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Sample records for passively q-switched mode-locking

  1. Five simultaneously Q-switch mode-locked passive laser modulators

    NASA Astrophysics Data System (ADS)

    Chen, Junewen

    2007-02-01

    Five types of passive Q-switched as well as simultaneously Q-switch mode-locked modulators: plastic dye sheets ( Kodak 9850 cellulose acetate dye sheets), lithium fluoride crystals containing F II - color centers ( LiF: F II -), chromium doped yttrium aluminum garnet crystals ( Cr 4+:YAG), ionic color filter glass ( Schott RG1000 color filter glass) and the single crystal semiconductor wafers ( GaAs, Fe doped InP, Zn doped InP, S doped InP, etc.) used for the modulation of the Nd:hosted(Nd:YAG, Nd:YVO 4, and Nd:LSB) lasers have been investigated in detail in our researches. We have also investigated into the applications of the Q-switch mode-locked pulses train for the development of higher resolution solid state laser range finder. We will also present the high accuracy laser ranging results, the micro-motor that driven mechanical parts from the stepping digital ranging readout, to precisely control the best focus of a miniature zoom lens modular. The core simultaneously Q-switch mode-locked modulators microchip laser is the key part of our automatic optical inspection system.

  2. All-solid-state passively Q -switched mode-locked Nd-doped fiber laser

    SciTech Connect

    Zenteno, L.A.; Po, H.; Cho, N.M. )

    1990-01-15

    We report the generation of {ital Q}-switched mode-locked pulses from a Nd-doped fiber laser that uses a solid-state solution of BDN-I dye as the saturable absorber and is pumped by a GaAlAs laser diode. For an absorbed pump power of 110 m W, pulses of 8-nsec duration at a repetition rate of 14 MHz can be generated under an 800-nsec-wide {ital Q}-switched envelope at a repetition rate of 100 kHz, yielding an average output power of 8 m W near 1.06 {mu}m. This corresponds to approximately 9 W of peak power in the main mode-locked pulse.

  3. Passively Q-switched and mode-locked dual-wavelength Nd:GGG laser with Cr4+:YAG as a saturable absorber

    NASA Astrophysics Data System (ADS)

    Chu, Hongwei; Zhao, Shengzhi; Li, Yufei; Yang, Kejian; Li, Guiqiu; Li, Dechun; Zhao, Jia; Qiao, Wenchao; Li, Tao; Feng, Chuansheng; Zhang, Haijuan

    2014-03-01

    By using neodymium-doped gadolinium gallium garnet (Nd:GGG) as a laser medium, a simultaneously passively Q-switched and mode-locked (QML) dual-wavelength laser with Cr4+:YAG as a saturable absorber is presented. The laser simultaneously oscillated at 1061 nm and 1063 nm, corresponding to a frequency difference of 0.53 THz. QML pulses with nearly 100% modulation depth were observed. The mode-locked pulse duration underneath the Q-switched envelope was estimated to be about 908 ps. The experimental results indicated that the dual-wavelength QML Nd:GGG laser can be an excellent candidate for the generation of THz waves.

  4. As-grown uniform MoS2/mica saturable absorber for passively Q-switched mode-locked Nd:GdVO4 laser

    NASA Astrophysics Data System (ADS)

    Xu, Yuanyuan; Yang, Cheng; Ge, Pengguang; Liu, Jie; Jiang, Shouzhen; Li, Chun; Man, Baoyuan

    2016-08-01

    Molybdenum disulfide (MoS2) has recently attracted growing attention due to its distinctive properties and potential applications in optoelectronics and electronics. Here, large-area and high-quality MoS2 film with uniform thickness was obtained by thermally decomposing ammonium thiomolybdate. Besides, it is firstly demonstrated that the as-grown MoS2/mica can be directly inserted into Nd:GdVO4 laser cavity as saturable absorber for the output of diode-pumped passively Q-switched mode-locked pulse trains. Using the MoS2 saturable absorbers, the stable Q-switched mode-locked pulse trains with high modulation depth were realized, suggesting that the broadband MoS2 SA could potentially be employed in mode-locking laser system

  5. Passively Q-switched mode locking in a compact Nd:GdVO4/Cr:YAG self-Raman laser

    NASA Astrophysics Data System (ADS)

    Peng, Jiying; Zheng, Yi; Zheng, Kai; Chang, Xiaowei

    2012-11-01

    Passively Q-switched mode locking in a compact Nd:GdVO4 self-Raman laser with a Cr:YAG saturable absorber was demonstrated. The picosecond first stokes at 1173 nm was successfully obtained. When the optical cavity length changed from 167 mm to 120 mm, the mode-locked pulse repetition rate increased from 0.9 GHz to 1.25 GHz. At the maximum diode pump power of 10 W and with a pulse repetition rate of 0.9 GHz, an average output power up to 105 mW has been achieved at 1173 nm. In addition, the yellow laser output at 586.5 nm was also realized by frequency doubling with an LBO crystal.

  6. Doubly active Q switching and mode locking of an all-fiber laser.

    PubMed

    Cuadrado-Laborde, Christian; Díez, Antonio; Cruz, Jose L; Andrés, Miguel V

    2009-09-15

    Simultaneous and independent active Q switching and active mode locking of an erbium-doped fiber laser is demonstrated using all-fiber modulation techniques. A magnetostrictive rod attached to the output fiber Bragg grating modulates the Q factor of the Fabry-Perot cavity, whereas active mode locking is achieved by amplitude modulation with a Bragg-grating-based acousto-optic device. Fully modulated Q-switched mode-locked trains of optical pulses were obtained for a wide range of pump powers and repetition rates. For a Q-switched repetition rate of 500 Hz and a pump power of 100 mW, the laser generates trains of 12-14 mode-locked pulses of about 1 ns each, within an envelope of 550 ns, an overall energy of 0.65 microJ, and a peak power higher than 250 W for the central pulses of the train. PMID:19756079

  7. Q-switched and mode-locked Er{sup 3+}-doped fibre laser using a single-multi-single fibre filter and piezoelectric

    SciTech Connect

    Ji Wang; Yunjun Zhang; Aotuo Dong; Xiaoxin Xu; Youlun Ju; Baoquan Yao

    2014-04-28

    The active Q-switched and passive mode-locked Er{sup 3+}-doped all-fibre laser is presented. The fibre laser centre wavelength is located at 1563 nm and determined by the homemade singlemulti- single (SMS) in-line fibre filter. The laser spectrum width is nearly 0.1 nm. The active Q-switched mechanism relies on the polarisation state control using a piezoelectric to press a segment of passive fibre on the circular cavity. The nonlinear polarisation rotation technology is used to realise the passive self-started modelocked operation. In the passive mode-locked regimes, the output average power is 2.1 mW, repetition frequency is 11.96 MHz, and single pulse energy is 0.18 nJ. With the 100-Hz Q-switched regimes running, the output average power is 1.5 mW. The total Q-switched pulse width is 15 μs, and every Q-switched pulse is made up by several tens of mode-locked peak pulses. The calculated output pulse energy of the Q-switched fibre laser is about 15 μJ, and the energy of every mode-locked pulse is about 64–68 nJ during a Q-switched pulse taking into account the power fraction propagating between pulses. (lasers)

  8. Q-switched and mode-locked Er3+-doped fibre laser using a single-multi-single fibre filter and piezoelectric

    NASA Astrophysics Data System (ADS)

    Wang, Ji; Zhang, Yunjun; Dong, Aotuo; Xu, Xiaoxin; Ju, Youlun; Yao, Baoquan

    2014-04-01

    The active Q-switched and passive mode-locked Er3+-doped all-fibre laser is presented. The fibre laser centre wavelength is located at 1563 nm and determined by the homemade singlemulti- single (SMS) in-line fibre filter. The laser spectrum width is nearly 0.1 nm. The active Q-switched mechanism relies on the polarisation state control using a piezoelectric to press a segment of passive fibre on the circular cavity. The nonlinear polarisation rotation technology is used to realise the passive self-started modelocked operation. In the passive mode-locked regimes, the output average power is 2.1 mW, repetition frequency is 11.96 MHz, and single pulse energy is 0.18 nJ. With the 100-Hz Q-switched regimes running, the output average power is 1.5 mW. The total Q-switched pulse width is 15 μs, and every Q-switched pulse is made up by several tens of mode-locked peak pulses. The calculated output pulse energy of the Q-switched fibre laser is about 15 μJ, and the energy of every mode-locked pulse is about 64-68 nJ during a Q-switched pulse taking into account the power fraction propagating between pulses.

  9. Diode pumped Nd:YAG laser with active Q-switching and mode locking for hole drilling

    NASA Astrophysics Data System (ADS)

    Solokhin, S. A.; Sirotkin, A. A.; Garnov, S. V.

    2011-06-01

    A diode-pumped Nd:YAG laser operating with active-passive Q-switch mode locking, has been developed. The acousto-optic repetition train was one kilohertz with generated pulse train widths 65 ns, single pulse widths 200 ps and an average power of 6.5 W. Improvement of efficiency of small diameter deep holes laser drilling in different materials was studied.

  10. Active/passive mode-locked laser oscillator

    DOEpatents

    Fountain, William D.; Johnson, Bertram C.

    1977-01-01

    A Q-switched/mode-locked Nd:YAG laser oscillator employing simultaneous active (electro-optic) and passive (saturable absorber) loss modulation within the optical cavity is described. This "dual modulation" oscillator can produce transform-limited pulses of duration ranging from about 30 psec to about 5 nsec with greatly improved stability compared to other mode-locked systems. The pulses produced by this system lack intrapulse frequency or amplitude modulation, and hence are idealy suited for amplification to high energies and for other applications where well-defined pulses are required. Also, the pulses of this system have excellent interpulse characteristics, wherein the optical noise between the individual pulses of the pulse train has a power level well below the power of the peak pulse of the train.

  11. Q-switching and mode-locking in a diode-pumped frequency-doubled Nd : YAG laser

    SciTech Connect

    Donin, Valerii I; Yakovin, Dmitrii V; Gribanov, A V

    2012-02-28

    A new method for obtaining Q-switching simultaneously with mode-locking using one travelling-wave acousto-optic modulator in a frequency-doubled Nd : YAG laser cavity is described. Further shortening of output laser pulses (from 40 to 3.25 ps) is achieved by forming a Kerr lens in the frequency-doubling crystal. At an average power of {approx} 2 W and a Q-switching rate of 2 kHz, the peak power of the stably operating reached {approx} 50 MW.

  12. Q-switched mode-locked and azimuthally polarized Nd:GdVO4 laser with semiconductor saturable absorber mirror

    NASA Astrophysics Data System (ADS)

    Hong, Kun-Guei; Hung, Bi-Jin; Lin, Shih-Ting; Wei, Ming-Dar

    2016-06-01

    A Q-switched mode-locked Nd:GdVO4 laser with azimuthal polarization was generated using a semiconductor saturable absorber mirror. On the basis of the birefringence of the laser crystal inducing different equivalent lengths for ordinary and extraordinary rays, beams were azimuthally polarized around the edge of a stable cavity region. At a pump power of 9 W, the repetition rate and width for the Q-switched envelope were 318 kHz and 0.91 µs, and the mode-locked pulse repetition rate and pulse width were 455 MHz and 65 ps, respectively. The degree of polarization was controllable up to 95.4 ± 1.4%.

  13. An automatic mode-locked system for passively mode-locked fiber laser

    NASA Astrophysics Data System (ADS)

    Li, Sha; Xu, Jun; Chen, Guoliang; Mei, Li; Yi, Bo

    2013-12-01

    This paper designs and implements one kind of automatic mode-locked system. It can adjust a passively mode-locked fiber laser to keep steady mode-locked states automatically. So the unsteadiness of traditional passively mode-locked fiber laser can be avoided. The system transforms optical signals into electrical pulse signals and sends them into MCU after processing. MCU calculates the frequency of the signals and judges the state of the output based on a quick judgment algorithm. A high-speed comparator is used to check the signals and the comparison voltage can be adjusted to improve the measuring accuracy. Then by controlling two polarization controllers at an angle of 45degrees to each other, MCU extrudes the optical fibers to change the polarization until it gets proper mode-locked output. So the system can continuously monitor the output signal and get it back to mode-locked states quickly and automatically. States of the system can be displayed on the LCD and PC. The parameters of the steady mode-locked states can be stored into an EEPROM so that the system will get into mode-locked states immediately next time. Actual experiments showed that, for a 6.238MHz passively mode-locked fiber lasers, the system can get into steady mode-locked states automatically in less than 90s after starting the system. The expected lock time can be reduced to less than 20s after follow up improvements.

  14. Nanosecond pulses in a THz gyrotron oscillator operating in a mode-locked self-consistent Q-switch regime.

    PubMed

    Alberti, S; Braunmueller, F; Tran, T M; Genoud, J; Hogge, J-Ph; Tran, M Q; Ansermet, J-Ph

    2013-11-15

    An experimental study of a nanosecond pulsed regime in a THz gyrotron oscillator operating in a self-consistent Q-switch regime has been carried out. The gyrotron is operated in the TE(7,2) transverse mode radiating at a frequency of 260.5 GHz. The 5 W nanosecond pulses are obtained in a self-consistent Q-switch regime in which the cavity diffraction quality factor dynamically varies by nearly 2 orders of magnitude on a subnanosecond time scale via the nonlinear interaction of different mode-locked frequency-equidistant sidebands. The experimental results are in good agreement with numerical simulations performed with the TWANG code based on a slow time scale formulation of the self-consistent time-dependent nonlinear wave particle interaction equations. PMID:24289692

  15. Q-switched-like soliton bunches and noise-like pulses generation in a partially mode-locked fiber laser.

    PubMed

    Wang, Zhenhong; Wang, Zhi; Liu, Yan-Ge; Zhao, Wenjing; Zhang, Hao; Wang, Shangcheng; Yang, Guang; He, Ruijing

    2016-06-27

    We report an intermediate regime between c.w. emission and noise-like pulses (NLPs) regime in an Er-doped partially mode-locked fiber laser with nonlinear polarization rotation. In this regime, the soliton bunches stochastically turn up from a quasi-cw background in the Q-switched-like envelope. The soliton bunches normally last for tens or hundreds of intracavity round-trips. When the soliton bunches vanish, typical NLPs chains are generated sporadically at location where the soliton bunches collapses. These results would be helpful to understand the generation and property of the NLPs regime. PMID:27410624

  16. WS₂ as a saturable absorber for ultrafast photonic applications of mode-locked and Q-switched lasers.

    PubMed

    Wu, Kan; Zhang, Xiaoyan; Wang, Jun; Li, Xing; Chen, Jianping

    2015-05-01

    Two-dimensional (2D) nanomaterials, especially the transition metal sulfide semiconductors, have drawn great interests due to their potential applications in viable photonic and optoelectronic devices. In this work, 2D tungsten disulfide (WS2) based saturable absorber (SA) for ultrafast photonic applications was demonstrated. WS2 nanosheets were prepared using liquid-phase exfoliation method and embedded in polyvinyl alcohol (PVA) thin film for the practical usage. Saturable absorption was discovered in the WS2-PVA SA at the telecommunication wavelength near 1550 nm. By incorporating WS2-PVA SA into a fiber laser cavity, both stable mode locking operation and Q-switching operation were achieved. In the mode locking operation, the laser obtained femtosecond output pulse width and high spectral purity in the radio frequency spectrum. In the Q-switching operation, the laser had tunable repetition rate and output pulse energy of a few tens of nano joule. Our findings suggest that few-layer WS2 nanosheets embedded in PVA thin film are promising nonlinear optical materials for ultrafast photonic applications as a mode locker or Q-switcher. PMID:25969240

  17. Modulation frequency characteristics of the Q-switched envelope in a doubly Q-switched and mode-locked laser with acousto-optic modulator and Cr4+:YAG saturable absorber

    NASA Astrophysics Data System (ADS)

    Qiao, Junpeng; Zhao, Jia; Li, Yufei; Zhao, Shengzhi; Li, Guiqiu; Li, Dechun; Qiao, Wenchao; Chu, Hongwei

    2015-11-01

    The modulation frequency characteristics of the Q-switched envelope in a doubly Q-switched and mode-locked Nd:GGG laser with an acousto-optic modulator (AOM) and Cr4+:YAG saturable absorber are given. At a fixed incident pump power, the repetition rates of the Q-switched envelope and the related laser characteristics versus the modulation frequency of AOM for different small signal transmissions of Cr4+:YAG saturable absorbers have been measured. The experimental results show that the repetition rates of the Q-switched envelope, the average output power, the average peak power, and the pulse widths of the Q-switched envelopes are subharmonics of the modulation frequency at a fixed incident pump power. Furthermore, the mechanism for these behaviors is discussed.

  18. All fiber passively Q-switched laser

    DOEpatents

    Soh, Daniel B. S.; Bisson, Scott E

    2015-05-12

    Embodiments relate to an all fiber passively Q-switched laser. The laser includes a large core doped gain fiber having a first end. The large core doped gain fiber has a first core diameter. The laser includes a doped single mode fiber (saturable absorber) having a second core diameter that is smaller than the first core diameter. The laser includes a mode transformer positioned between a second end of the large core doped gain fiber and a first end of the single mode fiber. The mode transformer has a core diameter that transitions from the first core diameter to the second core diameter and filters out light modes not supported by the doped single mode fiber. The laser includes a laser cavity formed between a first reflector positioned adjacent the large core doped gain fiber and a second reflector positioned adjacent the doped single mode fiber.

  19. Cavity length dependence of mode beating in passively Q-switched Nd-solid state lasers

    NASA Astrophysics Data System (ADS)

    Zameroski, Nathan D.; Wanke, Michael; Bossert, David

    2013-03-01

    The temporal intensity profile of pulse(s) from passively Q-switched and passively Q-switched mode locked (QSML) solid-state lasers is known to be dependent on cavity length. In this work, the pulse width, modulation depth, and beat frequencies of a Nd:Cr:GSGG laser using a Cr+4:YAG passive Q-switch are investigated as function cavity length. Measured temporal widths are linearly correlated with cavity length but generally 3-5 ns larger than theoretical predictions. Some cavity lengths exhibit pulse profiles with no modulation while other lengths exhibit complete amplitude modulation. The observed beat frequencies at certain cavity lengths cannot be accounted for with passively QSML models in which the pulse train repetition rate is τRT-1, τRT= round-trip time. They can be explained, however, by including coupled cavity mode-locking effects. A theoretical model developed for a two section coupled cavity semiconductor laser is adapted to a solid-state laser to interpret measured beat frequencies. We also numerically evaluate the temporal criterion required to achieve temporally smooth Q-switched pulses, versus cavity length and pump rate. We show that in flash lamp pumped systems, the difference in buildup time between longitudinal modes is largely dependent on the pump rate. In applications where short pulse delay is important, the pumping rate may limit the ability to achieve temporally smooth pulses in passively Q-switched lasers. Simulations support trends in experimental data. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. BRIEF COMMUNICATIONS: Dye-jet laser pumped by the second harmonic of a Q-switched and mode-locked YAG:Nd3+ laser

    NASA Astrophysics Data System (ADS)

    Golubev, V. A.; Goncharov, A. N.; Maĭorov, A. P.; Makukha, V. K.; Smirnov, Vitalii A.; Tarasov, V. M.

    1981-05-01

    A report is given of the operating parameters of a dye jet laser pumped by the second harmonic of a cw Q-switched mode-locked YAG:Nd3+ laser. The dye laser emitted a continuous train of 250 nsec pulses at a repetition frequency of 25 kHz or a sequence of ultrashort pulse trains. A Lyot filter was used to tune the emission wavelength in the range 560-630 nm.

  1. Generation of Q-switched mode locking controlled rectangular noise-like soliton bunching in a Tm-doped fiber laser.

    PubMed

    Qiao, Tian; Chen, Weicheng; Lin, Wei; Yang, Zhongmin

    2016-08-01

    We report on an interesting phenomenon of the combination of Q-switched mode locked pulses (QSMLP) and rectangular noise-like pulses (RNLP) as a unit in a Tm-doped ring fiber laser which contains a Fabry-Perot (F-P) subcavity based on the nonlinear polarization evolution (NPE) technique. The RNLP and QSMLP are independently generated in the ring cavity and F-P subcavity, respectively. A notable characteristic is that the physical parameters of RNLP, e.g. repetition rate and pulse duration, are controlled by QSMLP. Thus, they form as a composite bunching, which is termed as "Q-switched mode locking controlled rectangular noise-like soliton bunching (QRNSB)". Further investigation shows that the existence of QRNSB only occurs in high pumping conditions, while both fundamental mode-locking pulses and the coexistence of QSMLP and solitons are achieved in low pumping ones. Our work can enrich the understanding of the nonlinear dynamics in fiber lasers. PMID:27505838

  2. Passive mode locking in erbium-ytterbium fiber lasers

    NASA Astrophysics Data System (ADS)

    Thai, Serey; Hayduk, Michael J.

    1999-11-01

    A novel mode-locked erbium-ytterbium fiber laser operating at 1550 nm using multiple quantum well (MQW) saturable absorbers was developed. The laser was constructed in a Fabry-Perot configuration using a fiber Bragg grating as a front reflector and a fiber Bragg grating output as a back reflector of the laser cavity. The passive mode-locking element placed inside the laser cavity is a 75 period InGaAs/InAlAs MQW saturable absorber grown lattice matched on an InP substrate. The output of the laser was taken through the other available port of a wavelength-division demultiplexer. The laser produced mode-locked output pulse trains at 16.67-MHz repetition rate and 10 mW of average output power.

  3. Self-organization of the Q-switched mode-locked regime in a diode-pumped Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Donin, V. I.; Yakovin, D. V.; Gribanov, A. V.

    2015-06-01

    A new Q-switched mode-locked generation regime of a solid-state laser, in which a Q-switch is "spontaneously" formed at the frequency of relaxation oscillations, has been observed for the first time. The new generation has been implemented by means of the previously proposed method of an acoustic modulator of a traveling wave in combination with a spherical mirror of a cavity. Stable pulse trains with a repetition frequency of ~30 kHz and a duration of ~2 µs have been observed in the diode-pump Nd:YAG laser with an average output power of ~3 W. Each train contains about 200 equispaced single pulses with a duration of ~45 ps.

  4. Passively mode-locked Yb:LuVO4 oscillator

    NASA Astrophysics Data System (ADS)

    Rivier, Simon; Mateos, Xavier; Liu, Junhai; Petrov, Valentin; Griebner, Uwe; Zorn, Martin; Weyers, Markus; Zhang, Huaijin; Wang, Jiyang; Jiang, Minhua

    2006-11-01

    Passive mode locking of the ytterbium doped orthovanadate crystal Yb:LuVO4 is reported for the first time. We demonstrate what we believe to be the shortest pulses directly generated with an Yb-doped crystalline laser using a semiconductor saturable absorber. The pulses at 1036 nm have a duration as short as 58 fs for an average power of 85 mW.

  5. Synchronization of active/passive mode-locked erbium fiber lasers

    NASA Astrophysics Data System (ADS)

    Kaechele, Walter; Haus, Joseph W.; Hayduk, Michael J.; Erdmann, Reinhard K.; Teegarden, Kenneth J.

