped Ti:Sapphire laser system has been built to satisfy these requirements. Highly efficient fluorescence detection optics and photon counting techniques have yielded sensitivities of better than 0.1 ppt in 1 s for IO in the laboratory. Recent work has been focused on improvements to sensitivity, mechanical design, and data acquisition following an initial field deployment of a prototype instrument. New developments including an optical redesign of both the laser and detection systems as well as the design of a fully automated, ground-based instrument are presented.

O'Brien, A.; Thurlow, M. E.; Co, D. T.; Hanisco, T. F.; Lapson, L. B.; Anderson, J.

2009-12-01

442

Zeeman effects in the hyperfine structure of atomic iodine photodissociation laser emission.  

NASA Technical Reports Server (NTRS)

Observation of hyperfine structure in laser emission from CF3I and C2F5I photodissociation lasers. Constant magnetic fields affect the time behavior of the emission by changing the relative gains of the hyperfine transitions. Time-varying fields usually present in photodissociation lasers further complicate the emission.

Hwang, W. C.; Kasper, J. V. V.

1972-01-01

443

Three-block model of the kinetics of vibrationally excited I{sub 2}(X) molecules in the active media of oxygen - iodine lasers  

SciTech Connect

A three-block model of the kinetics of vibrationally excited I{sub 2}(X) molecules in the active media of chemical oxygen - iodine lasers is developed. Instead of the system of equations describing a change in the concentrations of I{sub 2}(X, u) (u=0 - 47) molecules, this model uses equations for the total concentrations of iodine molecules belonging to the blocks of vibrational levels with u {<=} 10, u = 11 - 24, and u {>=} 25. Effective deactivation rate constants of I{sub 2}(X, 11 {<=} u {<=} 24) molecules are found for laser media of different compositions. The results of calculations performed using the proposed model agree with experimental data and are close to the parameters calculated previously by using the total system of equations for populations of individual vibrational levels of I{sub 2}(X, u). (laser applications and other topics in quantum electronics)

Pichugin, S Yu [Samara Branch of the P.N. Lebedev Physical Institute, Russian Academy of Sciences, Samara (Russian Federation)

2012-09-30

444

Optical frequency standard based on a Nd:YAG laser stabilised by saturated absorption resonances in molecular iodine using second-harmonic radiation  

SciTech Connect

The results of studies devoted to the development of the optical frequency standard based on a diode-pumped 1064-nm single-frequency ring Nd:YAG laser with intracavity frequency doubling are presented. The laser frequency was stabilised by saturated absorption resonances in molecular iodine at the second-harmonic frequency of the laser (at 532 nm). The saturated absorption resonances were observed in an external luminescent cell. The relative long-term frequency stability achieved in experiments was {approx}6x10{sup -15}. The physical and technical factors affecting the long-term frequency stability and reproducibility are investigated. (optical metrology and quantum frequency standards)

Skvortsov, Mikhail N; Okhapkin, M V; Nevsky, A Yu; Bagaev, Sergei N [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2004-12-31

445

Analytic study of the chain dark decomposition reaction of iodides - atomic iodine donors - in the active medium of a pulsed chemical oxygen-iodine laser: 1. Criteria for the development of the branching chain dark decomposition reaction of iodides  

SciTech Connect

The scheme of chemical processes proceeding in the active medium of a pulsed chemical oxygen-iodine laser (COIL) is analysed. Based on the analysis performed, the complete system of differential equations corresponding to this scheme is replaced by a simplified system of equations describing in dimensionless variables the chain dark decomposition of iodides - atomic iodine donors, in the COIL active medium. The procedure solving this system is described, the basic parameters determining the development of the chain reaction are found and its specific time intervals are determined. The initial stage of the reaction is analysed and criteria for the development of the branching chain decomposition reaction of iodide in the COIL active medium are determined. (active media)

Andreeva, Tamara L; Kuznetsova, S V; Maslov, Aleksandr I; Sorokin, Vadim N [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2009-02-28