    1997-07-01

    Injection seeding of a passively mode-locked fiber laser by an actively mode-locked fiber laser source is described. The passively mode-locked laser employs a multiple quantum well saturable absorber to establish pulsed operation. Mode-locked synchronized operation was maintained with average injection powers as low as 1.3 mW. Stable synchronized pulses were observed with pulse widths as narrow as 10 ps.

  6. cw passive mode locking of a Ti:sapphire laser

    SciTech Connect

    Sarukura, N.; Ishida, Y.; Nakano, H.; Yamamoto, Y. )

    1990-02-26

    cw passive mode locking of a Ti:sapphire laser is achieved with 1,1{prime}-dietyl-2,2{prime}-dicarbocyanine iodide as the saturable absorber dye, using a 5 {mu}m thin dye jet flow. The pulse width is 4.0 ps, which is almost the transform-limited pulse for the observed spectrum width. The output power is {similar to}50 mW, when it is pumped by a 5 W cw Ar laser, while the tuning range is 745--755 nm.

  7. Black phosphorus: a two-dimension saturable absorption material for mid-infrared Q-switched and mode-locked fiber lasers

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Luo, Hongyu; Zhai, Bo; Lu, Rongguo; Guo, Zhinan; Zhang, Han; Liu, Yong

    2016-07-01

    Black phosphorus (BP) as a novel class of two-dimension (2D) materials has recently attracted enormous attention as a result of its unique physical and chemical features. The remarkably strong light-matter interaction and tunable direct band-gap at a wide range make it an ideal candidate especially in the mid-infrared wavelength region as the saturable absorber (SA). In this paper, the simple and effective liquid phase exfoliation (LPE) method was used to fabricate BP. By introducing the same BP SA into two specifically designed rare earth ions doped fluoride fiber lasers at mid-infrared wavebands, Q-switching with the pulse energy of 4.93 μJ and mode-locking with the pulse duration of 8.6 ps were obtained, respectively. The operation wavelength of ~2970 nm for generated pulse is the reported longest wavelength for BP SA based fiber lasers.

  8. Black phosphorus: a two-dimension saturable absorption material for mid-infrared Q-switched and mode-locked fiber lasers

    PubMed Central

    Li, Jianfeng; Luo, Hongyu; Zhai, Bo; Lu, Rongguo; Guo, Zhinan; Zhang, Han; Liu, Yong

    2016-01-01

    Black phosphorus (BP) as a novel class of two-dimension (2D) materials has recently attracted enormous attention as a result of its unique physical and chemical features. The remarkably strong light-matter interaction and tunable direct band-gap at a wide range make it an ideal candidate especially in the mid-infrared wavelength region as the saturable absorber (SA). In this paper, the simple and effective liquid phase exfoliation (LPE) method was used to fabricate BP. By introducing the same BP SA into two specifically designed rare earth ions doped fluoride fiber lasers at mid-infrared wavebands, Q-switching with the pulse energy of 4.93 μJ and mode-locking with the pulse duration of 8.6 ps were obtained, respectively. The operation wavelength of ~2970 nm for generated pulse is the reported longest wavelength for BP SA based fiber lasers. PMID:27457338

  9. Black phosphorus: a two-dimension saturable absorption material for mid-infrared Q-switched and mode-locked fiber lasers.

    PubMed

    Li, Jianfeng; Luo, Hongyu; Zhai, Bo; Lu, Rongguo; Guo, Zhinan; Zhang, Han; Liu, Yong

    2016-01-01

    Black phosphorus (BP) as a novel class of two-dimension (2D) materials has recently attracted enormous attention as a result of its unique physical and chemical features. The remarkably strong light-matter interaction and tunable direct band-gap at a wide range make it an ideal candidate especially in the mid-infrared wavelength region as the saturable absorber (SA). In this paper, the simple and effective liquid phase exfoliation (LPE) method was used to fabricate BP. By introducing the same BP SA into two specifically designed rare earth ions doped fluoride fiber lasers at mid-infrared wavebands, Q-switching with the pulse energy of 4.93 μJ and mode-locking with the pulse duration of 8.6 ps were obtained, respectively. The operation wavelength of ~2970 nm for generated pulse is the reported longest wavelength for BP SA based fiber lasers. PMID:27457338

  10. Statistical light-mode dynamics of multipulse passive mode locking.

    PubMed

    Weill, Rafi; Well, Rafi; Vodonos, Boris; Gordon, Ariel; Gat, Omri; Fischer, Baruch

    2007-09-01

    We study the multipulse formation in passive mode locking in the framework of the statistical light-mode dynamics theory. It is a many-body theory that treats the complex many-mode laser system by statistical mechanics. We give a detailed theory and experimental verification for the important case of multiple-pulse formation in the laser cavity. We follow and extend our former work on the subject. We give a detailed analysis with a rigorous calculation of the partition function, the free energy, and the order parameter in the coarse-graining method within the mean-field theory that is exact in the light-mode system. The outcome is a comprehensive picture of multipulse formation and annihilation, pulse after pulse, in an almost quantized manner, as the noise ("temperature") or the light power is varied. We obtain the phase diagram of the system, showing a series of first-order phase transitions, each belonging to a different number of pulses. We also study the hysteresis behavior, typical for such thermodynamic systems. We elaborate on the role of the saturable absorber structure in determining the multipulse formation. The theoretical results are compared to experimental measurements that we obtained with mode-locked fiber lasers, and we find an excellent agreement. PMID:17930204

  11. A stable 2 μm passively Q-switched fiber laser based on nonlinear polarization evolution

    NASA Astrophysics Data System (ADS)

    He, X.; Luo, A.; Lin, W.; Yang, Q.; Yang, T.; Yuan, X.; Xu, S.; Xu, W.; Luo, Z.; Yang, Z.

    2014-08-01

    A passively Q-switched thulium-doped fiber (TDF) laser based on the nonlinear polarization evolution technique was demonstrated with the central wavelength of 1898.4 nm. With the increasing pump power, the pulse repetition frequency of the Q-switched TDF laser from 87.6 to 110.1 kHz was achieved, while the corresponding pulse duration was changed from 1171 to 785.7 ns. The power instability of the TDF laser was measured to be about ±1.5% during 8 h. In addition, the mode-locked phenomenon was also observed in our all-fiber TDF laser by carefully adjusting the polarization controllers.

  12. Passively mode-locked single-polarization microstructure fiber laser.

    PubMed

    Ortaç, B; Lecaplain, C; Hideur, A; Schreiber, T; Limpert, J; Tünnermann, A

    2008-02-01

    The generation of high-power and stable ultra-short pulses from a passively mode-locked purely normal dispersion fiber laser is reported using the unique combination of a photonic crystal fiber featuring single-polarization, single-mode, and low nonlinearity with a high modulation depth semiconductor saturable absorber mirror. The environmentally-stable, self-starting fiber laser generates 1.6 W of average power at a repetition rate of 63 MHz, corresponding to a pulse energy of 25 nJ. The emitted pulses are positively chirped with a pulse duration of 3.7 ps. They are compressible down to a near transform-limited duration of 750 fs. Numerical simulations are in good agreement with the experimental results. PMID:18542292

  13. Monolithic passively Q-switched Cr:Nd:GSGG microlaser

    NASA Astrophysics Data System (ADS)

    Schmitt, Randal L.

    2005-09-01

    Optical firing sets need miniature, robust, reliable pulsed laser sources for a variety of triggering functions. In many cases, these lasers must withstand high transient radiation environments. In this paper we describe a monolithic passively Q-switched microlaser constructed using Cr:Nd:GSGG as the gain material and Cr4+:YAG as the saturable absorber, both of which are radiation hard crystals. This laser consists of a 1-mm-long piece of undoped YAG, a 7-mm-long piece of Cr:Nd:GSGG, and a 1.5-mm-long piece of Cr4+:YAG diffusion bonded together. The ends of the assembly are polished flat and parallel and dielectric mirrors are coated directly on the ends to form a compact, rugged, monolithic laser. When end pumped with a diode laser emitting at ~807.6 nm, this passively Q-switched laser produces ~1.5-ns-wide pulses. While the unpumped flat-flat cavity is geometrically unstable, thermal lensing and gain guiding produce a stable cavity with a TEM00 gaussian output beam over a wide range of operating parameters. The output energy of the laser is scalable and dependent on the cross sectional area of the pump beam. This laser has produced Q-switched output energies from several μJ per pulse to several 100 μJ per pulse with excellent beam quality. Its short pulse length and good beam quality result in high peak power density required for many applications such as optically triggering sprytrons. In this paper we discuss the design, construction, and characterization of this monolithic laser as well as energy scaling of the laser up to several 100 μJ per pulse.

  14. Optical parametric oscillator of mid-IR, visible and UV ranges with synchronous pumping by a Q-switched mode-locked Nd : YAG laser

    NASA Astrophysics Data System (ADS)

    Donin, V. I.; Yakovin, M. D.; Yakovin, D. V.

    2016-07-01

    The parametric generation in a nonlinear PPLN crystal synchronously pumped by a Q-switched mode-locked Nd : YAG laser with a pulse duration of 45 ps is studied. The output pump intensity in the nonlinear crystal reaches ~10 GW cm-2. At a pulse repetition rate of 1 kHz, the average output power at the idler wavelength (~3.6 μm) is ~12 mW, the peak power is ~25 kW, and the conversion efficiency (with respect to the absorbed power) is ~10%. The radiation linewidth at the signal wavelength (~1.5 μm) is 13 cm-1. Along with the signal and idler waves, the output emission spectrum contains lines at wavelengths of 822, 754, 624, 532, 463, 442, 392 and 355 nm. The tunable radiation with wavelengths in the vicinity of 392, 463 and 822 nm is observed for the first time. The tuning ranges for the new lines are measured (5 – 10 nm) and their origin is explained.

  15. Passively Q-switched side pumped monolithic ring laser

    NASA Technical Reports Server (NTRS)

    Li, Steven X. (Inventor)

    2012-01-01

    Disclosed herein are systems and methods for generating a side-pumped passively Q-switched non-planar ring oscillator. The method introduces a laser into a cavity of a crystal, the cavity having a round-trip path formed by a reflection at a dielectrically coated front surface, a first internal reflection at a first side surface of the crystal at a non-orthogonal angle with the front, a second internal reflection at a top surface of the crystal, and a third internal reflection at a second side surface of the crystal at a non-orthogonal angle with the front. The method side pumps the laser at the top or bottom surface with a side pump diode array beam and generates an output laser emanating at a location on the front surface. The design can include additional internal reflections to increase interaction with the side pump. Waste heat may be removed by mounting the crystal to a heatsink.

  16. Semiconductor saturable absorber mirror passively Q-switched 2.97 μm fluoride fiber laser

    NASA Astrophysics Data System (ADS)

    Li, J. F.; Luo, H. Y.; He, Y. L.; Liu, Y.; Zhang, L.; Zhou, K. M.; Rozhin, A. G.; Turistyn, S. K.

    2014-06-01

    A diode-cladding-pumped mid-infrared passively Q-switched Ho3+-doped fluoride fiber laser using a reverse designed broad band semiconductor saturable mirror (SESAM) was demonstrated. Nonlinear reflectivity of the SESAM was measured using an in-house Yb3+-doped mode-locked fiber laser at 1062 nm. Stable pulse train was produced at a slope efficient of 12.1% with respect to the launched pump power. Maximum pulse energy of 6.65 µJ with a pulse width of 1.68 µs and signal-to-noise ratio (SNR) of ~50 dB was achieved at a repetition rate of 47.6 kHz and center wavelength of 2.971 µm. To the best of our knowledge, this is the first 3 µm region SESAM-based Q-switched fiber laser with the highest average power and pulse energy, as well as the longest wavelength from mid-infrared passively Q-switched fluoride fiber lasers.

  17. Semiconductor saturable absorber mirror passively Q-switched 2.97 μm fluoride fiber laser

    NASA Astrophysics Data System (ADS)

    Li, Jianfeng; Luo, Hongyu; He, Yulian; Liu, Yong; Luo, Binbin; Sun, Zhongyuan; Zhang, Lin; Turitsyn, Sergei K.

    2014-05-01

    A diode-cladding-pumped mid-infrared passively Q-switched Ho3+-doped fluoride fiber laser using a reverse designed broad band semiconductor saturable mirror (SESAM) was demonstrated. Nonlinear reflectivity of the SESAM was measured using an in-house Yb3+-doped mode-locked fiber laser at 1062 nm. Stable pulse train was produced at a slope efficient of 12.1% with respect to the launched pump power. Maximum pulse energy of 6.65 μJ with a pulse width of 1.68 μs and signal to noise ratio (SNR) of ~50 dB was achieved at a repetition rate of 47.6 kHz and center wavelength of 2.971 μm. To the best of our knowledge, this is the first 3 μm region SESAM based Q-switched fiber laser with the highest average power and pulse energy, as well as the longest wavelength from mid-infrared passively Q-switched fluoride fiber lasers.

  18. Passively Q-switched high-energy all-solid-state holographic Nd:YAG laser with a multiloop cavity

    NASA Astrophysics Data System (ADS)

    Lebedev, V. F.; Pogoda, A. P.; Boreysho, A. S.; Smetanin, S. N.; Fedin, A. V.

    2015-02-01

    A high-energy, high-beam-quality laser based on a single Nd:YAG rod with laser diode side-pumping and multiloop self-adaptive reciprocal cavity is presented. The optimized laser cavity geometry allowed to change the laser oscillation from single 200-ns self-Q-switched pulse followed by low-intensity free-running lasing to repetitive high-intensive pulses by periodically writing and erasing holographic gain gratings in the active Nd:YAG medium. The intensified self-Q-switching pulse train oscillation was realized by the interaction with a diffusely reflecting target placed in the focal plane of a lens at the laser output. Effects of shortening of the repetitive laser pulses down to 70-ns duration, stabilization of the pulse repetition period (~ 5 μs), and mode-locking temporal modulation of the pulses were observed. The use of a passive F2-:LiF Q-switch resulted in stable giant pulse train oscillation with total output energy of up to 0.43 J, individual pulse energy of 50 mJ, and its peak power of 4 MW at the individual pulse duration of 12 ns.

  19. Regimes of operation states in passively mode-locked fiber soliton ring laser

    NASA Astrophysics Data System (ADS)

    Gong, Y. D.; Shum, P.; Tang, D. Y.; Lu, C.; Guo, X.; Paulose, V.; Man, W. S.; Tam, H. Y.

    2004-06-01

    The principal of passively mode-locked fiber soliton ring lasers is summarized, including its three output operation states: normal soliton, bound-solitons and noise-like pulse. The experimental results of the passively mode-locked fiber soliton ring lasers developed by us are given. Bound-solitons with different discrete separations and three-bound-solitons state have been observed in our fiber laser for the first time. The relationship among three operation states in fiber soliton laser is analyzed.

  20. Numerical simulation of passively mode-locked fiber laser based on semiconductor optical amplifier

    NASA Astrophysics Data System (ADS)

    Yang, Jingwen; Jia, Dongfang; Zhang, Zhongyuan; Chen, Jiong; Liu, Tonghui; Wang, Zhaoying; Yang, Tianxin

    2013-03-01

    Passively mode-locked fiber laser (MLFL) has been widely used in many applications, such as optical communication system, industrial production, information processing, laser weapons and medical equipment. And many efforts have been done for obtaining lasers with small size, simple structure and shorter pulses. In recent years, nonlinear polarization rotation (NPR) in semiconductor optical amplifier (SOA) has been studied and applied as a mode-locking mechanism. This kind of passively MLFL has faster operating speed and makes it easier to realize all-optical integration. In this paper, we had a thorough analysis of NPR effect in SOA. And we explained the principle of mode-locking by SOA and set up a numerical model for this mode-locking process. Besides we conducted a Matlab simulation of the mode-locking mechanism. We also analyzed results under different working conditions and several features of this mode-locking process are presented. Our simulation shows that: Firstly, initial pulse with the peak power exceeding certain threshold may be amplified and compressed, and stable mode-locking may be established. After about 25 round-trips, stable mode-locked pulse can be obtained which has peak power of 850mW and pulse-width of 780fs.Secondly, when the initial pulse-width is greater, narrowing process of pulse is sharper and it needs more round-trips to be stable. Lastly, the bias currents of SOA affect obviously the shape of mode-locked pulse and the mode-locked pulse with high peak power and narrow width can be obtained through adjusting reasonably the bias currents of SOA.

  1. A passively mode locked thulium doped fiber laser using bismuth telluride deposited multimode interference

    NASA Astrophysics Data System (ADS)

    Jung, M.; Lee, J.; Song, W.; Lee, J. H.; Shin, W.

    2016-03-01

    We experimentally demonstrate a passively mode-locked thulium doped fiber laser using a bismuth telluride deposited multimode interference (MMI) fiber at a wavelength of 1958 nm. Our MMI based saturable absorber was fabricated by fusion splicing with single mode fiber and null core fiber. The center wavelength and insertion loss of MMI fiber were measured to be ~ 1958 nm and 3.4 dB. We observed a passively mode locked thulium doped fiber laser operating at a wavelength of 1958 nm. The temporal pulse width of output pulses is 4.2 ps with repetition rate of 22.7 MHz.

  2. 1357 nm passively Q-switched crystalline ceramic laser based on multilayer graphene

    NASA Astrophysics Data System (ADS)

    Feng, Chao; Zhang, Huanian; Wang, Qingpu; Xu, Shicai; Fang, Jiaxiong

    2016-05-01

    1357 nm single wavelength passively Q-switched Nd:YAG ceramic lasers are demonstrated with a multilayer graphene sheets saturable absorber (SA). During an increase in the incident pump power, the laser exhibited stable Q-switched oscillation, which showed that our graphene SA provided Q-switched modulation successfully. The maximum average output power was 340 mW, and the corresponding pulse width, pulse repetition rate, single pulse energy and peak power were 380 ns, 209 kHz, 53 μJ and 139 W, respectively. Our results illustrate that graphene can be used as an SA for 1357 nm passively Q-switched Nd:YAG ceramic lasers.

  3. Adjustable high-repetition-rate pulse trains in a passively-mode-locked fiber laser

    NASA Astrophysics Data System (ADS)

    Si Fodil, Rachid; Amrani, Foued; Yang, Changxi; Kellou, Abdelhamid; Grelu, Ph.

    2016-07-01

    We experimentally investigate multipulse regimes obtained within a passively-mode-locked fiber laser that includes a Mach-Zehnder (MZ) interferometer. By adjusting the time delay imbalance of the MZ, ultrashort pulse trains at multi-GHz repetition rates are generated. We compare the observed dynamics with high-harmonic mode locking, and show that the multi-GHz pulse trains display an inherent instability, which has been overlooked. By using a recirculation loop containing the MZ, we demonstrate a significant improvement of the pulse train stability.

  4. A diode pumped passively mode-locked Nd:CaGdAlO4 laser

    NASA Astrophysics Data System (ADS)

    Rao, H.; Cong, Z. H.; Qin, Z. G.; Feng, C.; Wang, Q. P.; Liu, Z. J.; Zhang, X. Y.; Zhang, S. S.; Liu, Y.; Men, S. J.; Xia, J. B.; Di, J. Q.; Xu, X. D.; Xu, J.

    2016-04-01

    A diode pumped passively mode-locked Nd:CaGdAlO4 (Nd:CGA) laser was demonstrated. By using a semiconductor saturable-absorber mirror (SESAM) as the modulator, stable mode-locked pulses with a duration of 6.0 ps and a repetition rate of 88.3 MHz have been achieved at a central wavelength of 1078.6 nm. The maximum output power of 452 mW was obtained under a pump power of 10 W.

  5. Passive mode locking of thin-disk lasers: effects of spatial hole burning

    NASA Astrophysics Data System (ADS)

    Paschotta, R.; Aus der Au, J.; Spühler, G. J.; Erhard, S.; Giesen, A.; Keller, U.

    We recently demonstrated that passive mode locking of a thin-disk Yb:YAG laser is possible and that this concept leads to sources of femtosecond pulses with very high average power. Here we discuss in detail the effect of spatial hole burning on the mode-locking behavior of such lasers. We have developed an efficient numerical model and arrive at quantitative stability criteria which agree well with experimental data. The main result is that stable soliton mode locking can in general be obtained only in a certain range of pulse durations. We use our model to investigate the influence of various cavity parameters and the situation for different gain media. We also consider several methods to reduce the effect of spatial hole burning in order to expand the range of possible pulse durations.

  6. Passively mode-locked Yb3+:Sc2SiO5 thin-disk laser.

    PubMed

    Wentsch, Katrin Sarah; Zheng, Lihe; Xu, Jun; Ahmed, Marwan Abdou; Graf, Thomas

    2012-11-15

    Experimental investigations on a passively mode-locked Yb(3+):Sc(2)SiO(5) (Yb:SSO) thin-disk laser are presented. The mode-locking was performed with a commercially available semiconductor saturable absorber mirror. The laser was operated at a repetition rate of 27 MHz and generated a maximum average output power of 27.8 W with a pulse duration of 298 fs. The spectrum was centered at 1036 nm. The beam was measured to be close to diffraction limited (M(2)<1.1). The promising results confirm the suitability of Yb:SSO for mode-locked thin-disk laser oscillators and indicate that this comparably new material deserves further attention by optimizing the crystal quality (growth and polishing) and doping levels for further power scaling. PMID:23164901

  7. Passively mode-locked picosecond erbium-doped fiber lasers using multiple quantum well saturable absorbers

    NASA Astrophysics Data System (ADS)

    Hayduk, Michael J.; Krol, Mark F.; Pollock, Clifford R.; Teegarden, Kenneth J.; Wicks, Gary W.; Kaechele, Walter

    1998-07-01

    An experimental study of the mode-locking process in erbium- doped fiber lasers (EDFLs) operating at 1.55 micrometer using multiple quantum well saturable absorbers is described. The self-starting passively mode-locked laser was constructed in a Fabry-Perot configuration using the saturable absorber as the back reflector of the cavity. Picosecond pulses that ranged from 3.1 to 38.8 ps were generated using a series of saturable absorbers. The pulse widths were dependent upon the optical properties of the saturable absorber used as the mode- locking element as well as the dispersive elements contained within the cavity. The output power of the EDFL varied from 0.2 to 6.7 mW and was also dependent upon the saturable absorber used in the cavity.