446

Hydrogen pumped iodine laser study. Final report May 1976-September 1979  

SciTech Connect

Experimental data relative to attempts to induce lasing at 1.3154 microns in a chemical atomic iodine medium are presented. The critical issue was the establishment of high number densities of hydrogen atoms. First, atomic hydrogen was prepared by shock-heating mixtures of H2 in Ar. The plenum gases were accelerated through a nozzle bank and molecular HI was injected into the flow. Medium diagnostics were conducted in a windowed section downstream of the nozzle exit plane, on both 3 in. and 12 in. nozzle arrays. All attempts employing the shock tube to induce lasing in this chemical system were unsuccessful and measurements of small signal gain yielded ambiguous results. The major problem was probably loss of hydrogen atoms by wall recombustion. Following this, a CW approach for the in-situ chemical formation of atomic hydrogen involving reaction between sodium vapor and HI was tested in a flow reactor. Double-resonance gain measurements indicated loss rather than gain. Shock-tube experiments using conditions that previously yielded gain were repeated using the double-resonance gain diagnostic, and only loss was found. On the basis of these experimental results, it is recommended that efforts to obtain lasing from a hydrogen pumped iodine medium be discontinued.

Blauer, J.A.; Raymonda, J.W.; Janiak, D.R.; Hager, G.D.; Shortridge, R.

1980-07-01

447

Detection of vibrationally excited O{sub 2} in the active medium of a chemical oxygen - iodine laser  

SciTech Connect

The presence of vibrationally excited oxygen in the active medium of a chemical oxygen - iodine laser is discovered using the emission technique. Using the analysis of the luminescence spectra of oxygen molecules on O{sub 2}(b{sup 1{Sigma}}{sub g}{sup +}, v=i){yields}O{sub 2}(X{sup 3{Sigma}}{sub g}{sup -}, v'=i) (i=0, 1, 2) electronic vibrational - rotational transitions, it is shown that {approx}22 % of O{sub 2}(b{sup 1{Sigma}}{sub g}{sup +}) molecules are at the first vibrational level and {approx}10 % are at the second one. Moreover, due to the fast EE energy exchange, a mean number of vibrational quanta per one molecule in each of the O{sub 2}(X{sup 3{Sigma}}{sub g}{sup -}), O{sub 2}(a{sup 1{Delta}}{sub g}) and O{sub 2}(b{sup 1{Sigma}}{sub g}{sup +}) components is approximately the same and amounts to 30 % - 40 %. (active media. lasers)

Azyazov, V N; Antonov, I O; Pichugin, S Yu; Safonov, V S; Svistun, M I; Ufimtsev, N I [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2003-09-30

448

Effect of intense background radiation on the sensitivity of a laser receiver with an iodine active quantum filter  

SciTech Connect

The effect of background light on the sensitivity of a laser receiver with an iodine active quantum filter ({lambda}=1.315 {mu}m) was theoretically and experimentally investigated. Upon the reception of a 40-ns pulsed signal against the background of 2.5-fold attenuated radiation of a pulsed light source with a brightness temperature of 4 x 10{sup 4} K, the sensitivity of this receiver for a signal-to-noise ratio of three and a diffraction-limited acceptance angle was experimentally shown to be equal to 20 photons, which exceeds the quantum limit by about a factor of two. This is consistent with the results of theoretical treatment and suggests that upon the detection of optical signals against the background of the solar disk, the sensitivity of this receiver should decrease by only 12%. This receiver was compared with a receiver employing a photomultiplier of the visible range. Upon the reception of optical signals with the same parameters against the background of the solar disk and an interference filter with a transmission band width of 5 nm, the sensitivity of a receiver equipped with an FEU-115 photomultiplier was shown to be equal to about 1400 photons for a signal-to-noise ratio of three. (laser applications and other topics in quantum electronics)

Kutaev, Yu F; Mankevich, S K ['Astrofizika' Research and Production Association (Russian Federation); Nosach, O Yu; Orlov, E P [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2002-04-30

449

Prototype of a Laser-Induced Fluorescence Ground-Based Instrument for the Measurement of Atmospheric Iodine Monoxide (IO)  

NASA Astrophysics Data System (ADS)

Iodine monoxide (IO) plays a role in the photochemistry of the marine boundary layer and potentially acts as a catalyst to ozone loss in the stratosphere. The distribution of IO in vertical, horizontal, and temporal coordinates is not well known, severely limiting the understanding of the impact of IO on global photochemistry. Additional measurements of IO are necessary to develop a more comprehensive understanding of its extent and role in the atmosphere. High sensitivity in situ measurements are required to detect IO because it is present at low mixing ratios (<10 ppt) and is spatially and temporally inhomogeneous. A laser-induced fluorescence instrument centered around a nanosecond Nd:YAG-pumped Ti:Sapphire laser system has been built to satisfy these requirements. Highly efficient fluorescence detection optics and photon counting techniques have yielded sensitivities of better than 0.1 ppt in 1 minute for IO in the laboratory. Recent work has included the development of a compact, mobile, and environmentally-sealed architecture suitable for deploying the instrument in a variety of different environments. The instrument was deployed for validation to the Mace Head Atmospheric Research Station, National University of Ireland, during September of 2010. The instrumental design as well as preliminary results from the field deployment will be presented.