  8. Environmentally stable, simple passively mode-locked fiber ring laser using a four-port circulator.

    PubMed

    Masuda, Shin; Niki, Shoji; Nakazawa, Masataka

    2009-04-13

    We present here a self-starting passively mode-locked fiber ring laser with a novel cavity configuration using a four-port optical circulator. Our special ring cavity design enables highly stable mode-locked operation between 25 and 60 degrees C to be maintained without the need for any polarization-adjusting devices. The pulse width and the integrated timing jitter from 10 Hz to 10 MHz of our fiber ring laser were measured to be 120 fs and 39.1 fs, respectively. As a result, a robust and environmentally stable all-fiber mode-locked fiber ring laser with a simple ring cavity configuration in a small package has been achieved. PMID:19365487

  9. Bidirectional passively mode-locked soliton fiber laser with a four-port circulator.

    PubMed

    Ouyang, Chunmei; Shum, Ping; Wu, Kan; Wong, Jia Haur; Lam, Huy Quoc; Aditya, Sheel

    2011-06-01

    We present an all-fiber bidirectional passively mode-locked soliton laser with what we believe is a novel cavity configuration. Using a four-port circulator, we incorporate two different semiconductor saturable absorber mirrors (SESAMs) into the laser cavity, which enables bidirectional mode locking. The laser allows the generation of two independent countercirculating mode-locked pulse trains, each with an individual fundamental repetition rate that can be adjusted by varying the SESAM pigtail length. Two countercirculating pulse trains with repetition rates of 21.3 and 15.2 MHz are obtained simultaneously. By controlling the intracavity loss imposed on these two pulse trains, either one of the two pulse trains can be switched on or off. The bidirectional operation with other repetition rates is also demonstrated. PMID:21633458

  10. Repetition rate switching in a passively mode-locked fibre laser

    NASA Astrophysics Data System (ADS)

    Tian, X. L.; Tang, M.; Gong, Y. D.; Shum, P.

    2006-09-01

    Here we demonstrated a dispersion stretched passively mode-locked fiber laser. The laser was mode-locked by nonlinear polarization rotation (NPR) technical. Both dispersion managed soliton and noise-like pulses were observed in the experiment. Harmonic mode-locked noise-like pulses were observed. By changing the pump power or rotating the waveplates, noise-like pulse could split and always form equally spaced pulse train, thus the repetition rate of the output pulse could be switched among different orders of harmonic frequency. The experiment results were analyzed. We found that peak power clamping caused by NPR module led to pulse splitting, the pulse interaction through the Raman light drives the pulse to space equally.

  11. Three-dimensional graphene based passively mode-locked fiber laser.

    PubMed

    Yang, Y; Loeblein, M; Tsang, S H; Chow, K K; Teo, E H T

    2014-12-15

    We present an all-fiber passively mode-locked fiber laser incorporating three-dimensional (3D) graphene as a saturable absorber (SA) for the first time to the best of our knowledge. The 3D graphene is synthesized by template-directed chemical vapor deposition (CVD). The SA is then simply formed by sandwiching the freestanding 3D graphene between two conventional fiber connectors without any deposition process. It is demonstrated that such 3D graphene based SA is capable to produce high quality mode-locked pulses. A passively mode-locked fiber laser is constructed and stable output pulses with a fundamental repetition rate of ~9.9 MHz and a pulse width of ~1 ps are generated from the fiber laser. The average output power of the laser is ~10.5 mW while the output pulse is operating at single pulse region. The results imply that the freestanding 3D graphene can be applied as an effective saturable absorption material for passively mode-locked lasers. PMID:25607096

  12. Passive Q-Switching Laser Performance of Yb:YVO4 Crystal

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Hong; Chen, Xiao-Wen; Han, Wen-Juan; Kong, Wei-Jin; Liu, Jun-Hai

    2014-12-01

    We report on the passive Q-switching laser performance of Yb:YVO4 crystal. Utilizing a Cr4+:YAG crystal plate as the saturable absorber, which is of an initial transmission as high as 99.3%, we demonstrate a stable passively Q-switched laser operation at 1017.2 nm, producing an average output power of 0.87 W at a pulse repetition rate of 71.4 kHz, with a slope efficiency of 30%. The resulting pulse energy, duration, and peak power are 12.2 μJ, 87 ns, and 0.14 kW, respectively.

  13. Diode pumped CW and passively Q-switched Nd:LGGG laser at 1062 nm

    NASA Astrophysics Data System (ADS)

    Yang, H.; Jia, Z. T.; Zhang, B. T.; He, J. L.; Liu, S. D.; Yang, Y.; Tao, X. T.

    2012-05-01

    We report a Nd:LGGG laser at 1062 nm in the operations of the continuous-wave (CW) and passively Q-switching. The maximum CW output power of 5.62 W was obtained, corresponding to an optical-to-optical conversion efficiency of 49.0% and slope efficiency of 55.9%. By using Cr4+:YAG with initial transmission of 94% as the saturable absorber, for the first time, we got the maximum passively Q-switched output power of 1.21 W, accompanied with a highest pulse repetition rate of 27.1 kHz and a shortest pulse width of 9.1 ns.

  14. Passive Q-switching of Yb bulk lasers by a graphene saturable absorber

    NASA Astrophysics Data System (ADS)

    Loiko, P. A.; Serres, J. M.; Mateos, X.; Liu, J.; Zhang, H.; Yasukevich, A. S.; Yumashev, K. V.; Petrov, V.; Griebner, U.; Aguiló, M.; Díaz, F.

    2016-04-01

    Compact Yb:KLu(WO4)2 and Yb:LuVO4 lasers diode-pumped at 978 nm are passively Q-switched by a single-layer graphene saturable absorber. The Yb:KLu(WO4)2 laser generated 165 ns/0.49 μJ pulses at 1030 nm with 170 mW average output power and 12 % slope efficiency. With the Yb:LuVO4 laser, 152 ns/0.83 μJ pulses were achieved. The output power reached 300 mW at 1024 nm, and the slope efficiency was 10 %. Laser operation in a plano-plano cavity is achieved with both crystals with thermal lensing playing a key role in their performance. A model describing graphene Q-switched Yb lasers is developed. Our results indicate the potential of graphene for passive Q-switching of ~1 μm bulk lasers.

  15. Can silicon carbide serve as a saturable absorber for passive mode-locked fiber lasers?

    PubMed

    Cheng, Chih-Hsien; Lin, Yung-Hsiang; Chen, Ting-Hui; Chen, Hsiang-Yu; Chi, Yu-Chieh; Leeb, Chao-Kuei; Wua, Chih-I; Lin, Gong-Ru

    2015-01-01

    The study presents a novel demonstration of a passively mode-locked erbium-doped fiber laser (EDFL) that is based on a silicon carbide (SixC1-x) saturable absorber. When the C/Si composition ratio is increased to 1.83, the SixC1-x film transforms from two-photon absorption to nonlinear saturable absorption, and the corresponding value reaches -3.9 × 10(-6) cm/W. The Si-rich SixC1-x film cannot mode lock the EDFL because it induced high intracavity loss through two-photon absorption. Even when a stoichiometric SiC is used, the EDFL is mode locked, similar to an EDFL operating under weak nonlinear-polarization-rotation condition. A C-rich SixC1-x film containing sp(2)-orbital C-C bonds with a linear absorbance of 0.172 and nonlinear absorbance of 0.04 at a 181 MW/cm(2) saturation intensity demonstrates nonlinear transmittance. The C-rich SixC1-x saturable absorber successfully generates a short mode-locked EDFL pulse of 470 fs. The fluctuation of the pulse-train envelope dropps considerably from 11.6% to 0.8% when a strong saturable-absorption-induced self-amplitude modulation process occurs in the C-rich SixC1-x film. PMID:26558531

  16. Tunable passively harmonic mode-locked Yb-doped fiber laser with Lyot-Sagnac filter.

    PubMed

    Li, Ming; Zou, Xin; Wu, Jian; Shi, Jindan; Qiu, Jifang; Hong, Xiaobin

    2015-10-10

    A novel passively harmonic mode-locked dissipative soliton Yb-doped fiber laser with all normal dispersion is proposed and experimentally demonstrated based on a semiconductor saturable absorption mirror and tunable Lyot-Sagnac filter. By only tuning the bandwidth of the filter at fixed pump power, the repetition rate of 9.87 to 167.8 MHz (corresponding to 17th-order harmonic) is obtained. This is the highest repetition rate and harmonic order for a passively harmonic mode-locked dissipative soliton Yb-doped fiber laser with all-normal dispersion to the best of our knowledge. The signal-to-noise ratio and super-mode suppression ratio for all harmonic orders are higher than 65 and 35 dB, respectively, which shows the high stability of the fiber laser. PMID:26479821

  17. Passively mode-locked 1 GHz MOPA system generating sub-500-fs pulses after external compression

    NASA Astrophysics Data System (ADS)

    Ulm, Thorsten; Harth, Florian; Klehr, Andreas; Erbert, Götz; L'huillier, Johannes

    2012-06-01

    We compared the performance of DQW and TQW edge-emitters in a passively mode-locked 1GHz MOPA system at 1075 nm wavelength. Passive mode-locking is induced by applying a reverse DC voltage to the absorber section. The average power is increased up to 0.9Wby a single-stripe pre-amplifier and a tapered amplifier. After compensation of the quadratic chirp in a grating compressor we achieved a pulse duration of 342 fs. We found that the oscillator gain current and the absorber bias voltage have significant impact on the pulse duration. Both parameters were used to optimize the MOPA system with respect to the shortest pulse length after compression.

  18. Numerical simulation and optimization of passively q-switched erbium microchip lasers

    NASA Astrophysics Data System (ADS)

    Belghachem, Nabil; Mlynczak, Jarslow

    2015-08-01

    In this article we present a procedure of optimization of passively q-switched erbium microchip lasers. The procedure is based on the rate equation model, validated by comparing the numerical results to the experimental results of pulse generation in different types of erbium/ytterbium glass microchips q-switched by Co2+ : MgAl2O4 saturable absorber. Some Degnan’s optimization limitations in case of microchip lasers were also shown and the reabsorbtion cross section of erbium glass was also estimated.

  19. High brightness photonic band crystal semiconductor lasers in the passive mode locking regime

    SciTech Connect

    Rosales, R.; Kalosha, V. P.; Miah, M. J.; Bimberg, D.; Posilović, K.; Pohl, J.; Weyers, M.

    2014-10-20

    High brightness photonic band crystal lasers in the passive mode locking regime are presented. Optical pulses with peak power of 3 W and peak brightness of about 180 MW cm{sup −2} sr{sup −1} are obtained on a 5 GHz device exhibiting 15 ps pulses and a very low beam divergence in both the vertical and horizontal directions.

  20. Performance of passive Q-switched solar-pumped high-power Nd:YAG lasers

    NASA Astrophysics Data System (ADS)

    Noter, Yoram; Naftali, Nir; Pe'er, Idit L.; Yogev, Amnon; Lando, Mordechai; Shimony, Yehoshua

    1997-09-01

    Q-switched, solar-pumped, high power Nd:YAG lasers are attractive for a variety of applications requiring high instantaneous peak power density. The Q-switching can be obtained by an acousto-optic, electro-optic or passive device. Passive Q-switching seems an excellent choice for space as well as for other applications since it neither requires an external driver nor an electrical power supply. In recent years Cr+4:YAG single crystals were extensively used as passive Q-switches for flashlamp-pumped high power Nd:YAG lasers, demonstrating their superior thermal superior thermal characteristics and durability. In this work we report the first operation of passive Q- switched, solar-pumped, high power Nd:YAG lasers. The concentrated solar energy for he optical pumping of the laser was obtained by a 3-stage combination of imaging and non-imaging optics. It included: i) Weizmann Institute solar tower heliostats, ii) 3D compound parabolic concentrator, and iii) 2D compound parabolic concentrator in which the laser rod was placed. 72 mm long laser rods with either 3 mm or 4 mm diameter were used. The passive Q-switch was made from a Cr$=+4):YAG single crystal having a low- intensity transmission of 72 percent at 1.06 (mu) . Its rear surface was coated by a high reflectivity coating, serving as the rear mirror of the cavity. Output coupling mirrors with various reflectivities were used. The passive Q-switch demonstrated excellent durability and reliability during all the experiments. Repetition rates of 6-39 kHz were measured, showing higher repetition rates at higher laser power levels. The pulses demonstrated shorter full width at half maximum (FWHM) time for higher laser power elves, and the FWHM time range was 190-310 nsec. The maximal measured average power was 14 W. Thermal lensing was measured as a function of the absorbed solar power in the laser rod. It is estimated that laser peak power densities of approximately 100 kW/cm2 were achieved in the experiments. It is

  1. Passively mode-locked erbium-doped fiber lasers using multiple quantum well saturable absorbers

    NASA Astrophysics Data System (ADS)

    Hayduk, Michael Joseph

    1997-09-01

    An experimental study of the mode-locking process in erbium-doped fiber lasers (EDFL's) operating at 1.55 μm using multiple quantum well saturable absorbers is presented. The self-starting passively mode-locked laser was constructed in a Fabry-Perot configuration using the saturable absorber as the back reflector of the cavity. Picosecond pulses that ranged from 14.2 to 38.8 ps were generated using a series of saturable absorbers. The pulse widths were dependent upon the optical properties of the saturable absorber used as the mode-locking element. The output power of the EDFL varied from 0.2 to 6.7 mW and was also dependent upon the saturable absorber used in the cavity. Soliton mode-locking using saturable absorbers was the mechanism responsible for the generation of the picosecond pulses by the EDFL. The long-lived carrier lifetime in the quantum wells was the primary optical property of the saturable absorber that determined the final pulse width. The carrier lifetimes of the eight individual saturable absorbers were investigated using time-resolved pump/probe experimental techniques. The lifetimes ranged from 40 to 1757 ps. The soliton mode- locking process allowed pulse widths of up to 45 times shorter than these carrier lifetimes to be produced. A self-starting passively mode-locked solid-state Cr4+:YAG laser was also developed using a novel saturable absorber mirror structure. The laser produced femtosecond pulses that were tunable from 1.488 to 1.535 μm. The average output power of the laser ranged from 40 to 80 mW at a repetition rate of 95 MHz. A minimum pulse width of 120 fs was generated at 1.488 μm. The high peak power of these pulses combined with its tunability in the 1.5 μm region made this laser an ideal spectroscopic source for use in the time-resolved pump/probe experiments.

  2. Timing characterization of 100 GHz passively mode-locked discrete mode laser diodes.

    PubMed

    Bitauld, David; Osborne, Simon; O'Brien, Stephen

    2011-07-18

    We report on the characterization of the timing stability of passively mode-locked discrete mode diode laser sources. These are edge-emitting devices with a spatially varying refractive index profile for spectral filtering. Two devices with a mode-locking frequency of 100 GHz are characterized. The first device is designed to support a comb of six modes and generates near Fourier limited 1.9 ps pulses. The second supports four primary modes resulting in a sinusoidal modulation of the optical intensity. Using a cross-correlation technique, we measured a 20 fs pulse to pulse timing jitter for the first device, while, for the second device, a mode-beating (RF) linewidth of 1 MHz was measured using heterodyne mixing in a semiconductor optical amplifier. Comparison of these results with those obtained for an equivalent Fabry-Perot laser indicates that the spectral filtering mechanism employed does not adversely affect the timing properties of these passively mode-locked devices. PMID:21934760

  3. High-power diode-pumped passively mode-locked Yb:YAG lasers.

    PubMed

    Aus der Au, J; Schaer, S F; Paschotta, R; Hönninger, C; Keller, U; Moser, M

    1999-09-15

    We obtained 74-kW peak power and 3.5-W average output power in 1-ps pulses from a diode-pumped Yb:YAG laser at 1030 nm that was passively mode locked with a semiconductor saturable-absorber mirror. Another laser produced 57-kW peak power and as much as 8.1-W average output power in 2.2-ps pulses, split into two nearly diffraction-limited beams (M(2)<1.2) . To our knowledge, these are by far the highest reported peak and average output powers from a diode-pumped mode-locked laser in this pulse-duration regime. PMID:18079780

  4. Frequency doubling of a passively mode-locked monolithic distributed Bragg reflector diode laser.

    PubMed

    Jedrzejczyk, D; Prziwarka, T; Klehr, A; Brox, O; Wenzel, H; Paschke, K; Erbert, G

    2014-05-20

    In this work, frequency doubling of a passively mode-locked 3.5 mm long monolithic distributed Bragg reflector diode laser is investigated experimentally. At 1064 nm, optical pulses with a duration of 12.4 ps are generated at a repetition rate of 13 GHz and a peak power of 825 mW, resulting in an average power of 133 mW. Second-harmonic generation is carried out in a periodically poled MgO-doped LiNbO₃ ridge waveguide at a normalized nonlinear conversion efficiency of 930%/W. A maximum average second-harmonic power of 40.9 mW, corresponding to a pulse energy of 3.15 pJ, is reached in the experiment at an opto-optical conversion efficiency of 30.8%. The normalized nonlinear conversion efficiency in mode-locked operation is more than 2 times larger compared to continuous-wave operation. PMID:24922212

  5. Gas laser mode-locking using an external acoustooptic modulator with a potential application to passive ring gyroscopes

    SciTech Connect

    Dunn, R.W.; Hendow, S.T.; Small, J.G.; Stijns, E.

    1982-11-15

    In this Letter, we show that the fundamental pulsation frequency of the mode-locked laser can be multiplied by an integer number by simply changing the length of a secondary cavity formed by the AOM and an external mirror. Furthermore, we show that a mode-locked laser may be used to enhance the SNR in passive ring gyroscopes by matching multiple modes of the laser to those of the passive cavity.

  6. Optimization of passively mode-locked quasi-continuously diode-pumped Nd:GdVO4 laser in bounce geometry

    NASA Astrophysics Data System (ADS)

    Frank, Milan; Jelínek, Michal; Kubeček, Václav

    2015-01-01

    In this paper the operation of pulsed diode-pumped Nd:GdVO4 laser oscillator in bounce geometry passively modelocked using semiconductor saturable absorber mirror (SAM), generating microjoule level picosecond pulses at wavelength of 1063 nm, is reported. Optimization of the output coupling for generation either Q-switched mode locked pulse trains or cavity dumped single pulses with maximum energy was performed, which resulted in extraction of single pulses as short as 10 ps and energy of 20 uJ. In comparison with the previous results obtained with this Nd:GdVO4 oscillator and saturable absorber in transmission mode, the achieved pulse duration is five times shorter. Using different absorbers and parameters of single pulse extraction enables generation of the pulses with duration up to 100 ps with the energy in the range from 10 to 20 μJ.

  7. Can silicon carbide serve as a saturable absorber for passive mode-locked fiber lasers?

    PubMed Central

    Cheng, Chih-Hsien; Lin, Yung-Hsiang; Chen, Ting-Hui; Chen, Hsiang-Yu; Chi, Yu-Chieh; Leeb, Chao-Kuei; Wua, Chih-I; Lin, Gong-Ru

    2015-01-01

    The study presents a novel demonstration of a passively mode-locked erbium-doped fiber laser (EDFL) that is based on a silicon carbide (SixC1−x) saturable absorber. When the C/Si composition ratio is increased to 1.83, the SixC1−x film transforms from two-photon absorption to nonlinear saturable absorption, and the corresponding value reaches −3.9 × 10−6 cm/W. The Si-rich SixC1−x film cannot mode lock the EDFL because it induced high intracavity loss through two-photon absorption. Even when a stoichiometric SiC is used, the EDFL is mode locked, similar to an EDFL operating under weak nonlinear-polarization-rotation condition. A C-rich SixC1−x film containing sp2-orbital C–C bonds with a linear absorbance of 0.172 and nonlinear absorbance of 0.04 at a 181 MW/cm2 saturation intensity demonstrates nonlinear transmittance. The C-rich SixC1−x saturable absorber successfully generates a short mode-locked EDFL pulse of 470 fs. The fluctuation of the pulse-train envelope dropps considerably from 11.6% to 0.8% when a strong saturable-absorption-induced self-amplitude modulation process occurs in the C-rich SixC1−x film. PMID:26558531

  8. Passively Q-switching induced by the smallest single-walled carbon nanotubes

    SciTech Connect

    Xu, X. T.; Zhai, J. P.; Wang, J. S.; Chen, Y. P.; Yu, Y. Q.; Zhang, M.; Li, I. L.; Ruan, S. C.; Tang, Z. K.

    2014-04-28

    We report a passively Q-switched erbium-doped fiber laser (EDFL) by using the smallest single-walled carbon nanotubes (SWNTs) with a diameter of 0.3 nm as the saturable absorber. These small SWNTs are fabricated in the nanochannels of a ZnAPO-11 (AEL) single crystal. By inserting one of the AEL crystal into an EDFL cavity pumped by a 980 nm laser diode, stable passive Q-switching is achieved for a threshold pump power of 206.2 mW, and 4.73 μs pulses with a repetition rate of 41.78 kHz and an average output power of 3.75 mW are obtained for a pump power of 406 mW.

  9. Passively Q-switched microchip lasers based on Yb:YAG/Cr4+:YAG composite crystal

    NASA Astrophysics Data System (ADS)

    Ren, Yingying; Dong, Jun

    2014-02-01

    Efficient passively Q-switched microchip laser based on Yb:YAG/Cr4+:YAG composite crystal has been demonstrated under high brightness single-emitter laser-diode pumping. Maximum average output power of 1.5 W was obtained when the absorbed pump power was 3.65 W, the corresponding optical-to-optical efficiency was over 41%. The slope efficiency was 52.3%. The effect of the cavity length on the performance of Yb:YAG/Cr4+:YAG composite crystal passively Q-switched microchip lasers was investigated. Laser pulses at 1030 nm with pulse width of 466 ps and peak power of 91 kW were achieved with cavity length of 1.7 mm, while laser pulses with pulse width of 665 ps and peak power of 79 kW were obtained with cavity length of 3.7 mm.

  10. Reciprocal passive mode locking of a rhodamine 6G dye laser and the Ar+ pump laser

    SciTech Connect

    Yasa, Zafer A.; Amer, Nabil M.

    1981-02-01

    We report that a rhodamine 6G dye laser, internally pumped within the extended cavity of an Ar+-ion laser, is mode locked when its cavity length is matched to half that of the pump laser: the 5145-Å argon laser line is passively mode locked by the combination of the saturable absorption and the lasing action of the dye, which is in turn synchronously pumped and mode locked. Tunable (5650–5950-Å) ~10 psec pulses are generated, and the average output power is ~80 mW.

  11. Reciprocal passive mode locking of a rhodamine 6G dye laser and the Ar/sup +/ pump laser

    SciTech Connect

    Yasa, Z.A.; Amer, N.M.

    1981-02-01

    A rhodamine 6G dye laser, internally pumped within the extended cavity of an Ar/sup +/-ion laser, is mode locked when its cavity length is matched to half that of the pump laser: the 5145-A argon laser line is passively mode locked by the combination of the saturable absorption and the lasing action of the dye, which is in turn synchronously pumped and mode locked. Tunable (5650-5950-A)approx.10 psec pulses are generated, and the average output power is approx.80 mW.

  12. Self-stabilized and dispersion-compensated passively mode-locked Yb:Yttrium aluminum garnet laser

    NASA Astrophysics Data System (ADS)

    Agnesi, A.; Guandalini, A.; Reali, G.

    2005-04-01

    Self-stabilized passive mode-locking of a diode-pumped Yb:yttrium aluminum garnet laser with a semiconductor saturable absorber was achieved using an off-phase-matching second-harmonic crystal. According to the numerical model, such a condition is accomplished by self-defocusing in the nonlinear crystal in the presence of positive intracavity dispersion. Robust mode locking with Fourier-limited 1.0-ps pulses was obtained, whereas mode locking, unassisted by the nonlinear crystal, yielded 2.2-ps pulses, with the laser operating near the edge of the stability region in order to minimize the saturation energy of the semiconductor device.