Thurlow, M. E.; O'Brien, A.; Co, D. T.; Hanisco, T. F.; Anderson, J.

2010-12-01

450

Advanced chemical lasers  

Microsoft Academic Search

A review of recent advances in chemical laser technology is presented. New technology and concepts related to the Chemical Oxygen Iodine Laser (COIL), All Gas-phase Iodine Laser (AGIL), and HF Overtone Laser are discussed.

Gerald C. Manke II; Kevin B. Hewett; Timothy J. Madden; John E. McCord; Charles F. Wisniewski; Gordon D. Hager

2004-01-01

451

Experimental study on an all gas-phase iodine laser using microwave discharge of Cl2/He as a Cl atoms source  

SciTech Connect

Microwave discharge of a Cl2/He mixture as a simple, clean and efficient Cl atom generator was used for an all gas-phase iodine laser study. Sufficient NCl(a1Delta) was produced through the reaction of HN3+2Cl {yields} NCl(a1Delta)+HCl+N2. The energy transfer reaction of I(2P3/2)+NCl(a1Delta) {yields} I(2P1/2)+NCl(X3Sigma) was observed. A population inversion was observed directly by using a 1315 nm tunable diode laser by scanning the entire line shape of the (3,4) hyperfine transition of iodine, and a small signal gain of 5x10-5 cm-1 was obtained.

Tang Shukai; Duo Liping; Jin Yuqi; Yu Haijun; Wang Jian; Sang Fengting

2006-09-20

452

Gain measurements in a non-self-sustained electric discharge pumped oxygen-iodine laser cavity  

NASA Astrophysics Data System (ADS)

The paper presents results of singlet delta oxygen yield (SDO) measurements in a high-pressure, non-self-sustained discharge and small signal gain measurements on the 1315 nm iodine atom transition in the M=3 supersonic cavity downstream of the discharge. The results demonstrate operation of a stable pulser-sustainer discharge in O II-He flows at pressures of up to 120 torr and discharge powers of up to 2.2 kW. The reduced electric field in the DC sustainer discharge ranges from 6 to 12 Td. SDO yield in the discharge is up to 5.0-5.7% at the discharge temperatures of 400-420 K. The results suggest that SDO yield exceeds the gain threshold yield at the M=3 cavity temperature by up to a factor of three, which is confirmed by gain measurements. The highest gain measured in the supersonic cavity is 0.01%/cm.

Hicks, A.; Fredrickson, K.; Tirupathi, S.; Utkin, Y. G.; Lempert, W. R.; Rich, J. W.; Adamovich, I. V.; Galbally-Kinney, K. L.; Kessler, W. J.; Rawlins, W. T.; Mulhall, P. A.; Davis, S. J.

2007-05-01

453

Investigation of an explosively pumped photo-dissociation iodine laser with phase conjugation of super-high quality  

NASA Astrophysics Data System (ADS)

Results of simulations and experiments on a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjugation (PC) are presented. The laser system consists of a master oscillator, two exploding amplifiers with a working mixture 25 Torr C3F7I+125 Torr Xe and amplifier aperture of 15 cm, and an SBS-mirror. The SBS mirror consists of an angular selector of Stokes radiation, an ordered raster of small diffraction lenses, a main focusing lens, and an SBS cell. The calculation model and the computer code package take into account the actual three-dimensionality of space, transient effects at SBS, parasitic reflections of laser radiation from elements of the optical scheme, intrinsic amplified spontaneous emission of amplifiers, radiation losses in the optical path, non-uniformity of gain, and radiation refraction on optical non-uniformities of the active medium caused by a shock wave. In the laser system, an optimal configuration of the SBS mirror is used. It possesses unique properties if compared to the existing specimens of SBS mirrors. It stably gives a nearly ideal quality of PC at any level of SBS saturation, i.e. any reflection coefficient that has been confirmed by experimental laboratory investigations. As a result of investigations, a good agreement of calculated results with available experimental data has been demonstrated in energy, time dependence of power and Strehl number of output radiation. The considered EPDL has output energy of about 400 J and brightness of about 1012 J/sr. It has been found that with the increase of the flux density of an input signal from the master oscillator in the range 0.01-20 W/cm2 the brightness of EPDL output radiation increases as well whereas the full energy varies relatively slightly. It has been shown that parasitic reflections of laser radiation from the ends of amplifiers and elements of the optical scheme with a coefficient exceeding 10-7 considerably decrease the axial brightness of output radiation. In order to reduce the harmful effect of parasitic reflections on brightness the distance between amplifiers should be increased.

Starikov, Fedor A.; Dolgopolov, Yu. V.; Dudov, A. M.; Gerasimenko, Natalia N.; Kirillov, Gennadi A.; Kochemasov, Gennady G.; Kopalkin, A. V.; Kovaldov, S. A.; Kulikov, Stanislav M.; Ladagin, Vladimir K.; Pevny, S. N.; Shkapa, A. F.; Smyshlyaev, Sergey P.; Sukharev, Stanislav A.; Zykov, L. I.

2004-06-01

454

Determination of singlet-oxygen generator efficiency on a 10kW class supersonic chemical oxygen-iodine laser (RADICL)  

Microsoft Academic Search

With the advent of the Air Force Airborne Laser program, the emphasis of chemical oxggen-iodine laser (COIL) research has shifted toward improving the overall efficiency. A key component of the COIL is the singlet-oxygen generator (SOG). To assess the efficiency of the SOG, an accurate method of determining the yield of O2(a1 ?g), [O2(a1?g )]\\/[O2(total)] where [O2(total)]=[O2 (a1?g)]+[O2(X3 ?g-)], has

Kip R. Kendrick; Charles A. Helms; Brian G. Quillen

1999-01-01

455

Deactivation rate of I{sub 2} molecules (X, v {>=} 30) in the medium of a chemical oxygen-iodine laser  

SciTech Connect

The effective deactivation rate constants are calculated for I{sub 2}(X) molecules at vibrational levels with v {>=} 30 colliding with N{sub 2} and O{sub 2} molecules in the medium of a chemical oxygen-iodine laser. The calculated constants (4x10{sup -12} cm{sup 3} s{sup -1} and 3x10{sup -12} cm{sup 3} s{sup -1}) are less by half plus than the corresponding constants found earlier in the paper of Lawrence et al., where the dissociation of I{sub 2} was neglected in calculations. (lasers, active media)

Pichugin, S Yu [Samara Branch of the P. N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation)

2008-08-31

456

INTERACTION OF LASER RADIATION WITH TARGETS Tomographic imaging of a target directly irradiated in experiments on the Iskra-5 iodine laser facility  

NASA Astrophysics Data System (ADS)

We set forth the data of experiments involving direct microtarget irradiation by the 12 second-harmonic beams (? = 0.66 ?m) of iodine laser radiation carried out on the Iskra-5 facility. For microtargets we employed glass shells ~500 ?m in diameter with ~1-?m thick walls, which were filled with a DT mixture at a pressure pDT approx 3-4 atm. In one of these experiments, a tomographic image of the microtarget was recorded from the images obtained using pinhole cameras, which were arranged along seven different directions. The pinhole images were acquired in the X-ray radiation with photon energies above 1.5 keV. The procedure used for reconstructing the volume luminosity of the microtarget is described. An analysis of the tomographic image suggests that the compressed microtarget domain possesses a complex asymmetric shape; 20-30 ?m sized structural elements being clearly visible. The resultant data set allowed us to estimate the initial nonuniformity of microtarget surface irradiation by the laser radiation. The rms nonuniformity of microtarget irradiance was estimated at ~60 %.

Bondarenko, S. V.; Garanin, R. V.; Garanin, Sergey G.; Zhidkov, N. V.; Oreshkov, O. V.; Potapov, S. V.; Suslov, N. A.; Frolova, N. V.

2010-12-01

457

Iodine monofluoride 140-kW laser: small signal gain and operating parameters.  