  13. Pulse synchronisation in passively Q-switched lasers emitting at 1.053 and 1.064 {mu}m

    SciTech Connect

    Bagdasarov, V Kh; Denisov, N N; Malyutin, A A; Chigaev, I A

    2009-10-31

    Pulse synchronisation with an accuracy of no worse than {+-}5 ns is demonstrated in passively Q-switched neodymium phosphate glass and Nd:YAG lasers. Two operating regimes are realised: the 'sub-threshold' regime (when the slave Nd:YAG laser does not generate a giant pulse if its passive Q switch is not irradiated by the master Nd:glass laser) and the 'above-threshold' regime (when the pulse irradiating the passive Q switch of the slave laser advances its generation). (control of laser radiation parameters)

  14. Generation of single longitudinal mode in a pulsed passively Q -switched Nd:YAG laser

    SciTech Connect

    Hariri, A.; Soltanmoradi, F.; Nayeri, M. )

    1990-08-01

    It is shown that a single longitudinal mode in a passively {ital Q}-switch Nd:YAG laser can be obtained by adjusting an intracavity saturable absorber gelatin film (BDN) to work as a mirror in a three-mirror Fabry--Perot resonator. With a 0.13-mm-thick gelatin film of 40% unsaturated transmission, a temporally smooth single-laser pulse of {similar to}10 ns duration has been obtained.

  15. Theory of stationary ultarshort pulses in solid-state laserswith passive mode locking

    SciTech Connect

    Komarov, K.P.

    1986-02-01

    The formation of steady-state pulses in solid-state lasers with passive mode locking is investigated under conditions when the refractive index is frequency dispersive and nonlinear. The case of a noninertial absorber is considered as well as that of an inertial one. It is shown that when the nonlinearity of the refractive index exceeds a certain critical level phase modulation of the pulse leads to instability of the steady-state regime. The possibility is discussed of forming extremely short pulses in wide-band amplifying media such as alexandrite.

  16. 1.21 W passively mode-locked Tm:LuAG laser.

    PubMed

    Feng, T; Yang, K; Zhao, J; Zhao, S; Qiao, W; Li, T; Dekorsy, T; He, J; Zheng, L; Wang, Q; Xu, X; Su, L; Xu, J

    2015-05-01

    A watt-level output passively mode-locked Tm:LuAG bulk laser with an InGaAs semiconductor saturable absorber mirror (SESAM) is demonstrated for the first time. A maximum average output power of 1.21 W at 2022.9 nm has been achieved with a pulse duration of 38 ps and a repetition rate of 129.2 MHz. The results indicate the potential of Tm:LuAG crystals as candidate for realizing high power ultrafast lasers at 2 μm. PMID:25969273

  17. Passive mode locking of an energy transfer continuous-wave dye laser

    SciTech Connect

    French, P.M.W.; Taylor, J.R.

    1986-08-01

    The first passive mode locking of a continuous-wave energy transfer dye laser is reported. Using an argon ion laser-pumped mixture of rhodamine 6G and sulphur rhodamine 101 as the active medium, pulses of less than 500 fs duration have been generated over the spectral range 652-694 nm using two different saturable absorbers in a simple linear cavity without dispersion optimization. Pulses as short as 120 fs have been measured using standard second-harmonic generation autocorrelation techniques.

  18. Picosecond pulse generation in a passively mode-locked Bi-doped fibre laser

    SciTech Connect

    Krylov, Aleksandr A; Kryukov, P G; Dianov, Evgenii M; Okhotnikov, Oleg G

    2009-10-31

    CW passive mode locking is achieved in a bismuth-doped fibre laser using a semiconductor saturable absorber mirror optimised for operation in the range 1100-1200 nm. The pump source is a cw ytterbium fibre laser (1075 nm, maximum output power of 2.7 W), and the pulse parameters can be tuned by varying the intracavity group velocity dispersion using a diffraction grating pair. Stable laser pulses are obtained with a duration down to {tau}{sub p} {approx} 1.1 ps. (control of laser radiation parameters)

  19. The design of passively Q-switched solid-state lasers

    NASA Astrophysics Data System (ADS)

    Xiao, Guohua

    The passively Q-switched laser has been of intense interest because it is generally simple, convenient, and requires a minimum of intracavity elements and no external high voltage or RF drivers. Z-scan technique was used to obtain more realistic values of the ground and excited state absorption cross sections of Cr:YAG, one of the most important solid state saturable absorbers. Other spectroscopic research revealed that Cr:YAG performs stably over the wide temperature range from -70 to +80°C. A generalized model of a passively Q-switched laser was developed. It enables performance optimization including general cases in which the saturable absorber exhibits both ground and excited state absorption at the laser wavelength. Based on the theory, we built and tested a Nd:glass laser passively Q-switched by a Cr4+:YAG crystal and found excellent agreement with our model. The model was then extended to the case where an optical parametric oscillator (OPO) is contained inside the passively Q-switched laser cavity. In such a laser there is no output at the fundamental or pump wavelength. When the OPO signal field begins to build up, it acts as a loss for the pump and cavity dumps the pump resonator. The extended model describes the complicated interactions between the fundamental laser gain medium, saturable absorber, fundamental laser cavity, and OPO cavity. The model developed enables one to select OPO parameters which optimize the system's performance. Application of the model to a very compact, lightweight, eye-safe laser range finder operating at 1.54 μm will also be presented. Many applications demand lasers to be operated over a wide temperature range (-55-75°C). Efforts were dedicated to obtaining information on the temperature dependence of the emission cross section of Nd,Cr:GSGG and the optical properties of certain laser resonator optics. The data serve as input parameters to the models to design passively Q-switched laser systems with predictable

  20. Passively Q-switched waveguide lasers based on two-dimensional transition metal diselenide.

    PubMed

    Cheng, Chen; Liu, Hongliang; Tan, Yang; Vázquez de Aldana, Javier R; Chen, Feng

    2016-05-16

    We reported on the passively Q-switched waveguide lasers based on few-layer transition metal diselenide, including molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2), as saturable absorbers. The MoSe2 and WSe2 membranes were covered on silica wafers by chemical vapor deposition (CVD). A low-loss depressed cladding waveguide was produced by femtosecond laser writing in a Nd:YAG crystal. Under optical pump at 808 nm, the passive Q-switching of the Nd:YAG waveguide lasing at 1064 nm was achieved, reaching maximum average output power of 115 mW (MoSe2) and 45 mW (WSe2), respectively, which are corresponding to single-pulse energy of 36 nJ and 19 nJ. The repetition rate of the Q-switched waveguide lasers was tunable from 0.995 to 3.334 MHz (MoSe2) and 0.781 to 2.938 MHz (WSe2), and the obtained minimum pulse duration was 80ns (MoSe2) and 52 ns (WSe2), respectively. PMID:27409862

  1. Passively Q-switched diode-pumped Yb:YAG laser using Cr 4+-doped garnets

    NASA Astrophysics Data System (ADS)

    Kalisky, Y.; Labbe, C.; Waichman, K.; Kravchik, L.; Rachum, U.; Deng, P.; Xu, J.; Dong, J.; Chen, W.

    2002-06-01

    We investigate the repetitive modulation in the kHz frequency domain of a passively Q-switched, diode-pumped Yb:YAG laser, by Cr 4+:YAG, Cr 4+:LuAG, and Cr 4+:GSGG saturable absorbers. The results presented here are focused towards the design of a passively Q-switched Yb:YAG microlaser. The free-running performance of both rod and a disk Yb:YAG is characterized and experimental parameters such as gain and loss are evaluated. These values, together with the value of the stimulated emission cross-section, e.g. σem=3.3×10 -20 cm 2 were found to fit between our experimental results and an existing numerical model which relates the experimental and physical parameters to the minimal threshold pumping power. Q-switched pulses with maximum peak power of ≈10.4 kW, with energy of ≈0.5 mJ/pulse, were extracted with 30% extraction efficiency.

  2. Passively Q-switched diode-pumped Yb:YAG laser using Cr4+-doped garnets

    NASA Astrophysics Data System (ADS)

    Kalisky, Yehoshua Y.; Labbe, Christophe; Waichman, Karol; Kravchik, Leonid; Rachum, U.; Deng, Peizhen; Xu, Jun; Dong, Jun; Chen, Wei

    2002-03-01

    We investigated the operation of a diode-pumped Yb:YAG laser passively Q-switched, by Cr4+:YAG, Cr4+:LuAG, and Cr4+:GSGG saturable absorbers. The results presented here are focused towards the design of a passively Q-switched Yb:YAG microlaser. The free-running performance of both rod and a disk Yb:YAG is characterized, and experimental parameters such as gain and loss are evaluated. These values, together with the value of the stimulated emission cross section, e.g. (sigma) emequals3.3x10-20 cm2 were found to fit between our experimental results and an existing numerical model which relates the experimental and physical parameters to the minimal threshold pumping power. Q-switched pulses with maximum peak power of approximately equals 10.4-kW, and energy of approximately equals 0.5 mJ/pulse were extracted with 30% extraction efficiency.

  3. Multi-Billion Shot, High-Fluence Exposure of Cr(4+): YAG Passive Q-Switch

    NASA Technical Reports Server (NTRS)

    Stephen, Mark A.; Dallas, Joseph L.; Afzal, Robert S.

    1997-01-01

    NASA's Goddard Space Flight Center is developing the Geoscience Laser Altimeter System (GLAS) employing a diode pumped, Q-Switched, ND:YAG laser operating at 40 Hz repetition rate. To meet the five-year mission lifetime goal, a single transmitter would accumulate over 6.3 billion shots. Cr(4+):YAG is a promising candidate material for passively Q-switching the laser. Historically, the performance of saturable absorbers has degraded over long-duration usage. To measure the multi-billion shot performance of Cr(4+):YAG, a passively Q-switched GLAS-like oscillator was tested at an accelerated repetition rate of 500 Hz. The intracavity fluence was calculated to be approximately 2.5 J/cm(exp 2). The laser was monitored autonomously for 165 days. There was no evidence of change in the material optical properties during the 7.2 billion shot test.. All observed changes in laser operation could be attributed to pump laser diode aging. This is the first demonstration of multi-billion shot exposure testing of Cr(4+):YAG in this pulse energy regime

  4. Continuous-wave and passively Q-switched cladding-pumped planar waveguide lasers.

    PubMed

    Beach, R J; Mitchell, S C; Meissner, H E; Meissner, O R; Krupke, W F; McMahon, J M; Bennett, W J; Shepherd, D P

    2001-06-15

    Greater than 12 W of average output power has been generated from a diode-pumped Yb:YAG cladding-pumped planar waveguide laser. The laser radiation developed is linearly polarized and diffraction limited in the guiding dimension. A slope efficiency of 0.5 W/W with a peak optical-optical conversion efficiency of 0.31 W/W is achieved. In a related structure, greater than 8 W of Q -switched average output power has been generated from a Nd:YAG cladding-pumped planar waveguide laser by incorporation of a Cr(4+): YAG passive Q switch monolithically into the waveguide structure. Pulse widths of 3 ns and pulse-repetition frequencies as high as 80 kHz have been demonstrated. A slope efficiency of 0.28 W/W with a peak optical-optical conversion efficiency of 0.21 W/W is achieved. PMID:18040479

  5. Dual-wavelength passively Q-switched Nd:GYSGG laser by tungsten disulfide saturable absorber.

    PubMed

    Gao, Y J; Zhang, B Y; Song, Q; Wang, G J; Wang, W J; Hong, M H; Dou, R Q; Sun, D L; Zhang, Q L

    2016-06-20

    A dual-wavelength passively Q-switched Nd:GYSGG laser using vacuum evaporating tungsten disulfide (WS2) as a saturable absorber was demonstrated for the first time to the best of our knowledge. The WS2 saturable absorber was prepared simply by evaporating nanometer WS2 powders onto a quartz substrate in a vacuum. By inserting the WS2 saturable absorber into the laser cavity, stable Q-switched laser operation was achieved with a maximum average output power of 367 mW, a pulse repetition rate of 70.7 kHz, the shortest pulse width of 591 ns, and pulse energy of about 1.05 μJ. By vacuum evaporation method, a high-quality WS2 saturable absorber can be produced, and it seems to be a suitable method for fabrication of 2D transition metal dichalcogenides. PMID:27409120

  6. Passively Q-switched nd:YAG laser via a WS2 saturable absorber

    NASA Astrophysics Data System (ADS)

    Wang, Xi; Wang, Yonggang; Duan, Lina; Li, Lu; Sun, Hang

    2016-05-01

    In this work, we report a passively Q-switched Nd:YAG laser at 1064 nm by using WS2 solution as the saturable absorber (SA). The WS2 solution with different concentrations (0.25, 0.5, and 1 mg/ml) were fabricated by the liquid-phase-exfoliated method and injected into quartz cells. Such liquid absorbers have the virtues of adjustable optical absorption, high heat dissipation and non-contact damage. By inserting those WS2 solutions in the laser cavity, stable Q-switched laser operations were obtained. The corresponding pulse duration as short as 922 ns was obtained. The result shows that the WS2 material can be act as absorber for solid-state lasers.

  7. LASERS: Small autonomous passively Q-switched Nd3+:YAG laser with a Cr4+:YAG Q switch emitting pulse trains

    NASA Astrophysics Data System (ADS)

    Buzinov, N. M.; Dmitriev, Valentin G.; Zabavin, V. N.; Kazakov, A. A.; Maslov, A. A.; Spitsyn, E. M.

    2007-04-01

    The energy and time characteristics of a passively Q-switched Nd3+:YAG laser with a Cr4+:YAG Q switch emitting pulse trains are studied and analysed theoretically. The description and technical parameters of a small autonomous laser with intracavity second-harmonic generation (ICSHG) in the pulse-train regime are presented. The laser provides a high total pulse-train energy for a relatively low peak power of a single pulse, stable operation in a wide temperature range, and has a small weight and size, which is convenient in operation. The enhanced reliability and stability of the laser operation are provided by its original technical design: the ICSHG scheme for type II phase matching without polarisers, the use of temperature-noncritical phase matching in KTP crystals, dust- and moisture-proof casing, and battery-operated pulsed power supply for the pump flashlamp.

  8. Efficient continuous wave and passively mode-locked Tm-doped crystalline silicate laser.

    PubMed

    Yang, K J; Bromberger, H; Heinecke, D; Kölbl, C; Schäfer, H; Dekorsy, T; Zhao, S Z; Zheng, L H; Xu, J; Zhao, G J

    2012-08-13

    An efficient continuous wave and passively mode-locked thulium-doped oxyorthosilicate Tm:LuYSiO5 laser is demonstrated. A maximum slope efficiency of 56.3% is obtained at 2057.4 nm in continuous wave operation regime. With an InGaAs quantum well SESAM, self-starting passively mode-locked Tm:LuYSiO5 laser is realized in the 1929 nm to 2065 nm spectral region. A maximum average output power of 130.2 mW with a pulse duration of 33.1 ps and a repetition rate of about 100 MHz is generated at 1984.1 nm. Pulses as short as 24.2 ps with an average output power of 100 mW are obtained with silicon prisms where used to manage the intracavity dispersion. The shortest pulse duration of about 19.6 ps is obtained with an average output power of 64.5 mW at 1944.3 nm. PMID:23038503

  9. Passive Q-switching of microchip lasers based on Ho:YAG ceramics.

    PubMed

    Lan, R; Loiko, P; Mateos, X; Wang, Y; Li, J; Pan, Y; Choi, S Y; Kim, M H; Rotermund, F; Yasukevich, A; Yumashev, K; Griebner, U; Petrov, V

    2016-06-20

    A Ho:YAG ceramic microchip laser pumped by a Tm fiber laser at 1910 nm is passively Q-switched by single- and multi-layer graphene, single-walled carbon nanotubes (SWCNTs), and Cr2+:ZnSe saturable absorbers (SAs). Employing SWCNTs, this laser generated an average power of 810 mW at 2090 nm with a slope efficiency of 68% and continuous wave to Q-switching conversion efficiency of 70%. The shortest pulse duration was 85 ns at a repetition rate of 165 kHz, and the pulse energy reached 4.9 μJ. The laser performance and pulse stability were superior compared to graphene SAs even for a different number of graphene layers (n=1 to 4). A model for the description of the Ho:YAG laser Q-switched by carbon nanostructures is presented. This modeling allowed us to estimate the saturation intensity for multi-layered graphene and SWCNT SAs to be 1.2±0.2 and 7±1  MW/cm2, respectively. When using Cr2+:ZnSe, the Ho:YAG microchip laser generated 11 ns/25 μJ pulses at a repetition rate of 14.8 kHz. PMID:27409113

  10. Reduced group delay dispersion in quantum dot passively mode-locked lasers operating at elevated temperature

    NASA Astrophysics Data System (ADS)

    Mee, J. K.; Raghunathan, R.; Murrell, D.; Braga, A.; Li, Y.; Lester, L. F.

    2014-09-01

    A detailed study of the pulse characteristics emitted from a monolithic Quantum Dot (QD) passively Mode-Locked Laser (MLL) has been performed using a state-of-the-art Frequency Resolved Optical Gating (FROG) pulse measurement system. While traditionally the time-domain pulse characteristics of semiconductor MLLs have been studied using digital sampling oscilloscope or intensity autocorrelation techniques, the FROG measurements allow for simultaneous characterization of time and frequency, which has been shown to be necessary and sufficient for true determination of mode-locked stability. In this paper, FROG pulse measurements are presented on a two-section QD MLL operating over wide temperature excursions. The FROG measurement allows for extraction of the temporal and spectral intensity and phase profiles from which the Group Delay Dispersion (GDD) can be determined. The magnitude of the GDD is found to decrease from 16.1 to 3.5 ps/nm when the temperature is increased from 20 to 50 oC, mirroring the trend of pulse width reduction at elevated temperature, which has been shown to correlate strongly with reduced unsaturated absorption. The possibility to further optimize pulse generation via intra-cavity dispersion compensation in a novel three-section MLL design is also examined, and shows strong potential toward providing valuable insight into the optimal cavity designs and operating parameters for QD MLLs.

  11. Influence of pumping schemes on the characteristics of self-similar pulses in a passively mode-locked fiber laser

    NASA Astrophysics Data System (ADS)

    Huo, Jiayu; Xu, Tiantian; Guo, Yubin; Wang, Ke; Gao, Bo

    2016-05-01

    Self-similar pulses are one of the domestic and international research hotspots in the field of nonlinear fiber optics because it can suppress optical wave breaking at high energies. The influence of pumping schemes on the characteristics of self-similar pulses in a passively mode-locked Yb-doped fiber laser is theoretically investigated. The temporal profile and optical spectrum of self-similar pulses in passively mode-locked fiber lasers of different pumping schemes are obtained in the simulation. This study focuses on analyzing the influence of gain bandwidth of gain fiber on the pulse duration, peak power, and single-pulse energy of self-similar pulses.

  12. Pulse and noise properties of a two section passively mode-locked quantum dot laser under long delay feedback

    NASA Astrophysics Data System (ADS)

    Simos, Christos; Simos, Hercules; Mesaritakis, Charis; Kapsalis, Alexandros; Syvridis, Dimitris

    2014-02-01

    We present a numerical analysis that focuses on the temporal pulse properties of a monolithic two-section passively mode locked quantum dot laser subject to optical feedback from a very long external cavity. Pulse duration, shape and intensity noise are studied for the first time to our knowledge versus feedback delay and strength for the case of a passively mode locked semiconductor laser. These temporal characteristics are correlated to the previously observed dependence of repetition rate and timing jitter on cavity parameters in order to highlight the dynamics and complete the corresponding theoretical explanations.

  13. Azimuthally polarized, passively Q-switched Yb-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Zou, Lin; Yao, Yao; Han, Xiahui; Liu, Jinyu; Xu, Yun; Li, Jianlang

    2015-11-01

    An azimuthally polarized and passively Q-switched ytterbium-doped fiber laser was demonstrated. With the involvement of a single lens inside the laser resonator, a birefringent crystal was used as the polarization discriminator, and a Cr4+:YAG crystal acted as the saturable absorber and also the output coupler. For the simplicity and low optical loss of the resonator cavity, this fiber laser emitted azimuthally polarized pulse with a high slope efficiency of 72.6% and high average power of 4.11 W. The laser pulse had 132-ns duration and 112-kHz repetition rate at the absorbed pump power of 6.40 W.

  14. VCSEL end-pumped passively Q-switched Nd:YAG laser with adjustable pulse energy.

    PubMed

    Goldberg, Lew; McIntosh, Chris; Cole, Brian

    2011-02-28

    A compact, passively Q-switched Nd:YAG laser utilizing a Cr4+:YAG saturable absorber, is end-pumped by the focused emission from an 804 nm vertical-cavity surface-emitting laser (VCSEL) array. By changing the VCSEL operating current, we demonstrated 2x adjustability in the laser output pulse energy, from 9 mJ to 18 mJ. This energy variation was attributed to changes in the angular distribution of VCSEL emission with drive current, resulting in a change in the pump intensity distribution generated by a pump-light-focusing lens. PMID:21369256

  15. The passive Q-switching regime in a solid state laser with a multiloop cavity

    NASA Astrophysics Data System (ADS)

    Pogoda, A. P.; Burkovskii, G. V.; Makarchuk, P. S.; Khakhalin, I. S.; Boreisho, A. S.; Fedin, A. V.

    2016-03-01

    A compact, pulsed-periodic YAG: Nd3+ laser with self-pumped phase-conjugate multiloop cavity and passive Q-switching by YAG: Cr 4+ and GSGG: Cr 4+ crystals has been studied. It is established that the energy and temporal parameters of radiation in separate pulses of a periodic train can be controlled almost without changing the pulse train energy. A regime of generating modulated radiation pulses with a peak power of up to 30 MW and a spatial brightness of 1.7 × 1015 W/(cm2 sr) at a radiation beam quality parameter of M 2 < 1.2 has been realized in experiment.

  16. High-peak-power single-oscillator actively Q-switched mode-locked Tm3+-doped fiber laser and its application for high-average output power mid-IR supercontinuum generation in a ZBLAN fiber.