PubMed

Output energies in excess of 4 mJ in a ~30-nsec FWHM pulse (~140-kW peak power) have been obtained from a discharge-pumped IF laser for a cavity output coupling of 35%. In addition, oscillation on a new transition of the IF (E ? A) band at 472.7 nm has been observed. By measurement of the output power of the laser for various values of output mirror transmission, the small signal gain and loss coefficients were found to be (3.1 +/- 0.7)%-cm(-1) and ~0.3%-cm(-1), respectively. PMID:19701330

Dlabal, M L; Hutchison, S B; Eden, J G; Verdeyen, J T

1981-02-01

458

Iodine monofluoride 140-kW laser: small signal gain and operating parameters  

SciTech Connect

Output energies in excess of 4 mJ in a approx.30-nsec FWHM pulse (approx.140-kW peak power) have been obtained from a discharge-pumped IF laser for a cavity output coupling of 35%. In addition, oscillation on a new transition of the IF(E..-->..A) band at 472.7 nm has been observed. By measurement of the output power of the laser for various values of output mirror transmission, the small signal gain and loss coefficients were found to be (3.1 +- 0.7)%-cm/sup -1/ and approx.0.3%-cm/sup -1/, respectively.

Dlabal, M.L.; Hutchison, S.B.; Eden, J.G.; Verdeyen, J.T.

1981-02-01

459

Iodine monofluoride 140-kW laser - Small signal gain and operating parameters  

NASA Technical Reports Server (NTRS)

Output energies in excess of 4 mJ in a 30-nsec FWHM pulse (140-kW peak power) have been obtained from a discharge-pumped IF laser for a cavity output coupling of 35%. In addition, oscillation on a new transition of the IF (E-A) band at 472.7 nm has been observed. By measurement of the output power of the laser for various values of output mirror transmission, the small signal gain and loss coefficients were found to be (3.1 + or - 0.7)%/cm and 0.3%/cm, respectively.

Dlabal, M. L.; Hutchinson, S. B.; Eden, J. G.; Verdeyen, J. T.

1981-01-01

460

Chemistry of I(2P1/2) excitation in a hybrid catalytic electric-discharge oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The chemistry of electric discharge driven oxygen iodine lasers (EOIL) has long been believed to have O2(a1?g) as the sole energy carrier for excitation of the lasing state I(2P1/2), and O(3P) as the primary quencher of this state. In many sets of experimental measurements over a wide range of conditions, we have observed persistent evidence to the contrary. In this paper, we examine comparisons of kinetics analysis and model predictions to experimental results from a supersonic EOIL research reactor. This analysis leads to identification of important additional production and loss terms for the lasing species, I(2P1/2), in the EOIL reaction mechanism. These mechanisms are also relevant to the catalytically enhanced EOIL excitation mechanism. Exploitation of this chemistry can lead to substantial increases in gain and power extraction efficiency in larger-scale EOIL systems. The analysis points to a significantly higher level of understanding of this energetic chemical system, which can support application of advanced concepts in power scaling investigations.

Rawlins, Wilson T.; Lee, Seonkyung; Davis, Steven J.

2012-03-01

461

Extraction efficiency of a 5-cm gain length supersonic chemical oxygen-iodine laser  

Microsoft Academic Search

Gain saturation and diffractive loss data have been collected on the Phillips Laboratory's VertiCOIL laser. These data have been applied to the COIL simplified saturation model to estimate the optical extraction efficiency of VertiCOIL. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting

Charles A. Helms; Tilghman L. Rittenhouse; S. P. Phipps; Keith A. Truesdell; Gordon D. Hager

1997-01-01

462

Comparison of laser models  

NASA Technical Reports Server (NTRS)

The final phase of modeling solar pumped lasers considers the photodissociation of the perfloralkyl molecules n - C3F7I ,t - C4F9I, and i - C3F7I. Computer modeling was compared to laboratory data and good agreement between theory and experiment was achieved. The following is a summary of the modeling of solar pumped lasers. A perfloride gas enters a tube at a point z = 0 and travels a distance L at a velocity, W, and then exits at the point z = L. During the flow, the gas is solar pumped over the initial distance 0 less than or = z less than or = z sub 0, where z sub 0 is less than or equal to L. The perfloride gas interacts chemically with light and a chain of chemical reactions occur.

Heinbockel, John H.

1992-01-01

463

JOURNAL DE PHYSIQUE IV ColloqueC7,supplkmentau Journal de Physique 111,Vol. 1,dkmbre 1991  

E-print Network

of power laser beaming in spaceand its applicationsare presented. A direct solar-pumped iodine laser and the development of solar-pumped iodine laser systems as the space beam power transmitters will be presented. 2 LASER BEAMING AND APPLICATIONS IN SPACE Ja.H. LEE and E.J. CONWAY Mail Stop 493, Space Systems Divkion

Paris-Sud XI, Université de

464

Carrier phases for iodine in the Allende meteorite and their associated Xe-129(r)/I-127 ratios - A laser microprobe study  

NASA Technical Reports Server (NTRS)

This paper presents the results of a study of the carrier phases of iodine in the Allende meteorite and their associated Xe-129(r)/I-127 ratios, obtained using a new high-sensitivity low-blank mass spectrometer coupled with a low-blank laser extraction system. Two types of experiments were performed: a survey of the Xe-129(r) amounts in unirradiated specimens of fine-grained assemblages and individual coarse mineral grains, and a study of the relationship between chlorine and iodine in irradiated samples of the inclusions, in which the Xe-129(r)/I-127 ratios were determined for various minerals. As a by-product of these measurements, the Ar-40/Ar-39 ages were obtained along with some results on trapped Xe components. A schematic diagram of the new mass spectrometer system is included.

Kirschbaum, C.

1988-01-01

465

High-frequency-stability diode-pumped Nd:YAG lasers with the FM sidebands method and Doppler-free iodine lines at 532 nm.  

PubMed

The FM spectroscopy technique has been applied to two frequency-doubled Nd:YAG lasers to achieve absolute frequency stabilization against the hyperfine structure components of the rovibronic P(54) 32-0 iodine line at 532 nm. A fractional frequency stability of 2 x 10(-13) tau(-1/2) has been obtained for integration times in the range of 1 ms < tau < 10 s. For longer integration times the stability level remains below 10(-13), reaching a minimum value of 4.6 x 10(-14) at 100 s. This high stability level is, to our knowledge, the best value achieved against iodine lines by this locking method and for a fully transportable system. PMID:18324239

Galzerano, G; Svelto, C; Bava, E; Bertinetto, F

1999-11-20

466

Kinetic-fluid dynamics modeling of I{sub 2} dissociation in supersonic chemical oxygen-iodine lasers  

SciTech Connect

The mechanism of I{sub 2} dissociation in supersonic chemical oxygen-iodine lasers (COILs) is studied applying kinetic-fluid dynamics modeling, where pathways involving the excited species I{sub 2}(X {sup 1}SIGMA{sub g}{sup +},10<=v<25), I{sub 2}(X {sup 1}SIGMA{sub g}{sup +},25<=v<=47), I{sub 2}(A{sup '} {sup 3}PI{sub 2u}), I{sub 2}(A {sup 3}PI{sub 1u}), O{sub 2}(X {sup 3}SIGMA{sub g}{sup -},v), O{sub 2}(a {sup 1}DELTA{sub g},v), O{sub 2}(b {sup 1}SIGMA{sub g}{sup +},v), and I({sup 2}P{sub 1/2}) as intermediate reactants are included. The gist of the model is adding the first reactant and reducing the contribution of the second as compared to previous models. These changes, recently suggested by Azyazov, et al. [J. Chem. Phys. 130, 104306 (2009)], significantly improve the agreement with the measurements of the gain in a low pressure supersonic COIL for all I{sub 2} flow rates that have been tested in the experiments. In particular, the lack of agreement for high I{sub 2} flow rates, which was encountered in previous models, has been eliminated in the present model. It is suggested that future modeling of the COIL operation should take into account the proposed contribution of the above mentioned reactants.

Waichman, K. [Department of Physics, NRCN, P.O. Box 9001, Beer Sheva 89140 (Israel); Barmashenko, B. D.; Rosenwaks, S. [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel)

2009-09-15

467

Design investigation of solar powered lasers for space applications  

NASA Technical Reports Server (NTRS)

The feasibility of solar powered lasers for continuous operation in space power transmission was investigated. Laser power transmission in space over distances of 10 to 100 thousand kilometers appears possible. A variety of lasers was considered, including solar-powered GDLs and EDLs, and solar-pumped lasers. An indirect solar-pumped laser was investigated which uses a solar-heated black body cavity to pump the lasant. Efficiencies in the range of 10 to 20 percent are projected for these indirect optically pumped lasers.