    PubMed

    Kneis, Christian; Donelan, Brenda; Manek-Hönninger, Inka; Robin, Thierry; Cadier, Benoît; Eichhorn, Marc; Kieleck, Christelle

    2016-06-01

    A single-oscillator actively Q-switched mode-locked (QML) thulium-doped silica fiber laser is presented and used to pump a ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) fiber for mid-infrared (mid-IR) supercontinuum (SC) generation. The fiber laser provided high-peak-power levels directly from the oscillator delivering single mode-locked pulse energies up to 48 μJ, being 2-4 orders of magnitude higher than conventional continuous wave mode-locked lasers. By pumping a ZBLAN fiber specially designed for high-output-power SC generation, 7.8 W have been achieved in all spectral bands with a spectrum extending to 4.2 μm. PMID:27244410

  17. Interaction and motion of solitons in passively-mode-locked fiber lasers

    SciTech Connect

    Liu, Xueming

    2011-11-15

    Interaction and motion of multiple solitons in passively-mode-locked (PML) fiber lasers are investigated numerically. Three types of relative motions of two solitons are found in PML fiber lasers. The numerical results show that the relative motion of solitons attributes to the phase shift, which corresponds to the instantaneous frequency at pulse peak to be nonzero. Different from the classical dynamics of billiard balls, the interaction of solitons is similar to the Feynman diagram which is a pictorial way to represent the interaction of particles. After solitons interact with one another, their shapes do not change, but their phases shift and relative motions change. The theoretical results demonstrate that the separation of neighboring solitons in the laser cavity is about several hundred picoseconds to several nanoseconds. The theoretical predictions are in good agreement with the experimental results.

  18. Tuning the external optical feedback-sensitivity of a passively mode-locked quantum dot laser

    NASA Astrophysics Data System (ADS)

    Raghunathan, R.; Grillot, F.; Mee, J. K.; Murrell, D.; Kovanis, V.; Lester, L. F.

    2014-07-01

    The external optical feedback-sensitivity of a two-section, passively mode-locked quantum dot laser operating at elevated temperature is experimentally investigated as a function of absorber bias voltage. Results show that the reverse-bias voltage on the absorber has a direct impact on the damping rate of the free-running relaxation oscillations of the optical signal output, thereby enabling interactive external control over the feedback-response of the device, even under the nearly resonant cavity configuration. The combination of high temperature operation and tunable feedback-sensitivity is highly promising from a technological standpoint, in particular, for applications requiring monolithic integration of multi-component architectures on a single chip in order to accomplish, for instance, the dual-objectives of stable pulse quality and isolation from parasitic reflections.

  19. Passively mode-locked fiber laser by a cell-type WS2 nanosheets saturable absorber

    PubMed Central

    Yan, Peiguang; Liu, Aijiang; Chen, Yushan; Wang, JinZhang; Ruan, Shuangchen; Chen, Hao; Ding, Jinfei

    2015-01-01

    A cell-type saturable absorber has been demonstrated by filling the single mode photonic crystal fiber (SMPCF) with tungsten disulfide (WS2) nanosheets. The modulation depth, saturable intensity, and non-saturable loss of this SA are measured to be 3.53%, 159 MW/cm2 and 23.2%, respectively. Based on this SA, a passively mode-locked EDF laser has been achieved with pulse duration of 808 fs and repetition rate of 19.57 MHz, and signal-noise-ratio (SNR) of 60.5 dB. Our results demonstrate that the cell-type WS2 nanosheets SA can serve as a good candidate for short-pulse mode locker. PMID:26213180

  20. A passively mode locked thulium doped fiber laser using bismuth telluride deposited multimode interference

    NASA Astrophysics Data System (ADS)

    Jung, M.; Lee, J.; Song, W.; Lee, Y. L.; Lee, J. H.; Shin, W.

    2016-05-01

    We proposed a multimode interference (MMI) fiber based saturable absorber using bismuth telluride at  ∼2 μm region. Our MMI based saturable absorber was fabricated by fusion splicing with single mode fiber and null core fiber. The MMI functioned as both wavelength fixed filter and saturable absorber. The 3 dB bandwidth and insertion loss of MMI were 42 nm and 3.4 dB at wavelength of 1958 nm, respectively. We have also reported a passively mode locked thulium doped fiber laser operating at a wavelength of 1958 nm using a multimode interference. A temporal bandwidth of  ∼46 ps was experimentally obtained at a repetition rate of 8.58 MHz.

  1. Passively mode-locked Yb:CaF2 thin-disk laser.

    PubMed

    Dannecker, Benjamin; Délen, Xavier; Wentsch, Katrin S; Weichelt, Birgit; Hönninger, Clemens; Voss, Andreas; Ahmed, Marwan Abdou; Graf, Thomas

    2014-09-22

    We report on the first demonstration of a passively (SESAM) mode-locked Yb:CaF(2) thin-disk laser operating at a repetition rate of 35 MHz with close to diffraction-limited beam quality (M(2) ≈ 1.1) at an average output power of up to 6.6 W. The optical efficiency was 15.3%. Nearly transform limited pulses with a duration of 445 fs and a spectral width of 2.6 nm at full width half maximum (FWHM) were obtained at the maximum output power. This corresponds to a pulse-energy of approximately 0.19 μJ and a peak-power of 0.4 MW. PMID:25321699

  2. Graphene-based passively mode-locked bidirectional fiber ring laser.

    PubMed

    Mamidala, Venkatesh; Woodward, R I; Yang, Y; Liu, H H; Chow, K K

    2014-02-24

    We present an all-fiber bidirectional passively mode-locked soliton laser with a graphene-based saturable absorber for the first time to the best of our knowledge. Our design includes a four-port circulator to introduce different sections of cavity for the two counter-propagating pulses, so they have distinct output characteristics. Simultaneous bidirectional operation is achieved by appropriately adjusting the net cavity birefringence and loss. In the clockwise direction, the laser emits ~750 fs pulses at 1561.6 nm, with a repetition rate of 7.68 MHz. In the counter clockwise direction, the central wavelength, pulse width, and repetition rate are 1561.0 nm, ~850 fs, and 6.90 MHz, respectively. PMID:24663774

  3. Passively Q-switched flashlamp pumped Nd:YAG laser using liquid graphene oxide as saturable absorber

    NASA Astrophysics Data System (ADS)

    Adnan, N. N.; Bidin, N.; Taib, N. A. M.; Haris, H.; Fakaruddin, M.; Hashim, A. M.; Krishnan, G.; Harun, S. W.

    2016-06-01

    The performance of passively Q-switched Nd:YAG laser operating at 1060 nm is demonstrated using liquid graphene oxide (GO) composite solution as saturable absorber for the first time. The Q-switched Nd:YAG laser is pumped by a xenon flashlamp. The GO was prepared using the simplified Hummer's method and then mixed with polyethylene oxide to form a composite solution. The Q-switched pulsed laser operates at wavelength of 1064.5 nm with a threshold pump energy of 33.64 J. The maximum output Q-switched laser energy of 41.6 mJ achieved at the maximum pump energy of 81 J. The corresponding pulse width is 98.67 ns.

  4. All solid-state cw passively mode-locked Ti:sapphire laser using a colored glass filter

    SciTech Connect

    Sarukura, N.; Ishida, Y.; Yanagawa, T.; Nakano, H. )

    1990-07-16

    All solid-state cw passive mode locking of a Ti:sapphire laser is accomplished using a colored glass filter, instead of an organic dye, as a saturable absorber. The tuning range is remarkably wide (785--855 nm), and 2.7 ps pulses are obtained directly from the cavity.

  5. Self-starting passively mode-locked tunable femtosecond Cr 4+:YAG laser using a saturable absorber mirror

    NASA Astrophysics Data System (ADS)

    Hayduk, M. J.; Johns, S. T.; Krol, M. F.; Pollock, C. R.; Leavitt, R. P.

    1997-02-01

    We have demonstrated self-starting, passive mode-locking of a Cr 4+:YAG laser using a saturable absorber mirror structure. Highly stable femtosecond pulses tunable from 1488 to 1535 nm were generated with average output powers ranging from 40 to 80 mW. Nearly transform limited pulses of 120 fs duration were obtained at 1488 nm.

  6. High-power femtosecond pulse generation in a passively mode-locked Nd:SrLaAlO4 laser

    NASA Astrophysics Data System (ADS)

    Liu, Shan-De; Dong, Lu-Lu; Zheng, Li-He; Berkowski, Marek; Su, Liang-Bi; Ren, Ting-Qi; Peng, Yan-Dong; Hou, Jia; Zhang, Bai-Tao; He, Jing-Liang

    2016-07-01

    A high optical quality Nd:SrLaAlO4 (Nd:SLA) crystal was grown using the Czochralski method and showed broad fluorescence spectrum with a full width at half maximum value of 34 nm, which is beneficial for generating femtosecond laser pulses. A stable diode-pumped passively mode-locked femtosecond Nd:SLA laser with 458 fs pulse duration was achieved for the first time at a central wavelength of 1077.9 nm. The average output power of the continuous-wave mode-locked laser was 520 mW and the repetition rate was 78.5 MHz.

  7. Coherence collapse in monolithic quantum-dash-based passive mode-locked lasers

    NASA Astrophysics Data System (ADS)

    Merghem, K.; Rosales, R.; Azouigui, S.; Martinez, A.; Van Dijk, F.; Aubin, G.; Ramdane, A.

    2010-04-01

    Monolithic semiconductor mode-locked lasers (MLLs) are rising considerable interest for such diverse applications as very high speed optical time division multiplexing sources (40-160 GHz), all-optical signal processing, and low noise sampling for signal monitoring of optical networks. In a large number of these applications, MLLs may be subjected to optical feedback generated by unwanted reflections in optical systems which may greatly degrade laser performance. A number of experimental studies have been performed to evaluate the sensitivity of MLLs to optical feedback showing an increase of phase noise [1-5]. Quantum-dash (Qdash) based Fabry Perot lasers have been shown to exhibit an improved tolerance to feedback [6]. In this work, optical feedback tolerance is investigated for a monolithic quantum-dash-based passive mode-locked laser emitting at 1.58 μm. The two-section device generates ~5 ps pulses at a repetition rate of 17 GHz. The onset of the coherence collapse (CC) regime is experimentally determined by measuring the broadening of the longitudinal modes in the optical spectrum. Depending on bias condition, the CC regime is reached for values of feedback ranging from -35 dB to -29 dB at which emitted pulses were slighly broadened. The radio-frequency (RF) linewidth was simultaneously assessed and a drastic reduction of the RF linewidth with increasing feedback strength is evidenced. This indicates a reduction of the phase noise, thus implying a low "high frequency" timing jitter. We in particular observed an RF linewidth narrowing down to a value of less than 1 kHz under optical feedback.

  8. Passive mode-locking of a diode-pumped Nd:YVO(4) laser by intracavity SHG in PPKTP.

    PubMed

    Iliev, Hristo; Chuchumishev, Danail; Buchvarov, Ivan; Petrov, Valentin

    2010-03-15

    Experimental results on passive mode-locking of a Nd:YVO(4) laser using intracavity frequency doubling in periodically poled KTP (PPKTP) crystal are reported. Both, negative cascaded chi((2)) lensing and frequency doubling nonlinear mirror (FDNLM) are exploited for the laser mode-locking. The FDNLM based on intensity dependent reflection in the laser cavity ensures self-starting and self-sustaining mode-locking while the cascaded chi((2)) lens process contributes to substantial pulse shortening. This hybrid technique enables generation of stable trains of pulses at high-average output power with several picoseconds pulse width. The pulse repetition rate of the laser is 117 MHz with average output power ranging from 0.5 to 3.1 W and pulse duration from 2.9 to 5.2 ps. PMID:20389592

  9. Continuous-wave and passively Q-switched Nd:LYSO lasers

    NASA Astrophysics Data System (ADS)

    Zhuang, S. D.; Xu, X. D.; Wang, Z. P.; Li, D. Z.; Yu, H. H.; Xu, J.; Guo, L.; Chen, L. J.; Zhao, Y. G.; Xu, X. G.

    2011-04-01

    Continuous-wave (CW) and passively Q-switched performance of a Nd-doped oyorthosilicate mixing crystal, (Nd0.005Lu0.4975Y0.4975)2SiO5 (Nd:LYSO), were reported. As a result, new dual-wavelength all-solid-state lasers at 1075 and 1079 nm were achieved. When the absorbed pump power was 3.87 W, the CW laser produced 1.1 W output, corresponding to an optical conversion efficiency of 28.4% and a slope efficiency of 32.4%. By using a Cr4+:YAG wafer as the saturable absorber, we achieved Q-switching operation of Nd:LYSO crystal. The maximal average output power, shortest pulse width, largest pulse energy and highest peak power were measured to be 294 mW, 27.5 ns, 34.3 μJ and 1.18 kW, respectively. By difference frequency, these dual-wavelength lasers have potential applications for the generation of a broadband coherent radiation from 0.7-1.3 THz.

  10. Diode-end-pumped passively mode-locked high-power Nd:YVO4 laser with a relaxed saturable Bragg reflector.

    PubMed

    Chen, Y F; Tsai, S W; Lan, Y P; Wang, S C; Huang, K F

    2001-02-15

    We demonstrate a high-power passively mode-locked Nd:YVO (4) laser that uses a saturable Bragg reflector (SBR) with strain relaxation. 23.5 W of average power with ~21.5-ps cw mode-locked pulse trains was generated at a 50-W pump power. Experimental results show that appropriate strain relaxation in the SBR makes the mode-locking operation less sensitive to temperature variation. PMID:18033546

  11. Pulse bundles and passive harmonic mode-locked pulses in Tm-doped fiber laser based on nonlinear polarization rotation.

    PubMed

    Wang, Xiong; Zhou, Pu; Wang, Xiaolin; Xiao, Hu; Liu, Zejin

    2014-03-10

    We demonstrate the nanosecond-level pulses in Tm-doped fiber laser generated by passively harmonic mode-locking. Nonlinear polarization rotation performed by two polarization controllers (PCs) is employed to induce the self-starting harmonic mode-locking. The fundamental repetition rate of the laser is 448.8 kHz, decided by the length of the cavity. Bundles of pulses with up to 17 uniform subpulses are generated due to the split of pulse when the pump power increases and the PCs are adjusted. Continuous harmonic mode-locked pulse trains are obtained with 1st to 6th and even more than 15th order when the positions of the PCs are properly fixed and the pump power is scaled up. The widths of all the uniform individual pulses are mostly 3-5 ns, and pulse with width of 304 ns at fundamental repetition rate can also be generated by adjusting the PCs. Hysteresis phenomenon of the passively harmonic mode-locked pulses' repetition frequency versus pump power is observed. The rather wide 3dB spectral bandwidth of the pulse train (25 nm) indicates that they may resemble noise-like pulses. PMID:24663948

  12. Radially polarized and pulsed output from passively Q-switched Nd:YAG ceramic microchip laser.

    PubMed

    Li, Jian-lang; Ueda, Ken-ichi; Musha, Mitsuru; Zhong, Lan-xiang; Shirakawa, Akira

    2008-11-15

    For the first time, to the best of our knowledge, a radially polarized laser pulse was produced from a passively Q-switched Nd:YAG ceramic microchip laser with a piece of Cr4+:YAG crystal as the saturable absorber and multilayer concentric subwavelength grating as the polarization-selective output coupler. The averaged laser power reached 450 mW with a slope efficiency of 30.2%. The laser pulse had a maximum peak power of 759 W, a minimum pulse duration of 86 ns, and a 6.7 kHz repetition rate at 3.7 W absorbed pump power. The polarization degree of the radially polarized pulse was measured to be as high as 97.4%. Such a radially polarized laser pulse with a high peak power and a short width is important to numerous applications such as metal cutting. PMID:19015709

  13. Diode-side-pumped, passively Q-switched Yb:LuAG laser

    NASA Astrophysics Data System (ADS)

    Kaskow, Mateusz; Galecki, Lukasz; Jabczynski, Jan K.; Skorczakowski, Marek; Zendzian, Waldemar; Sulc, Jan; Nemec, Michal; Jelinkova, Helena

    2015-10-01

    A high-gain, diode-side-pumped Yb:LuAG slab laser was designed and investigated for use at room temperature. Pumping occurred from a fast-axis collimated 2D laser diode stack emitting at a wavelength of 970 nm, with 0.8 J over a duration of 0.8 ms. The pump scheme, which enabled efficient mode matching and high gain, was analysed and experimentally verified for different dopant levels. An energy of 100 mJ with 23% slope efficiency in a near fundamental mode was achieved in the free-running regime. A peak power of 2.5 MW and a pulse energy of 10.1 mJ were demonstrated in passive Q-switching by means of a Cr:YAG saturable absorber with 39% initial transmission. The study defined the indications for optimizing such a system.

  14. Passively Q-switched Nd:YAG ceramic microchip laser with azimuthally polarized output

    NASA Astrophysics Data System (ADS)

    Li, J.-L.; Lin, D.; Zhong, L.-X.; Ueda, K.; Shirakawa, A.; Musha, M.; Chen, W.-B.

    2009-10-01

    A passively-Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) ceramic microchip laser was demonstrated to emit azimuthally polarized beam bus using a chromium-doped YAG (Cr4+:YAG) crystal as saturable absorber and a multilayer concentric subwavelength grating as polarization-selective output coupler. The laser's output power reached 512 mW with an initial slope efficiency of nearly 60%, and the pulse had 1.15-kW peak power with 40-ns duration and 11-kHz repetition rate at 3.9-W absorbed pump power. The laser beam's polarization degree was 97.6%. The thermal lensing effect in Nd:YAG microchip remained as a problem to be solved.

  15. Compact, passively Q-switched Nd:YAG laser for the MESSENGER mission to Mercury.

    PubMed

    Krebs, Danny J; Novo-Gradac, Anne-Marie; Li, Steven X; Lindauer, Steven J; Afzal, Robert S; Yu, Anthony W

    2005-03-20

    A compact, passively Q-switched Nd:YAG laser has been developed for the Mercury Laser Altimeter, an instrument on the Mercury Surface, Space Environment, Geochemistry, and Ranging mission to the planet Mercury. The laser achieves 5.4% efficiency with a near-diffraction-limited beam. It passed all space-flight environmental tests at subsystem, instrument, and satellite integration testing and successfully completes a postlaunch aliveness check en route to Mercury. The laser design draws on a heritage of previous laser altimetry missions, specifically the Ice Cloud and Elevation Satellite and the Mars Global Surveyor, but incorporates thermal management features unique to the requirements of an orbit of the planet Mercury. PMID:15813276

  16. A high repetition rate passively Q-switched microchip laser for controllable transverse laser modes

    NASA Astrophysics Data System (ADS)

    Dong, Jun; Bai, Sheng-Chuang; Liu, Sheng-Hui; Ueda, Ken-Ichi; Kaminskii, Alexander A.

    2016-05-01

    A Cr4+:YAG passively Q-switched Nd:YVO4 microchip laser for versatile controllable transverse laser modes has been demonstrated by adjusting the position of the Nd:YVO4 crystal along the tilted pump beam direction. The pump beam diameter-dependent asymmetric saturated inversion population inside the Nd:YVO4 crystal governs the oscillation of various Laguerre-Gaussian, Ince-Gaussian and Hermite-Gaussian modes. Controllable transverse laser modes with repetition rates over 25 kHz and up to 183 kHz, depending on the position of the Nd:YVO4 crystal, have been achieved. The controllable transverse laser beams with a nanosecond pulse width and peak power over hundreds of watts have been obtained for potential applications in optical trapping and quantum computation.

  17. Variable energy, high peak power, passive Q-switching diode end-pumped Yb:LuAG laser

    NASA Astrophysics Data System (ADS)

    Kaskow, M.; Sulc, J.; Jabczynski, J. K.; Jelinkova, H.

    2014-12-01

    A new method to control the pulse energy in a passively Q-switched laser was proposed and experimentally verified for a diode-end-pumped Yb:LuAG laser. By changing the pumping area parameters it was possible to demonstrate generation of a wide range of output energies with a single laser configuration consisting of a gain medium, passive Q-switch and out-coupling mirror. The range of available energies 0.15-0.51 mJ with maximum peak power of 113 kW in simple Q-switching regime by means of a Cr:YAG saturable absorber and a Yb:LuAG gain medium pumped by a 20 W laser diode emitting at 968 nm was demonstrated.

  18. Highly efficient passively Q-switched Tm,Ho:GdVO4 laser with kilowatt peak power

    NASA Astrophysics Data System (ADS)

    Du, Yanqiu; Yao, Baoquan; Liu, Wei; Cui, Zheng; Duan, Xiaoming; Ju, Youlun; Yu, Hong

    2016-04-01

    We present the experimental results on the laser characteristics of diode-pumped passively Q-switched Tm,Ho:GdVO4 and Tm,Ho:YVO4 lasers with a Cr2+:ZnS saturable absorber emitting in the 2-μm range. The Tm,Ho:GdVO4 laser exhibits better performance than the Tm,Ho:YVO4 laser. The minimum pulse duration of 32.7 ns is obtained with the pulse energy of 0.30 mJ, corresponding to the peak power of 9.1 kW. The slope efficiencies of continuous wave and passively Q-switched Tm,Ho:GdVO4 lasers are 49.9% and 36.5%, corresponding to the Q-switching efficiency of 70.2%.

  19. Modeling and analysis of distributed feedback quantum dot passively mode-locked lasers.

    PubMed

    Rahimi, Javad; Ahmadi, Vahid; Yavari, Mohammad Hasan

    2016-07-01

    In this paper, we investigate numerically two proposed monolithic distributed feedback quantum dot passively mode-locked lasers (DFB-QDMLLs) with and without gratings in the saturable absorber (SA) section in order to enhance two important performances of QDMLLs for ultrahigh-bit-rate and single-mode applications. We find out that depending on the length of the grating, optical pulses with durations of about 3-8 ps at approximately 2nd and 4th harmonics of cavity round-trip frequencies can be generated by the proposed structures. We also compare the temporal and spectral behaviors of these structures under specified bias conditions and SA lengths. It is shown that DFB-QDMLLs have the ability to generate optical pulses with more peak power than grating-embedded saturable absorber (GESA-DFB-QDMLL) structures which generate shorter pulses with narrower spectral bandwidths. We also show that DFB-QDMLLs operate in a larger range of absorber voltages while the other structure is very sensitive to absorber voltage and operates well for middle ranges of this parameter. PMID:27409197

  20. Single-walled carbon nanotube passively mode-locked O-band Raman fiber laser

    NASA Astrophysics Data System (ADS)

    Steinberg, D.; Saito, L. A. M.; Rosa, H. G.; Thoroh de Souza, E. A.

    2016-05-01

    We present a detailed analysis of a nanosecond-pulse single-walled carbon nanotube (SWCNT) passively mode-locked O-band Raman fiber lasers. As gain medium, single mode fiber (SMF) and highly nonlinear Raman gain were used at three different experimental setups. By incorporating 1.0 nm mean diameter SWCNT as saturable absorbers (SA) at 2.3 km SMF long-length gain medium setup, soliton-like spectrum followed by nanosecond high chirped pulse was observed at cavity fundamental repetition rate. In order to shorter the chirped pulse, intracavity anomalous dispersion was introduced with normal dispersion shift fiber (DSF) lengths and pulse duration decreased from 4.20 to 2.30 ns. By using highly nonlinear Raman gain medium in the O-band Raman laser configuration, the laser generated clean and well-defined nanosecond high chirped pulses, achieving pulse duration as short as 2.30 ns with 230 m gain medium length. Also, we could estimate the picosecond pulse duration region as a function of gain medium length of this laser and compared with SMF pulse shortening curve. As results, the lasers presented similar tendencies, indicating a strong influence of nonlinearities and dispersion in the pulse duration shortening.

  1. Output Power Limitations and Improvements in Passively Mode Locked GaAs/AlGaAs Quantum Well Lasers

    PubMed Central

    Tandoi, Giuseppe; Ironside, Charles N.; Marsh, John H.; Bryce, A. Catrina

    2013-01-01

    We report a novel approach for increasing the output power in passively mode locked semiconductor lasers. Our approach uses epitaxial structures with an optical trap in the bottom cladding that enlarges the vertical mode size to scale the pulse saturation energy. With this approach we demonstrate a very high peak power of 9.8 W per facet, at a repetition rate of 6.8 GHz and with pulse duration of 0.71 ps. In particular, we compare two GaAs/AlGaAs epilayer designs, a double quantum well design operating at 830 nm and a single quantum well design operating at 795 nm, with vertical mode sizes of 0.5 and 0.75 μm, respectively. We show that a larger mode size not only shifts the mode locking regime of operation towards higher powers, but also produces other improvements in respect of two main failure mechanisms that limit the output power: the catastrophic optical mirror damage and the catastrophic optical saturable absorber damage. For the 830 nm material structure, we also investigate the effect of non-absorbing mirrors on output power and mode locked operation of colliding pulse mode locked lasers. PMID:23843678

  2. Passive Q-switching of an all-fiber laser induced by the Kerr effect of multimode interference.

    PubMed

    Fu, Shijie; Sheng, Quan; Zhu, Xiushan; Shi, Wei; Yao, Jianquan; Shi, Guannan; Norwood, R A; Peyghambarian, N

    2015-06-29

    A novel passively Q-switched all-fiber laser using a single mode-multimode-single mode fiber device as the saturable absorber based on the Kerr effect of multimode interference is reported. Stable Q-switched operation of an Er(3+)/Yb(3+) co-doped fiber laser at 1559.5 nm was obtained at a pump power range of 190-510 mW with the repetition rate varying from 14.1 kHz to 35.2 kHz and the pulse duration ranging from 5.69 μs to 3.86 μs. A maximum pulse energy of 0.8 μJ at an average output power of 27.6 mW was achieved. This demonstrates a new modulation mechanism for realizing Q-switched all-fiber laser sources. PMID:26191734

  3. Generation of stable high order harmonic noise-like pulses in a passively mode-locked double clad fiber ring laser

    NASA Astrophysics Data System (ADS)

    Hernandez-Garcia, J. C.; Pottiez, O.; Ibarra-Escamilla, B.; Estudillo-Ayala, J. M.; Rojas-Laguna, R.; Kuzin, E.; Muñoz-Lopez, A.; Filoteo-Razo, J. D.

    2015-03-01

    We study a passively mode-locked double-clad Erbium-Ytterbium fiber ring laser producing noise-like pulse through nonlinear polarization evolution and polarization selection. Single noise-like pulsing is only observed at moderate pump power. As pump power is increased, and through polarization controllers adjustments, harmonic mode-locking of growing order were successively appearing. For pump powers close to the damage threshold of the setup, we reach harmonic orders beyond 1200 and repetition frequencies in excess of a quarter of a GHz. Finally, these experimental results could be useful in the quest for higher pulse energies and higher repetition rates in passively mode-locked fiber lasers.

  4. Laser diode and pumped Cr:Yag passively Q-switched yellow-green laser at 543 nm

    NASA Astrophysics Data System (ADS)

    Yao, Y.; Ling, Zhao; Li, B.; Qu, D. P.; Zhou, K.; Zhang, Y. B.; Zhao, Y.; Zheng, Q.

    2013-03-01

    Efficient and compact yellow green pulsed laser output at 543 nm is generated by frequency doubling of a passively Q-switched end diode-pumped Nd:YVO4 laser at 1086 nm under the condition of sup-pressing the higher gain transition near 1064 nm. With 15 W of diode pump power and the frequency doubling crystal LBO, as high as 1.58 W output power at 543 nm is achieved. The optical to optical conversion efficiency from the corresponding Q-switched fundamental output to the yellow green output is 49%. The peak power of the Q-switched yellow green pulse laser is up to 30 kW with 5 ns pulse duration. The output power stability over 8 hours is better than 2.56% at the maximum output power. To the best of our knowledge, this is the highest watt-level laser at 543 nm generated by frequency doubling of a passively Q-switched end diode pumped Nd:YVO4 laser at 1086 nm.

  5. Development of monolith Nd:YAG /Cr+4:YAG passively Q-switched microchip laser

    NASA Astrophysics Data System (ADS)

    Izhnin, Ihor; Vakiv, Mykola; Izhnin, Aleksandr; Syvorotka, Igor; Ubizskii, Sergii; Syvorotka, Ihor, Jr.

    2005-09-01

    The main features of passively Q-switched microchip lasers development are considered. The active medium of laser is an epitaxial structure combining an epitaxial layer of saturable absorber Cr4+:Y3Al5O12 (Cr:YAG) grown on substrate of generating crystal Nd:YAG by liquid phase epitaxy. The modulator layer has an initial optical absorption of 36 cm-1 at wavelength of lasing (1064 nm). The epitaxial layer grown on unworking side was mechanically removed and this substrate side was optically polished. The other one was processed precisely to needed thickness. The cavity's mirrors were deposited by electron beam technique directly on each side of the structure to form a rugged, monolithic resonator. Diode laser Model ATC-C4000 with lasing wavelength 808 nm provided the CW end pumping. The output pulses parameters were investigated by means of test bench consisting of photoelectric transducer FEK-15 and Digital Phosphor Oscilloscope TDS 5052B. The obtained laser parameter are as follows: pulse width (FWHM) about 1.3 ns, repetition rate 5.5 kHz, average output power about 10 mW, pulse energy 1.0 μJ, pick power 1.2 kW. The possible solutions for laser parameter improving and optimization are discussed.

  6. High-power passively Q-switched Nd:KGW laser pumped at 877 nm

    NASA Astrophysics Data System (ADS)

    Huang, K.; Ge, W. Q.; Zhao, T. Z.; Feng, C. Y.; Yu, J.; He, J. G.; Xiao, H.; Fan, Z. W.

    2016-06-01

    In this work, we demonstrate, for the first time, a high-power passively Q-switched Ng-cut Nd3+:KGd(WO4)2/Cr4+:YAG laser pumped at 877 nm. The maximum average output power of ~1.6 W is obtained at the pump power of 5.22 W, when a saturable absorber with 98 % of initial transmission is used. The corresponding pulse energy is up to 16 µJ. The maximum pulse energy of 25.3 µJ is achieved at a repetition rate of 59 kHz, by employing a saturable absorber with 95 % of initial transmission. The corresponding pulse width and average output power are 89.0 ns and 1.5 W, respectively. A careful cavity design and a good thermal management ensure nearly TEM00 output with M 2 ≤ 1.22 within the whole range of operation in both N p and N m directions at 877 nm pump.

  7. Passively Q-switched Ho:YLF laser pumped by Tm3+-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Ju, Youlun; Yao, Baoquan; Dai, Tongyu; Duan, Xiaoming; Li, Jiang; Ding, Yu; Liu, Wei; Pan, Yubai; Li, Chaoyu

    2016-03-01

    We demonstrate a compact and efficient passively Q-switched (PQS) Ho:YLF laser pumped by a self-made all-fiber laser. Firstly, we design and make an all-fiber laser operating at 1940 nm with a slope efficiency of 40.6%. Then, the all-fiber laser was used to pump Ho:YLF laser directly. In the CW (continues-wave) operation Ho:YLF laser, the maximum output power was 7.79 W, corresponding to the slope efficiency of 55.2%. Using Cr2+:ZnS as the saturable absorber, the average power of 6.03 W was achieved with the slope efficiency of 45.9%. The shortest pulse duration was 15.6 ns and the pulse repetition frequency was 2.3 kHz at the pump power of 20.4 W. The pulse energy was a constant as 2.7 mJ when the pump power exceeded 15 W. The beam quality factor of M2 was 1.05, indicating nearly diffraction limited beam propagation.

  8. Analysis of mode wavefront characteristics for passively Q-switched slab Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Zhang, Xiang; Wang, Jie; Hu, Zhiqiu; Su, Likun

    2016-01-01

    The eigenmode of resonators with symmetric circular mirrors used in solid-state lasers is investigated. Further experiments on output beam quality on a passive Q-switched zigzag slab Nd:YAG laser have been performed by adopting Hartmann-Shack and Zernike-mode reconstruction methods. By the means of peak-valley and root mean square errors of the wavefront distribution, each order of Zernike aberrations are achieved accurately. Moreover, the distribution of circle energy in the far-field and corresponding beam evaluation factors can also be obtained by further calculation. Experimental results indicate that the wavefront aberration is mainly concentrated in the first 10 Zernike aberrations, which mainly includes the defocus Z3, the low-order astigmatism Z5, the coma aberration Z6, and the spherical aberration Z10, because of the crystal thermal effect and the intracavity phase perturbation. The method can be used to further analyze the compensation of intracavity aberration and optimal design for such lasers.

  9. Passive mode locking of a diode-pumped hybrid neodymium:glass and neodymium:yttrium orthovanadate lasers

    NASA Astrophysics Data System (ADS)

    Tachatraiphop, Sukanya

    In this thesis, I present the first experimental results of the passive mode locking of diode pumped hybrid Nd:glass and Nd:YVO4 lasers with weakly and strongly inhomogeneously broadened laser media: Nd:phosphate glass or Nd:silicate glass, respectively. The spectral and temporal characteristics of the mode-locked hybrid lasers are studied in term of the pump ratio and the gain peak separation of the two hybrid laser media. The mode-locked hybrid laser performance and behavior can be explained by using unsaturated and saturated gain profile in the free running state. The gain profile of the hybrid laser is controlled by the Nd:YVO4 gain via gain combination and cross saturated gain. To verify the accuracy of the numerical results, the cw hybrid laser experiment is conducted. Both simulation and experimental results show that, in both free running state and mode locking state, the spectral component of a hybrid laser is controlled by the Nd:YVO4 gain. With a proper pump of Nd:YVO4, the saturated gain profile of the hybrid laser is wider than that of Nd:glass laser. Un-smooth and narrower gain profile results by an excessive pump at Nd:YVO4. The gain narrowing effect is magnified when gain peaks of hybrid laser are overlap. Un-smooth and narrow gain profile increase mode locking instability and produce longer pulses. In the picosecond regime, the pulse duration is limited by recovery time of the saturable absorber. In the picosecond regime, the hybrid Nd:phosphate glass and Nd:YVO4 laser can mode lock at either 1054 nm or 1064 nm. Because of the soliton mechanism, the pulses can be generated in the femtosecond regime. With a strong soliton force, the wider and flatter gain profile of the hybrid laser can be utilized. The improvement of the hybrid laser performance is enhanced with a smaller negative GVD and strong pump power of Nd:glass media. In the femtosecond regime, the hybrid Nd:silicate glass and Nd:YVO 4 laser generates a shorter pulse duration and better

  10. Doubly passively Q-switched Yb:NaY(WO4)2 laser with dual-wavelength phenomenon

    NASA Astrophysics Data System (ADS)

    Lan, Ruijun

    2015-06-01

    A diode pumped doubly passively Q-switched \\text{Yb:NaY}≤ft(\\text{W}{{\\text{O}}4}\\right)2/\\text{C}{{\\text{r}}4+}\\text{:YAG}/\\text{GaAs} laser was realized for the first time to our knowledge. Compared with the singly passively Q-switched \\text{Yb:NaY}≤ft(\\text{W}{{\\text{O}}4}\\right)2/\\text{C}{{\\text{r}}4+}\\text{:YAG} laser, this laser can generate a higher repetition rate, and more symmetric and shorter pulses. The highest repetition rate and shortest pulse width was measured to be 82 kHz and 6 ns. At certain pump power, 1022 and 1026 nm dual-wavelength lasers were obtained, and the mechanism of this phenomenon was discussed.

  11. Highly efficient passively Q-switched Yb:YAG microchip lasers under high intensity laser-diode pumping

    NASA Astrophysics Data System (ADS)

    Dong, J.; Wang, G. Y.; Cheng, Y.

    2013-03-01

    A highly efficient Cr4+:YAG passively Q-switched Yb:YAG microchip laser has been demonstrated at room temperature by high-brightness single-emitter laser-diode pumping. The maximum average output power of 1.53 W was obtained at the absorbed pump power of 3.5 W. The optical-to-optical efficiency was 44% with respect to the absorbed pump power. Laser pulses with a pulse width of 2.9 ns, pulse energy of 11.3 μJ, and peak power of 3.9 kW were obtained. The high pump power intensity from a high-brightness single-emitter laser-diode plays an important role in the alleviation of thermal effects and the efficient performance of Cr4+:YAG passively Q-switched Yb:YAG microchip lasers.

  12. Watt-level passively Q-switched heavily Er(3+)-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror.

    PubMed

    Shen, Yanlong; Wang, Yishan; Luan, Kunpeng; Huang, Ke; Tao, Mengmeng; Chen, Hongwei; Yi, Aiping; Feng, Guobin; Si, Jinhai

    2016-01-01

    A diode-cladding pumped mid-infrared passively Q-switched Er(3+)-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 μm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail. PMID:27225029

  13. Passively Q-switched erbium-doped fiber laser using Fe3O4-nanoparticle saturable absorber

    NASA Astrophysics Data System (ADS)

    Bai, Xuekun; Mou, Chengbo; Xu, Luxi; Wang, Shaofei; Pu, Shengli; Zeng, Xianglong

    2016-04-01

    We experimentally demonstrate passively Q-switched erbium-doped fiber laser (EDFL) operation using a saturable absorber (SA) based on Fe3O4 nanoparticles (FONPs). As a type of transition metal oxide, the FONPs have a large nonlinear optical response and fast response time. The FONP-based SA possesses a modulation depth of 8.2% and nonsaturable absorption of 56.6%. Stable passively Q-switched EDFL pulses with an output pulse energy of 23.76 nJ, a repetition rate of 33.3 kHz, and a pulse width of 3.2 µs were achieved when the input pump power was 110 mW. The laser features a low threshold pump power of ∼15 mW.

  14. Watt-level passively Q-switched heavily Er3+-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror

    PubMed Central

    Shen, Yanlong; Wang, Yishan; Luan, Kunpeng; Huang, Ke; Tao, Mengmeng; Chen, Hongwei; Yi, Aiping; Feng, Guobin; Si, Jinhai

    2016-01-01

    A diode-cladding pumped mid-infrared passively Q-switched Er3+-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 μm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail. PMID:27225029

  15. Watt-level passively Q-switched heavily Er3+-doped ZBLAN fiber laser with a semiconductor saturable absorber mirror

    NASA Astrophysics Data System (ADS)

    Shen, Yanlong; Wang, Yishan; Luan, Kunpeng; Huang, Ke; Tao, Mengmeng; Chen, Hongwei; Yi, Aiping; Feng, Guobin; Si, Jinhai

    2016-05-01

    A diode-cladding pumped mid-infrared passively Q-switched Er3+-doped ZBLAN fiber laser with an average output power of watt-level based on a semiconductor saturable absorber mirror (SESAM) is demonstrated. Stable pulse train was produced at a slope efficiency of 17.8% with respect to launched pump power. The maximum average power of 1.01 W at a repetition rate of 146.3 kHz was achieved with a corresponding pulse energy of 6.9 μJ, from which the maximum peak power was calculated to be 21.9 W. To the best of our knowledge, the average power and the peak power are the highest in 3 μm region passively Q-switched fiber lasers. The influence of gain fiber length on the operation regime of the fiber laser has been investigated in detail.

  16. CONTROL OF LASER RADIATION PARAMETERS: Passive Q switching of a neodymium laser by a Cr4+ : YAG crystal switch

    NASA Astrophysics Data System (ADS)

    Il'ichev, Nikolai N.; Gulyamova, E. S.; Pashinin, Pavel P.

    1997-11-01

    Theoretical and experimental investigations were made of passive Q switching of a neodymium laser by a Cr4+ : YAG switch. Analytic expressions were derived for estimating the output energy of the TEM00 mode of a passively Q-switched laser from the known parameters of the Cr4+ : YAG switch, of the active element, and of the cavity. The adopted description makes it possible to cover the range from generation of the first spike of a free-running transient to generation of a giant pulse. An experimental study was made of the dependence of the output energy on the cavity parameters, on the material of the active element (in this investigation it was Nd :YAG and Cr, Nd : GSGG), and on the angle of rotation of the Cr4+ : YAG switch. The experimental results obtained agreed to within 30% with calculations.

  17. Cr{sup 4+}:YAG as passive Q-switch and Brewster plate in a pulsed Nd:YAG laser

    SciTech Connect

    Shimony, Y.; Burshtein, Z.; Kalisky, Y.

    1995-10-01

    The authors demonstrate the performance of a Nd:YAG laser, passively Q-switched with a Cr{sup 4+}:YAG plate, which plays the double role of a passive Q-switch ad a Brewster plate. The Brewster plate configuration contributes an intracavity loss of approximately 3.2 {times} 10{sup {minus}3} cm{sup {minus}1} along the cavity length. Losses contributed by the active Cr{sup 4+} ions in the plate relate to their excited state absorption. A freshly measured transmission saturation curve of Cr{sup 4+}:YAG suggests a ground state absorption cross section {sigma}{sub gs} = (8.7 {+-} 0.8) {times} 10{sup {minus}19} cm{sup 2}, and an excited state absorption cross section {sigma}{sub es} = (2.2 {+-} 0.2) {times} 10{sup {minus}19} cm{sup 2} of the Cr{sup 4+} ions at {lambda} = 1,064 nm.

  18. A continuous-wave and passively Q-switched Nd:LaGGG laser at 937 nm

    NASA Astrophysics Data System (ADS)

    Li, Z.-Y.; Ying, H.-Y.; Yang, H.; He, J.-L.

    2013-10-01

    A diode-end-pumped continuous-wave (CW) and passively Q-switched Nd:LaGGG (GGG: gadolinium gallium garnet) laser at about 937 nm was demonstrated for the first time. The maximum CW output power of 540 mW was obtained with the optical-optical conversion efficiency of 3.2% and the slope efficiency of 4.4%. A V3+:YAG (yttrium aluminum garnet) saturable absorber with the initial transmission of 97% was used for the passive Q-switching regime. The shortest pulse width was achieved as 500 ns with the pulse repetition rate of 96 kHz. The corresponding single-pulse energy and pulse peak power were determined as 1.56 μJ and 3.12 W, respectively.

  19. On the possibility of increasing the pulse energy of a passively Q-switched erbium glass minilaser

    SciTech Connect

    Izyneev, A A; Sadovskii, Pavel I; Sadovskii, S P

    2010-08-03

    A simple method to increase the output energy of a passively Q-switched erbium glass laser is proposed. Using the amplitude modulation of losses at the active element face, the fundamental mode was reliably suppressed and the laser operated in a selected higher-order mode. The output energy was experimentally increased by a factor of 2.1, and the range of allowable pump energy instability was extended threefold. (lasers)

  20. Comprehensive study of electro-optic and passive Q-switching in solid state lasers for altimeter applications

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Atul; Agrawal, Lalita; Pal, Suranjan; Kumar, Anil

    2006-12-01

    Laser Science and Technology Center (LASTEC), Delhi, is developing a space qualified diode pumped Nd: YAG laser transmitter capable of generating 10 ns pulses of 30 mJ energy @ 10 pps. This paper presents the results of experiments for comparative studies between electro-optic and passively Q-switched Nd: YAG laser in a crossed porro prism based laser resonator. Experimental studies have been performed by developing an economical bench model of flash lamp pumped Nd: YAG laser (rod dimension, \

  1. Passively Q-switched a-cut Nd:GdVO4 self-Raman laser with Cr:YAG

    NASA Astrophysics Data System (ADS)

    Peng, J. Y.; Zheng, Y.; Shi, Y. X.; Shen, J. P.

    2012-10-01

    A passively Q-switched a-cut Nd:GdVO4 self-Raman solid-state laser with Cr:YAG saturable absorber was firstly demonstrated. The first Stokes at 1173 nm was successfully obtained. At the maximum incident pump power, the pulse width was about 1.8 ns and the repetition rate was 27.5 kHz. 586.5 nm yellow laser output was also realized by use of an LBO frequency doubling crystal.

  2. Maximum value of the pulse energy of a passively Q-switched laser as a function of the pump power.

    PubMed

    Li, Jianlang; Ueda, Ken-ichi; Dong, Jun; Musha, Mitsuru; Shirakawa, Akira

    2006-07-20

    The finite recovery time Ts of the bleached absorber is presented as one of the possible mechanisms accounting for the increase-maximum-decrease in pulse energy E with the pumping rate Wp in cw-pumped passively Q-switched solid-state lasers, by analytically evaluating the sign of the derivative partial differentialE/ partial differentialWP. The results show that, in the low pump regime (T>Ts, T is the interpulse period), the initial population density ni remains constant, the final population density nf decreases with Wp, and this results in a monotonic increase of E with Wp. In the high pump regime (Tpassively Q switched by a Cr4+:YAG absorber is demonstrated to confirm this model. The theoretical model is also applied to the analysis of three previously reported passive Q switching solid-state [Nd:GdVO4, Nd+:LaSc3(BO3)4 (Nd+:LSB), and Nd:YAG] lasers experiments. PMID:16826274

  3. Fifty-ps Raman fiber laser with hybrid active-passive mode locking.

    PubMed

    Kuznetsov, A G; Kharenko, D S; Podivilov, E V; Babin, S A

    2016-07-25

    Actively mode locked Raman lasing in a ring PM-fiber cavity pumped by a linearly polarized Yb-doped fiber laser is studied. At co-propagating pumping, a stochastic pulse with duration defined by the AOM switching time (~15 ns) is generated with the round-trip period. At counter-propagating pumping, one or several sub-ns pulses (within the AOM switching envelope) are formed. It has been found that the formation of such stable multi-pulse structure is defined by the single-pulse energy limit (~20 nJ) set by the second-order Raman generation. Adding a NPE-based saturable absorber in the actively mode locked cavity, results in sufficient shortening of the generated pulses both in single- and multi-pulse regimes (down to 50 ps). A model is developed adequately describing the regimes. PMID:27464081

  4. Long cavity and low repetition rate passively mode-locked fiber laser with high-energy right angle trapezoid shaped soliton in anomalous dispersion regime

    NASA Astrophysics Data System (ADS)

    Luo, Wenfeng; Lv, Shuyuan; Zhao, Xiaoxia; Qiao, Dun

    2015-05-01

    A long cavity passively mode locked fiber laser in the anomalous dispersion regime is reported. Nonlinear polarization rotation technique is employed to achieve the mode locking in our experiments. The output pulse from the fiber laser has the Gaussian profile spectrum and right angle trapezoid shape. Stable mode locking is achieved without using any dispersion-compensation components. The single pulse with an energy of 652 nJ and a repetition rate of 836 kHz at the pump power of approximately 500 mW is obtained and the duration of the output pulse increases linearly with the pump power. Different from the conventional low-energy soliton pulse, experimental results demonstrate that the passively mode locked fiber laser operating in the anomalous regime can also realize high energy pulse.