Taussig, R.; Bruzzone, C.; Quimby, D.; Nelson, L.; Christiansen, W.; Neice, S.; Cassady, P.; Pindroh, A.

1979-01-01

468

Generation of iodine L-shell X-rays under excitation of large CF3I clusters by femtosecond laser radiation  

NASA Astrophysics Data System (ADS)

The use of clusters of polyatomic molecules with a relatively low ionisation energy (~10 eV) is proposed for the efficient production of X-ray radiation. We have observed for the first time the generation of characteristic X-ray radiation due to L transitions in iodine atoms under the high-intensity femtosecond laser irradiation of molecular CF3I clusters, which were a small admixture to Ar carrier gas. The X-ray conversion efficiency amounts to ~10-6 (for a yield of ~107 photons per pulse), which is an order of magnitude higher than the efficiency we obtained in the case of argon clusters under comparable conditions.

Gordienko, Vyacheslav M.; Dzhidzhoev, M. S.; Zhvaniya, I. A.; Pribytkov, Andrei V.; Trubnikov, Dmitrii N.; Fedorov, D. O.

2012-11-01

469

Gain and continuous-wave laser oscillation on the 1315 nm atomic iodine transition pumped by an air-helium electric discharge  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of gain and a continuous-wave laser on the 1315nm transition of atomic iodine using the energy transferred to I(P1/22) from O2(a?1) produced by a radio-frequency-excited electric discharge sustained in a dry air-He-NO gas mixture. Active oxygen and nitrogen species were observed downstream of the discharge region. Downstream of the discharge, cold gas injection was employed to raise the gas density and lower the temperature of the continuous gas flow. Gain of 0.0062%cm-1 was obtained and the laser output power was 32mW in a supersonic flow cavity.

Woodard, B. S.; Zimmerman, J. W.; Benavides, G. F.; Carroll, D. L.; Verdeyen, J. T.; Palla, A. D.; Field, T. H.; Solomon, W. C.; Davis, S. J.; Rawlins, W. T.; Lee, S.

2008-07-01

470

Effect of the solution temperature in a singlet-oxygen generator on the formation of active medium in an ejector oxygen - iodine laser  

SciTech Connect

The influence of the solution temperature in a singlet-oxygen generator on the formation of the active medium in the ejector oxygen - iodine laser is investigated. The following parameters of the active medium at the solution temperature -20{sup 0}C are obtained: the gain is 7.2 x 10{sup -3} cm{sup -1}, the Mach number is M=2, the temperature is 205 K, and the static pressure is 9.3 mmHg. As the solution temperature is increased to -4{sup 0}C, the gain decreases to 5 x 10{sup 3} cm{sup -1}, the Mach number decreases to 1.78, while the temperature and the static pressure increase to 241 K and 10.7 mmHg, respectively. As the solution temperature increases from -20 to -4{sup 0}C, the losses in O{sub 2}({sup 1}{Delta}) increase by less than 20%, while the dissociation efficiency of molecular iodine decreases by less than 21%. (lasers, active media)

Zagidullin, M V; Nikolaev, V D; Svistun, M I; Khvatov, N A [Samara Branch of the P.N. Lebedev Physics Institute, Russian Academy of Sciences, Samara (Russian Federation); Palina, N Yu [Samara State University, Samara (Russian Federation)

2002-02-28

471

Quantum-well lasers for direct solar photopumping  

NASA Technical Reports Server (NTRS)

Semiconductor lasers directly photopumped by focused sunlight may be viable sources of coherent light for intersatellite communications and other low-power spaceborne applications. In this work, we theoretically explore the possibility of realizing such devices. We specifically assess solar pumped operation of separate-confinement-quantum-well heterostructure (SCQWH) lasers based on InGaAs, GaAs, and AlGaA, as fabrication technology for these lasers is mature and they can operate at very low thresholds. We develop a model for step-index single-well SCQWH lasers photopumped by sunlight, examine how threshold solar photoexcitation intensities depend upon material and structure parameters, design optimum structures for solar-pumped operation, and identify design tradeoffs. Our results suggest that laser action