  5. Control over the performance characteristics of a passively mode-locked erbium-doped fibre ring laser

    SciTech Connect

    Chernysheva, M A; Krylov, A A; Dianov, E M; Ogleznev, A A; Arutyunyan, N R; Pozharov, A S; Obraztsova, E D

    2013-08-31

    We report an all-fibre ultrashort pulse erbium-doped ring laser passively mode-locked by single-wall carbon nanotubes dispersed in carboxymethylcellulose-based polymer films. Owing to intracavity dispersion management and controlled absorption in the polymer films, the laser is capable of generating both femto- and picosecond pulses of various shapes in the spectral range 1.53 – 1.56 μm. We have demonstrated and investigated the generation of almost transform- limited, inversely modified solitons at a high normal cavity dispersion. (control of laser radiation parameters)

  6. Generation of 0. 7--0. 8. mu. picosecond pulses in an alexandrite laser with passive mode locking

    SciTech Connect

    Lisitsyn, V.N.; Matrosov, V.N.; Orekhova, V.P.; Pestryakov, E.V.; Sevast'yanov, B.K.; Trunov, V.I.; Zenin, V.N.; Remigailo, Y.L.

    1982-03-01

    Picosecond pulses of 0.7--0.8 ..mu.. wavelengths were generated in an alexandrite laser as a result of electronic--vibrational transitions /sup 4/T/sub 2/ ..-->.. /sup 4/A/sub 2/+h..omega../sub phonon/. Passive mode locking was ensured by the use of DS1 and DTTS saturable absorbers. The duration of the pulses generated using DS1 was 8 psec at wavelengths of 0.725--0.745 ..mu.., whereas the duration of the pulses generated using DTTS was 90 psec in the range 0.75--0.775 ..mu...

  7. Soliton collapse and bunched noise-like pulse generation in a passively mode-locked fiber ring laser

    NASA Astrophysics Data System (ADS)

    Tang, D. Y.; Zhao, L. M.; Zhao, B.

    2005-04-01

    A passively mode-locked soliton fiber ring laser with dispersion managed cavity is reported. The laser emits intense bunched noise-like pulses including the transform limited pulses. The optical spectrum of the laser emission has a bandwidth as broad as 32.10 nm. It was found that purely depending on the linear cavity phase delay the laser could be switched between the soliton operation and the noise-like pulse emission. Numerical simulations showed that the laser emission was caused by the combined effect of soliton collapse and positive cavity feedback in the laser.

  8. Soliton collapse and bunched noise-like pulse generation in a passively mode-locked fiber ring laser.

    PubMed

    Tang, D; Zhao, L; Zhao, B

    2005-04-01

    A passively mode-locked soliton fiber ring laser with dispersion managed cavity is reported. The laser emits intense bunched noise-like pulses including the transform limited pulses. The optical spectrum of the laser emission has a bandwidth as broad as 32.10 nm. It was found that purely depending on the linear cavity phase delay the laser could be switched between the soliton operation and the noise-like pulse emission. Numerical simulations showed that the laser emission was caused by the combined effect of soliton collapse and positive cavity feedback in the laser. PMID:19495118

  9. Single-frequency, 500-ns laser pulses generated by a passively Q-switched Nd laser

    NASA Astrophysics Data System (ADS)

    Jones, D. C.; Rockwell, D. A.

    1993-03-01

    Accounts are given of the construction and performance of a narrowband Q-switched oscillator that addresses requirements for heavy amplifier saturation as well as a degree of temporal pulse-shaping prior to oscillator beam injection into the amplifier chain that can avoid the severe temporal distortion imposed by amplifier saturation. This oscillator encompasses a lamp-pumped Cr:Nd:GSGG laser rod, a saturable absorber Q switch, and several etalon surfaces forming the output coupler. This device can be used in large baseline holography.

  10. A Cr4+:YAG passively Q-switched Nd:YVO4 microchip laser for controllable high-order Hermite–Gaussian modes

    NASA Astrophysics Data System (ADS)

    Dong, Jun; He, Yu; Bai, Sheng-Chuang; Ueda, Ken-ichi; Kaminskii, Alexander A.

    2016-09-01

    A nanosecond, high peak power, passively Q-switched laser for controllable Hermite–Gaussian (HG) modes has been achieved by manipulating the saturated inversion population inside the gain medium. The stable HG modes are generated in a Cr4+:YAG passively Q-switched Nd:YVO4 microchip laser by applying a tilted pump beam. The asymmetrical saturated inversion population distribution inside the Nd:YVO4 crystal for desirable HG modes is manipulated by choosing the proper pump beam diameter and varying pump power. A HG9,8 mode passively Q-switched Nd:YVO4 microchip laser with average output power of 265 mW has been obtained. Laser pulses with a pulse width of 7.3 ns and peak power of over 1.7 kW working at 21 kHz have been generated in the passively Q-switched Nd:YVO4 microchip laser.

  11. Passively Q-switched erbium-doped fiber laser at C-band region based on WS₂ saturable absorber.

    PubMed

    Ahmad, H; Ruslan, N E; Ismail, M A; Reduan, S A; Lee, C S J; Sathiyan, S; Sivabalan, S; Harun, S W

    2016-02-10

    We demonstrate a Q-switched erbium-doped fiber laser using tungsten disulfide (WS₂) as a saturable absorber. The WS₂ is deposited onto fiber ferrules using a drop-casting method. Passive Q-switched pulses operating in the C-band region with a central wavelength of 1560.7 nm are successfully generated by a tunable pulse repetition rate ranging from 27.2 to 84.8 kHz when pump power is increased from 40 to 220 mW. At the same time, the pulse width decreases from a maximum value of 3.84 μs to a minimum value of 1.44 μs. The signal-to-noise ratio gives a stable value of 43.7 dB. The modulation depth and saturation intensity are measured to be 0.99% and 36.2  MW/cm², respectively. PMID:26906366

  12. First demonstration of passively mode-locked Yb:CaF2 thin-disk laser

    NASA Astrophysics Data System (ADS)

    Dannecker, Benjamin; Délen, Xavier; Wentsch, Katrin S.; Weichelt, Birgit; Hönninger, Clemens; Voss, Andreas; Abdou Ahmed, Marwan; Graf, Thomas

    2015-02-01

    The need for ultra-short (sub-ps) pulsed laser systems with high power and high energy has advanced the mode-locked Ytterbium-doped thin-disk technology in the last decade. Therefore several research groups have made efforts to explore new laser crystals e.g. Yb:SSO, Yb:CAlGO or Yb:Lu2O3 for the generation of sub-500 fs pulses in thin-disk oscillators. Another promising and known candidate for ultra-short pulsed lasers is Yb:CaF2, which has been so far only used in bulk laser architecture. In this work, we present the first demonstration of a mode-locked Yb:CaF2 laser in thin-disk configuration. The resonator cavity was designed for eight passes through the disk per roundtrip at a repetition rate of 35 MHz. A saturable absorber mirror (SESAM) was used to obtain the soliton mode-locking. We achieved close-to transform-limited pulses with a pulse duration of less than 445 fs and an emission spectral width of 2.6 nm at FWHM (i.e. time-bandwidth product of 0.323). At the average output power of 6.6 W this corresponds to a peak-power of 430 kW and pulse energy of 190 nJ. To the best of our knowledge, this is the highest average output power and pulse energy using Yb:CaF2 as gain material reported to date. Taking into account the dispersion, self-phase modulation, pulse energy, output coupling ratio and laser gain, the pulse-duration estimated from the soliton-equation and our numerical calculations of pulse-propagation is in good agreement with the pulse-duration obtained in the experiment. Higher powers and shorter pulse-durations with this material are the subject of our future investigations.

  13. Experimental and theoretical studies of complex pulse evolutions in a passively mode-locked ring dye laser

    SciTech Connect

    Avramopoulos, H.; French, P.M.W.; Williams, J.A.R.; New, G.H.C.; Taylor, J.R. )

    1988-09-01

    The optimization of any femtosecond laser requires the various sources of frequency chirp to be taken into account. In particular, for a passively mode-locked CPM ring dye laser, the effects of group velocity dispersion and self-phase modulation arising from time-dependent absorption saturation and the optical Kerr effect must be considered. In this paper a detailed experimental and theoretical study has been made of the role of these parameters in a Rhodamine 110 CPM dye laser. Periodic pulse evolutions are observed, when both positive and negative frequency chirp are present, which are reminiscent of those governed by the nonlinear Schrodinger equation but which are, in fact, distinctly different. Similar results have been obtained with the standard Rhodamine 6G system and it is believed that the theoretical model is generally applicable to any passively mode-locked femtosecond dye laser. An important consequence of this work is that is permits the absolute value of the net group velocity dispersion in the laser cavity to be estimated.

  14. Dual-wavelength passively q-switched single-frequency fiber laser.

    PubMed

    Zhang, Yuanfei; Yang, Changsheng; Feng, Zhouming; Deng, Huaqiu; Peng, Mingying; Yang, Zhongmin; Xu, Shanhui

    2016-07-11

    We propose a compact dual-wavelength Q-switched single-frequency fiber laser based on a 17-mm-long home-made highly Er3+/Yb3+ co-doped phosphate fiber (EYDPF) and a semiconductor saturable absorber mirror (SESAM). The short cavity length and a polarization-maintaining fiber Bragg grating (PM-FBG) ensure that only one longitudinal mode is supported by each reflection peak. The maximum pulse energy of more than 34.5 nJ was realized with the shortest pulse duration of 110.5 ns and the Q-switched fiber laser has a repetition rate reaching over 700 kHz with a temporal synchronization of pulses at two wavelengths. Besides, the optical signal-to-noise ratio (OSNR) of larger than 64.5 dB was achieved. PMID:27410881

  15. Numerical Study of Passive Q Switching of a Tm:YAG Laser with a Ho:YLF Solid-State Saturable Absorber

    NASA Astrophysics Data System (ADS)

    Kuo, Yen-Kuang; Chang, Yi-An

    2003-03-01

    In a previous work [Appl. Phys. Lett. 65 , 3060 (1994) we experimentally demonstrated that passive ]Q switching of a 2017-nm, flashlamp-pumped Tm,Cr:YAG laser with a Ho:YLF saturable absorber could be obtained with an internal focusing lens. We numerically investigate the optical performance of the Ho:YLF Q -switched Tm:YAG laser system by solving the coupled rate equations. The simulation results indicate that the results obtained numerically are in good agreement with those obtained experimentally. With typical laser configuration, a Q -switched laser pulse of 35 mJ in 30 ns is obtained.

  16. Continuous-wave and passively Q-switched 1.06 μm ceramic Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    He, Ying; Ma, Yufei; Li, Jiang; Li, Xudong; Yan, Renpeng; Gao, Jing; Yu, Xin; Sun, Rui; Pan, Yubai

    2016-07-01

    In this paper, a diode-pumped continuous-wave and passively Q-switched 1.06 μm laser with gain medium of ceramic was demonstrated. Laser output characteristics using Nd:YAG ceramics with different doping concentrations of 1.0%, 2.0%, and 4.0% were studied. A maximum output power of 7.74 W with optical efficiency of 51.6% was obtained through the optimization of the coupler's transmission. By using Cr4+:YAG crystals with initial transmissions of 80% and 90% as saturable absorbers, the pulsed ceramic Nd:YAG laser performance was investigated.

  17. Compact, Passively Q-Switched Nd:YAG Laser for the MESSENGER Mission to the Planet Mercury

    NASA Technical Reports Server (NTRS)

    Krebs, Danny J.; Novo-Gradac, Anne-Marie; Li, Steven X.; Lindauer, Steven J.; Afzal, Robert S.; Yu, Antony

    2004-01-01

    A compact, passively Q-switched Nd:YAG laser has been developed for the Mercury Laser Altimeter (MLA) instrument which is an instrument on the MESSENGER mission to the planet Mercury. The laser achieves 5.4 percent efficiency with a near diffraction limited beam. It has passed all space flight environmental tests at system, instrument, and satellite integration. The laser design draws on a heritage of previous laser altimetry missions, specifically ISESAT and Mars Global Surveyor; but incorporates thermal management features unique to the requirements of an orbit of the planet Mercury.

  18. Theoretical and experimental investigation of the nonlinear dynamical trends of passively mode-locked quantum dot lasers

    NASA Astrophysics Data System (ADS)

    Raghunathan, Ravi

    In recent years, passively mode-locked quantum dot lasers have shown great promise as compact, efficient and reliable pulsed sources of light for a range of precision and high performance applications, such as high bit-rate optical communications, diverse waveform generation, metrology, and clock distribution in high-performance computing (HPC) processors. For such applications, stable optical pulses with short picosecond pulse durations and multi-gigahertz repetition rates are required. In addition, a low pulse-to-pulse timing jitter is also necessary to prevent errors arising from the ambiguity between neighboring pulses. In order to optimize pulse quality in terms of optical characteristics such as pulse shape and pulse train behavior, as well as RF characteristics such as phase noise and timing jitter, understanding the nonlinear output dynamics of such devices is of critical importance, not only to get a sense of the regimes of operation where device output might be stable or unstable, but also to gain insight into the parameters that influence the output characteristics the most, and how they can be accessed and exploited to optimize design and performance for next generation applications. In this dissertation, theoretical and experimental studies have been combined to investigate the dynamical trends of two-section passively mode-locked quantum dot lasers. On the theoretical side, a novel numerical modeling scheme is presented as a powerful and versatile framework to study the nonlinear dynamics specific to a device, with device-specific parameters extracted over a range of operating conditions. The practical utility of this scheme is then demonstrated, first, in an analytical capability to interpret and explain dynamical trends observed in experiment, and subsequently, as a predictive tool to guide experiment to operate in a desired dynamical regime. Modeling results are compared to experimental findings where possible. Finally, optical feedback from an

  19. Passive mode locking of a femtosecond Ti:sapphire laser with pulsed synchronous pumping by a finite train of picosecond pulses

    SciTech Connect

    Borisevich, N A; Buganov, O V; Tikhomirov, S A; Tolstorozhev, G B; Shkred, G L

    1999-09-30

    An analysis is made, with the aid of the self-consistent nonlinear ABCD matrix method, of the specific features of the mechanism of passive mode locking of a femtosecond Ti:sapphire laser under conditions of pulsed synchronous pumping. The conditions of stable laser operation are studied. It is proposed to use an additional aperture as an element of negative feedback for the stabilisation of passive mode locking. Practical recommendations concerning the optimisation of a femtosecond laser are given. (control of laser radiation parameters)

  20. Cr4 + :Gd3Sc2Ga3O12 passive Q-switch for the Cr3 + :LiCaAlF6 laser

    NASA Astrophysics Data System (ADS)

    Kuo, Yen-Kuang; Yang, Yang; Birnbaum, Milton

    1994-05-01

    A Cr4+:Gd3Sc2Ga3O12 (Cr4+:GSGG) broad-band saturable absorber has been demonstrated to be an excellent passive Q-switch for the flashlamp-pumped tunable Cr3+:LiCaAlF6 (Cr:LiCAF) laser at room temperature. A single Q-switched laser output pulse of 11 mJ in energy and 37 ns in duration at 778 nm was obtained in a nonoptimized laser.

  1. Passively mode-locked Tm,Ho:YAG laser at 2 microm based on saturable absorption of intersubband transitions in quantum wells.

    PubMed

    Yang, Kejian; Bromberger, Hubertus; Ruf, Hartmut; Schäfer, Hanjo; Neuhaus, Joerg; Dekorsy, Thomas; Grimm, Christiana Villas-Boas; Helm, Manfred; Biermann, Klaus; Künzel, Harald

    2010-03-29

    We report the first demonstration of a solid state laser passively mode-locked through the saturable absorption of short-wavelength intersubband transitions in doped quantum wells: a continuous wave Ti:sapphire laser end-pumped Tm,Ho:YAG laser at the center wavelength of 2.091 mum utilizing intersubband transitions in narrow In(0.53)Ga(0.47)As/Al(0.53)As(0.47)Sb quantum wells. Stable passive mode-locking operation with maximum average output power of up to 160 mW for 2.9 W of the absorbed pump power could last for hours without external interruption and a mode-locked pulse with duration of 60 ps at repetition rate of 106.5 MHz was generated. PMID:20389677

  2. Observation of multipulse bunches in a graphene oxide passively mode-locked ytterbium-doped fiber laser with all-normal dispersion

    NASA Astrophysics Data System (ADS)

    Huang, Shisheng; Wang, Yonggang; Peiguang, Yan; Zhang, Gelin; Zhao, Junqing; Li, Huiquan; Lin, Rongyong; Cao, Guangzhong; Duan, Ji'an

    2014-09-01

    We give a systematic experimental study of multipulse bunches in a graphene oxide saturable absorber (GOSA) passively mode-locked all-normal dispersion ytterbium-doped fiber laser (YDFL). Some special phenomena such as harmonic multipulse bunches, harmonic mode-locking, and chaotic multipulse states are also obtained. Our experiment reveals that the inserted 2.5-nm narrow bandwidth filter plays an important role in the formation of multipulse in all-normal dispersion fiber lasers. Because of the effective gain bandwidth depends on both the 2.5-nm narrow bandwidth filter and the artificial fiber birefringence filter, the multipulse operation states are sensitive to the polarization. It is the first demonstration of multipulse evolution in a GOSA passively mode-locked all-normal dispersion YDFL.

  3. Passive mode locking of a GaSb-based quantum well diode laser emitting at 2.1 μm

    SciTech Connect

    Merghem, K.; Aubin, G.; Ramdane, A.; Teissier, R.; Baranov, A. N.; Monakhov, A. M.

    2015-09-14

    We demonstrate passive mode locking of a GaSb-based diode laser emitting at 2.1 μm. The active region of the studied device consists in two 10-nm-thick GaInSbAs/GaAlSbAs quantum wells. Passive mode locking has been achieved in a two-section laser with one of the sections used as a saturable absorber. A microwave signal at 20.6 GHz, measured in the electrical circuit of the absorber, corresponds to the fundamental photon round-trip frequency in the laser resonator. The linewidth of this signal as low as ∼10 kHz has been observed at certain operating conditions, indicating low phase noise mode-locked operation.

  4. High-power passively mode-locked laser at 1062.4  nm based on Nd:LaGGG disordered crystal.

    PubMed

    Su, Xiancui; Zhao, Ruwei; Zhang, Baitao; Jia, Zhitai; Hou, Jia; He, Jingliang

    2015-03-10

    A diode-pumped passively continuous-wave mode-locked Nd:(La(x)Gd(1-x))3Ga5O12 (Nd:LaGGG) laser at 1062.4 nm with a semiconductor saturable absorber mirror was demonstrated for the first time, to the best of our knowledge. Pulses with duration of 12.78 ps were produced at a repetition rate of 59.8 MHz. A maximum average mode-locked output power of 3.18 W was obtained at the absorbed pumped power of 10.12 W, corresponding to a slope efficiency of 35.7% and a peak power of 4.2 kW. As far as we know, this is the highest power obtained in the passively mode-locking operation with Nd3+-doped disordered garnet crystals. PMID:25968392

  5. Sub-300 femtosecond soliton tunable fiber laser with all-anomalous dispersion passively mode locked by black phosphorus.

    PubMed

    Chen, Yu; Chen, Shuqing; Liu, Jun; Gao, Yanxia; Zhang, Wenjing

    2016-06-13

    By using evanescent field optical deposition method, we had successfully fabricated an effective optoelectronic device based on multi-layer black phosphorus (BP), which is been heavily investigating 2 dimensional (2D) semiconducting material with similar structure as graphene and thickness dependent direct band-gap. By placing this BP-based optoelectronic device inside a highly compact all-anomalous dispersion fiber laser cavity, stable passive mode-locking operation could be ensured and eventually a record 280 fs transmission limited soliton pulse with tunable central wavelength had been obtained through finely tailoring the cavity length. Other operation states, like bound soliton and noise-like state, had also been observed as well. This work demonstrates the enormous potential of BP for ultra-short pulse generation as an effective optoelectronic device. PMID:27410348

  6. Experimental investigations on spectrum width of square-wave pulses in passively mode-locked figure-8 fiber laser

    NASA Astrophysics Data System (ADS)

    Mei, Li; Xu, Lixin; Chen, Guoliang; Gu, Chun; Zhang, Xianming; Sun, Biao; Lin, Jian; Wang, Anting

    2014-10-01

    We have proposed and demonstrated a nanosecond square-wave fiber laser working in the 1060nm band. The passively mode-locked fiber laser based on the nonlinear optical loop mirror has a peak power clamping effect which leads to the generation of nanosecond square-wave pulses. To investigate the spectrum width of the nanosecond square-wave pulse laser, we added couplers with different coupling ratio to the bidirectional ring of the figure-8 fiber laser and analyzed the laser output. The results show that a higher output coupling ratio leads to stronger peak power clamping effect, and the peak power of the square-wave pulse gets lower and the corresponding spectrum band width is narrower.

  7. High-pulse-energy passively mode-locked Nd:YVO4 laser without spatial hole burning effect

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Chen, Meng; Li, Gang

    2014-05-01

    We report on a high-pulse-energy 888 nm diode-pumped passively mode-locked TEM00 Nd:YVO4 oscillator without spatial hole burning (SHB) effect in active medium. At a pump power of 40 W, the oscillator produced pulse energy up to 270 nJ at a repetition rate of 50 MHz, corresponding to average power of 13.5W with 34% optical-to-optical efficiency. To the best of our knowledge, it is the highest pulse energy obtained at the same pump power. The pulse duration produced varied from 16 to 59 ps. By varying the pump power, we observed a pulse duration ranging from 52 to 59 ps while the time-bandwidth product remained 0.88, and the factors that affect the pulse duration were also discussed. Meanwhile, a novel method of adjusting output coupling (OC) was introduced, which can simplify the structure of laser.

  8. 2 GHz passively harmonic mode-locked fiber laser by a microfiber-based topological insulator saturable absorber.

    PubMed

    Luo, Zhi-Chao; Liu, Meng; Liu, Hao; Zheng, Xu-Wu; Luo, Ai-Ping; Zhao, Chu-Jun; Zhang, Han; Wen, Shuang-Chun; Xu, Wen-Cheng

    2013-12-15

    We report on the generation of passive harmonic mode locking of a fiber laser using a microfiber-based topological insulator (TI) Bi(2)Te(3) saturable absorber (SA). The optical deposition method was employed to fabricate the microfiber-based TISA. By virtue of the excellent nonlinear optical property of the proposed TISA, the fiber laser could operate at the pulse repetition rate of 2.04 GHz under a pump power of 126 mW, corresponding to the 418th harmonic of fundamental repetition frequency. The results demonstrate that the microfiber-based TI photonic device can operate as both the high nonlinear optical component and the SA in fiber lasers, and could also find other applications in the related fields of photonics. PMID:24322220

  9. A passively mode-locked intracavity frequency doubled Nd:YVO4 femtosecond green laser based on graphene

    NASA Astrophysics Data System (ADS)

    Shi, R. P.; Bai, Y.; Qi, M.; Chen, X. M.; Wei, H. D.; Ren, Z. Y.; Bai, J. T.

    2014-02-01

    By using an atmospheric-pressure chemical vapor deposition (APCVD) method with a C2H2 carbon source, seven-layer graphene films as saturable absorbers are fabricated and transferred to an anti-reflective mirror of 1064 nm wavelength range. Based on this transmission-type graphene saturable absorber mirror (GSAM), a continuous wave (CW) passively mode-locked femtosecond green laser is achieved by 808 nm laser diode (LD) end-pumped Nd:YVO4 crystal and type-I critical phase-matched LBO crystal intracavity frequency doubling for the first time. Stable ultrashort green laser pulses as short as 374 fs are measured with a repetition rate of 71.4 MHz and an average output power of 117 mW at a central wavelength of 531.7 nm.

  10. LD-end-pumped passively Q-switched Nd:YAG ceramic laser with single wall carbon nanotube saturable absorber

    NASA Astrophysics Data System (ADS)

    Li, C. Y.; Bo, Y.; Zong, N.; Wang, Y. G.; Jiang, B. X.; Pan, Y. B.; Niu, G.; Fan, Z. W.; Peng, Q. J.; Cui, D. F.; Xu, Z. Y.

    2012-10-01

    We report on a LD-end-pumped passively Q-switched Nd:YAG ceramic laser by using a novel single wall carbon nanotube saturable absorber (SWCNT-SA). The SWCNT wafer was fabricated by electric Arc discharge method on quartz substrate with absorption wavelength of 1064 nm. We firstly investigated the continuous wave (CW) laser performance and scattering properties of Nd:YAG ceramic sample. For the case of passively Q-switched operation, a maximum output power of 376 mW was obtained at an incident pump power of 8.68 W at 808 nm, corresponding to an optical-optical conversion efficiency of 4.3%. The repetition rate as the increase of pump power varied from 14 to 95 kHz. The minimum pulse duration of 1.2 μs and maximum pulse energy of 4.5 μJ was generated at a repetition rate of 31.8 kHz.

  11. Ultrafast in-situ probing of passively mode-locked VECSEL dynamics

    NASA Astrophysics Data System (ADS)

    Scheller, Maik; Baker, Caleb W.; Gbele, Kokou; Koch, Stephan W.; Jones, R. Jason; Moloney, Jerome V.

    2015-03-01

    While Vertical-External-Cavity-Surface-Emitting-Lasers (VECSELs) have been successfully used as ultrafast laser sources with pulse durations in the hundreds of femtosecond regime, the dynamics within the semiconductor gain structure are not yet completely understood. With the high carrier densities inside the semiconductor, nonequilibrium effects such as kinetic-hole burning are expected to play a major role in pulse formation dynamics. Moreover, the nonlinear phase change by the intense light field can induce a complex dispersion, which may potentially limit the achievable pulse durations. To shed light on such nonequilibrium dynamics, we perform in-situ characterization of mode-locked VECSELs. We probe the gain media as well as the intracavity absorber with a femtosecond fiber laser source. For measuring temporal characteristics, we employ an asynchronous optical sampling technique by phase-locking the repetition rate of the VECSEL to a multiple of the probe laser with an adjustable offset frequency. This allows for probing dynamics from femtosecond to nanosecond time scales with scan rates up to hundreds of Hertz without compromise of measurement precision which can be introduced by mechanical delays covering such large temporal windows. With a resolution in the femtosecond range, we characterize gain depletion by the intracavity pulse as well as the gain recovery timescales for different power levels and operation regimes.

  12. Experimental study on the multisoliton pattern formation in an erbium-doped fiber laser passively mode-locked by graphene saturable absorber

    NASA Astrophysics Data System (ADS)

    Feng, Qi; Chen, Yu; Zhao, Chujun; Li, Ying; Wen, Jianguo; Zhang, Han

    2013-04-01

    We demonstrate an erbium-doped fiber laser passively mode-locked by few layers of graphene prepared by the mechanical exfoliation of the high oriented pyrolytic graphite through the Scotch-tape method. This all-fiber ring cavity delivered a pulse train with a repetition rate of 1.646 MHz and pulse duration of 1.656 ps. By continuously adjusting the laser cavity parameters, one can observe various soliton patterns, such as ordered-, chaotic-, bunched-, and harmonic-multisoliton state. This evidenced that a mode-locked fiber laser based on graphene saturable absorber indeed provided a well-controlled nonlinear optics platform for soliton dynamics study.

  13. High efficiency passively mode-locked Nd:YVO4 laser with direct in-band pumping at 914 nm.

    PubMed

    Waritanant, Tanant; Major, Arkady

    2016-06-13

    We report on the performance of a semiconductor saturable absorber mirror passively mode-locked Nd:YVO4 laser with in-band pumping at 914 nm and with the highest slope efficiency to date among the mode-locked Nd-lasers. The laser produced 6.7 W of output power with repetition rate of 87 MHz and pulse duration of 16 ps. The slope efficiency of 77.1% and the optical-to-optical efficiency of 60.7% were achieved. PMID:27410304

  14. CONTROL OF LASER RADIATION PARAMETERS. GENERATION OF ULTRASHORT PULSES: Passive mode locking in a cw dye laser with a rapidly relaxing absorber

    NASA Astrophysics Data System (ADS)

    Krindach, D. P.; Kur'yanov, A. A.; Novoderezhkin, V. I.

    1990-12-01

    Theoretical and experimental investigations were made of the characteristics of passive mode locking in a cw dye laser with a rapidly relaxing absorber. It was found that such a "fast" absorber was prone to fluctuations. This altered the limits and widened the mode-locking range in the direction of higher energy densities of the pulses, compared with a "slow" absorber of the DODCI type. This made it possible to generate pulses shorter than 100 fs with an average power of 30-50 mW.

  15. High energy pulses generation with giant spectrum bandwidth and submegahertz repetition rate from a passively mode-locked Yb-doped fiber laser in all normal dispersion cavity

    NASA Astrophysics Data System (ADS)

    Lin, J.-H.; Wang, D.; Lin, K.-H.

    2011-01-01

    Robust passively mode-locked pulse generation with low pulse repetition rate and giant spectrum bandwidth in an all-fiber, all-normal-dispersion ytterbium-doped fiber laser has been experimentally demonstrated using nonlinear polarization evolution technique. The highest pulse energy over 20 nJ with spectrum bandwidth over 50 nm can be experimentally obtained at 175 mW pump power. The mode-locked pulses reveal broadened 3-dB pulsewidth about several nanosecond and widened pedestal in time trace that is resulted from enormous dispersion in laser cavity and gain dynamics. At certain mode-locking state, a spectrum gap around 1056 nm are observed between the three and four energy levels of Yb-doped fiber laser. By properly rotating the polarization controller, the gap can be eliminated due to four-wave mixing to produce more flattened spectrum output.

  16. High-order harmonic noise-like pulsing of a passively mode-locked double-clad Er/Yb fibre ring laser

    NASA Astrophysics Data System (ADS)

    Pottiez, O.; Hernández-García, J. C.; Ibarra-Escamilla, B.; Kuzin, E. A.; Durán-Sánchez, M.; González-García, A.

    2014-11-01

    In this paper, we study noise-like pulse generation in a km-long fibre ring laser including a double-clad erbium-ytterbium fibre and passively mode-locked through nonlinear polarization evolution. Although single noise-like pulsing is only observed at moderate pump power, pulse energies as high as 120 nJ are reached in this regime. For higher pump power, the pulse splits into several noise-like pulses, which then rearrange into a stable and periodic pulse train. Harmonic mode locking from the 2nd to the 48th orders is readily obtained. At pump powers close to the damage threshold of the setup, much denser noise-like pulse trains are demonstrated, reaching harmonic orders beyond 1200 and repetition frequencies in excess of a quarter of a GHz. The mechanisms leading to noise-like pulse breaking and stable high-order harmonic mode locking are discussed.

  17. Watt-level passively mode-locked Er(3+)-doped ZBLAN fiber laser at 2.8  μm.

    PubMed

    Tang, Pinghua; Qin, Zhipeng; Liu, Jun; Zhao, Chujun; Xie, Guoqiang; Wen, Shuangchun; Qian, Liejia

    2015-11-01

    We experimentally demonstrated a stable, high-average-power, continuous-wave (CW) passively mode-locked Er(3+)-doped ZBLAN fiber laser at 2.8 μm based on a semiconductor saturable absorber mirror. A stable mode-locked laser with a signal-to-noise ratio of 52 dB and a slope efficiency of 14% was obtained. The highest average output power in excess of 1 W was generated at the incident pump power of 8.2 W, with a pulse repetition rate of 22.56 MHz and pulse duration of 25 ps. To the best of our knowledge, this is the highest average output power of a CW mode-locked ZBLAN fiber laser in the mid-infrared wavelength regime up to now. PMID:26512467

  18. Single-walled carbon nanotube saturable absorber for a diode-pumped passively mode-locked Nd,Y:SrF2 laser

    NASA Astrophysics Data System (ADS)

    Li, Chun; Cai, Wei; Liu, Jie; Su, Liangbi; Jiang, Dapeng; Ma, Fengkai; Zhang, Qian; Xu, Jun; Wang, Yonggang

    2016-08-01

    A reflective single-walled carbon nanotube as saturable absorber has been firstly adopted to a passively mode-locked Nd,Y:SrF2 crystal. Without any dispersion compensation, the stably mode-locked laser delivers pulses with pulse width as short as 1.7 ps, repetition rate of 107.8 MHz and center wavelength of 1056 nm. The oscillator produces maximum average output power of 319 mW corresponding with a high slope efficiency of 20.2%. The single pulse energy and the peak power are 2.96 nJ and 1.74 kW, respectively. The experimental results show that single-walled carbon nanotube is an excellent saturable absorber for mode-locked lasers.

  19. Passive mode-locking characteristics from the Nd:Gd0.19Y0.81VO4 laser at 1.34 μm

    NASA Astrophysics Data System (ADS)

    Qiao, Wenchao; Chu, Hongwei; Zhao, Shengzhi; Li, Guiqiu; Yang, Kejian; Li, Tao; Zhao, Jia

    2016-08-01

    We report a passively continuous-wave mode-locked (CWML) Nd:Gd0.19Y0.81VO4 laser oscillating at 1342.3 nm for the first time in this paper. Stable mode-locked pulse cluster with a pulse width of 7.2 ps and a pulse repetition frequency of 32.8 MHz has been realized with a semiconductor saturable absorber mirror (SESAM). The highest output power was 880 mW when the incident pump power was 7.1 W, corresponding to an optical conversion efficiency of 12.4%. The mode-locked pulse energy was about 26.83 nJ, while the peak power was 3.73 kW.

  20. High-pulse-energy passively Q-switched quasi-monolithic microchip lasers operating in the sub-100-ps pulse regime.

    PubMed

    Nodop, D; Limpert, J; Hohmuth, R; Richter, W; Guina, M; Tünnermann, A

    2007-08-01

    We present passively Q-switched microchip lasers with items bonded by spin-on-glass glue. Passive Q-switching is obtained by a semiconductor saturable absorber mirror. The laser medium is a Nd:YVO(4) crystal. These lasers generate pulse peak powers up to 20 kW at a pulse duration as short as 50 ps and pulse repetition rates of 166 kHz. At 1064 nm, a linear polarized transversal and longitudinal single-mode beam is emitted. To the best of our knowledge, these are the shortest pulses in the 1 microJ energy range ever obtained with passively Q-switched microchip lasers. The quasi-monolithic setup ensures stable and reliable performance. PMID:17671554

  1. Third-order nonlinearity and passive Q-switching of Cr⁴⁺:YGG garnet crystal.

    PubMed

    Wang, Shuxian; Zhang, Yuxia; Wu, Kui; Zhang, Rui; Yu, Haohai; Zhang, Huaijin; Zhang, Guanghui; Xiong, Qihua

    2015-05-15

    We demonstrate the third-order nonlinear optical properties of Cr(4+):Y(3)Ga(5)O(12) (Cr(4+):YGG) and Q-switched lasers with Cr(4+):YGG as the saturable absorber for the first time to our knowledge. The third-order nonlinear properties, including the optical Kerr nonlinearity and saturable absorption, were systematically measured and analyzed in detail by using a Z-scan technique. The measured data show that Cr(4+):YGG has a large nonlinear refractive index, ground-state absorption cross section, and excited-state absorption cross section in contrast to Cr(4+):Y(3)Al(5)O(12) (Cr(4+):YAG). With a Nd:YGG crystal as the gain medium and a Cr(4+):YGG crystal as the saturable absorber, the passively Q-switched laser was performed. The shortest pulse width and largest pulse energy were achieved at the absorbed pump power of 8 W with the values of 9.1 ns and 26.1 μJ, respectively, corresponding to the average output power of 0.87 W and peak power of 2.9 kW. The results indicate that Cr(4+):YGG is an available and promising optical switcher for pulsed lasers. PMID:26393755

  2. Yb:YAG thin disk laser passively Q-switched by a hydro-thermal grown molybdenum disulfide saturable absorber

    NASA Astrophysics Data System (ADS)

    Zhan, Yi; Wang, Li; Wang, Jie Yu; Li, Hong Wei; Yu, Zhen Huang

    2015-02-01

    We demonstrate a passively Q-switched Yb:YAG thin disk solid-state laser based on nanoflake MoS2 as a saturable absorber. MoS2 is synthesized by a hydro-thermal process. The prepared MoS2 is transferred onto the BK7 glass for ease-of-use in the solid-state laser as a saturable absorber. The average output power could reach up to 250 mW, center wavelength 1030 nm corresponding to a pulse width, a pulse repetition rate, and a per pulse energy of 12 μs, 17 kHz, and 15 μJ, respectively. Our results show that nanoflake MoS2 could be a promising saturable absorber for Q-switching solid-state lasers. The over saturation of the MoS2 saturable absorber at a high pump strength limit in a solid-state laser could be also effective for high power operation.

  3. Passively Q-switched dual-wavelength Yb:LSO laser based on tungsten disulphide saturable absorber

    NASA Astrophysics Data System (ADS)

    Jing-Hui, Liu; Jin-Rong, Tian; He-Yang, Guoyu; Run-Qin, Xu; Ke-Xuan, Li; Yan-Rong, Song; Xin-Ping, Zhang; Liang-Bi, Su; Jun, Xu

    2016-03-01

    We demonstrate a passively Q-switched Yb:LSO laser based on tungsten disulphide (WS2) saturable absorber operating at 1034 nm and 1056 nm simultaneously. The saturable absorbers were fabricated by spin coating method. With low speed, the WS2 nanoplatelets embedded in polyvinyl alcohol could be coated on a BK7 glass substrate coated with high-refractive-index thin polymer. The shortest pulse width of 1.6 μs with a repetition rate of 76.9 kHz is obtained. As the pump power increases to 9 W, the maximum output power is measured to be 250 mW, corresponding to a single pulse energy of 3.25 μJ. To the best of our knowledge, this is the first time to obtain dual-wavelength Q-switched solid-state laser using few-layer WS2 nanoplatelets. Project supported by the National Scientific Research Project of China (Grant No. 61177047), Beijing Municipal Natural Science Foundation, China (Grant No. 1102005), and the Basic Research Foundation of Beijing University of Technology, China (Grant No. X3006111201501).

  4. LD-pumped passively Q-switched Nd:GGG laser at 1062 nm with a GaAs saturable absorber

    NASA Astrophysics Data System (ADS)

    Zhang, H. N.; Li, P.; Wang, Q. P.; Chen, X. H.

    2011-11-01

    we have experimentally studied the passively Q-switched performance of a diode-pumped Nd:GGG laser at 1062 nm with a GaAs saturable absorber, in the experiment when the pumped power was 9.8 W, the maximum CW output power of 5.1 W was obtained. The optical conversion efficiency and the slop efficiency were 52 and 53%, respectively. The threshold was 0.9 W. In the passively Q-switched regime, we get the average output power of 0.93 W. The shortest pulse width and pulse repetition rate were 7 ns and 188 kHz, respectively.

  5. MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Wei, Rongfei; Zhang, Hang; Tian, Xiangling; Qiao, Tian; Hu, Zhongliang; Chen, Zhi; He, Xin; Yu, Yongze; Qiu, Jianrong

    2016-03-01

    Strong saturable absorption was observed in MoS2 nanoflowers, which were synthesized by a facile solvothermal method. A MoS2 nanoflower-based saturable absorber with a high modulation depth of 51.8% and a large saturable intensity of 275.5 GW cm-2 was introduced to the application of passively Q-switched fiber laser generation. Stable passively Q-switched fiber laser pulses at 1.56 μm with a low threshold power of 16.10 mW, high signal-to-noise ratio of 52.5 dB and short pulse duration of 1.9 μs were obtained. More importantly, a high output power of 3.10 mW related to a large pulse energy of about 51.84 nJ can be attained at a very low pump power. The efficiency of the laser reaches 4.71%, which is larger than that of the prepared layered MoS2 and recently reported MoS2-based passively Q-switching operations. Such results imply that the MoS2 nanoflowers are an excellent candidate for a saturable absorber in passively Q-switched fiber lasers at a low pump intensity.Strong saturable absorption was observed in MoS2 nanoflowers, which were synthesized by a facile solvothermal method. A MoS2 nanoflower-based saturable absorber with a high modulation depth of 51.8% and a large saturable intensity of 275.5 GW cm-2 was introduced to the application of passively Q-switched fiber laser generation. Stable passively Q-switched fiber laser pulses at 1.56 μm with a low threshold power of 16.10 mW, high signal-to-noise ratio of 52.5 dB and short pulse duration of 1.9 μs were obtained. More importantly, a high output power of 3.10 mW related to a large pulse energy of about 51.84 nJ can be attained at a very low pump power. The efficiency of the laser reaches 4.71%, which is larger than that of the prepared layered MoS2 and recently reported MoS2-based passively Q-switching operations. Such results imply that the MoS2 nanoflowers are an excellent candidate for a saturable absorber in passively Q-switched fiber lasers at a low pump intensity. Electronic supplementary

  6. Passively Q-switched 1617-nm polycrystalline ceramic Er:YAG laser using a Cr:ZnSe saturable absorber

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoqi; Shen, Deyuan; Huang, Haitao; Liu, Jun; Zhang, Jian; Tang, Dingyuan; Fan, Dianyuan

    2015-08-01

    We report on a passively Q-switched polycrystalline ceramic Er:YAG laser by using a Cr:ZnSe crystal as a saturable absorber. When pumped by a 1532-nm Er-, Yb-doped fiber laser with the maximum power of 12.4 W, the laser yielded pulses of 28.8 ns duration at 1617 nm by using a saturable absorber with an initial transmission of 80 %. The corresponding peak power was up to 11.3 kW at a repetition rate of 2.17 kHz. The dependence of the pulse duration and repetition rate on the pump power was experimentally studied. The numerical and experimental results both show that the pulse duration was mainly determined by the initial transmission of the saturable absorber and slightly affected by the transmission of the output coupler. At last, we give some prospects for further narrowing down the pulse duration.

  7. Analytical solution of the transient temperature profile in gain medium of passively Q-switched microchip laser.

    PubMed

    Han, Xiahui; Li, Jianlang

    2014-11-01

    The transient temperature evolution in the gain medium of a continuous wave (CW) end-pumped passively Q-switched microchip (PQSM) laser is analyzed. By approximating the time-dependent population inversion density as a sawtooth function of time and treating the time-dependent pump absorption of a CW end-pumped PQSM laser as the superposition of an infinite series of short pumping pulses, the analytical expressions of transient temperature evolution and distribution in the gain medium for four- and three-level laser systems, respectively, are given. These analytical solutions are applied to evaluate the transient temperature evolution and distribution in the gain medium of CW end-pumped PQSM Nd:YAG and Yb:YAG lasers. PMID:25402922

  8. CW and passively Q-switched laser performance of Nd:Lu2SiO5 crystal

    NASA Astrophysics Data System (ADS)

    Xu, Xiaodong; Di, Juqing; Zhang, Jian; Tang, Dingyuan; Xu, Jun

    2016-01-01

    We demonstrated an efficient and controllable dual-wavelength continuous-wave (CW) laser of Nd:Lu2SiO5 (Nd:LSO) crystal. The maximum output power was 3.02 W at wavelength of 1075 nm and 1079 nm, and with increasing of absorbed pump power, the ratio of 1079 nm laser rose. The slope efficiency of 65.6% and optical-to-optical conversion efficiency of 63.3% were obtained. The passively Q-switched laser properties of Nd:LSO were investigated for the first time. The shortest pulse, maximum pulse energy and peak power were 11.58 ns, 29.05 μJ and 2.34 kW, respectively.

  9. Passively Q-switched 2 μm Tm:YAP laser based on graphene saturable absorber mirror.

    PubMed

    Hou, Jia; Zhang, Baitao; He, Jingliang; Wang, Zhaowei; Lou, Fei; Ning, Jian; Zhao, Ruwei; Su, Xiancui

    2014-08-01

    Using high-quality single-layer graphene as a saturable absorber, Tm:YAlO₃ (Tm:YAP) crystal as the gain medium, we demonstrated a laser-diode-pumped, compact, passively Q-switched (PQS) solid-state laser in the 2 μm region. The maximum average output power was 362 mW, with the corresponding largest pulse repetition rate and pulse energy of 42.4 kHz and 8.5 μJ, respectively. Under the same pump power, the pulse width of 735 ns was obtained, which is, to our best knowledge, the shortest pulse width among Tm-doped solid-state PQS lasers using graphene saturable absorber mirrors. PMID:25090328

  10. Narrow-band 1 W source at 257 nm using frequency quadrupled passively Q-switched Yb:YAG laser.

    PubMed

    Goldberg, Lew; Cole, Brian; McIntosh, Chris; King, Vernon; Hays, A D; Chinn, Stephen R

    2016-07-25

    We describe generation of 1.1 W of 257 nm emission by frequency quadrupling the 1030 nm emission from a compact passively Q-switched Yb:YAG laser. The laser utilized a volume Bragg grating to achieve a 0.1 nm linewidth required for UV-Raman spectroscopic applications, generated 100 kW peak power, 250 μJ pulses and 3.6 W of average power at 1030 nm. Fourth harmonic generation (FHG) was carried out using a 10 mm lithium triborate (LBO) crystal to generate 515 nm second harmonic with 70% conversion efficiency, followed by a 7 mm beta-barium borate (BBO) crystal to generate 257 nm fourth harmonic with 45% efficiency, resulting in an overall nonlinear conversion efficiency of 31%. Far-field and near-field of the FHG emission were characterized. PMID:27464186

  11. High-power passively mode-locked Nd:YVO(4) laser using SWCNT saturable absorber fabricated by dip coating method.

    PubMed

    Tang, Chun Yin; Chai, Yang; Long, Hui; Tao, Lili; Zeng, Long Hui; Tsang, Yuen Hong; Zhang, Ling; Lin, Xuechun

    2015-02-23

    Passive mode locked laser is typically achieved by the Semiconductor Saturable absorber Mirror, SESAM, saturable absorber, which is produced by expensive and complicated metal organic chemical vapor deposition method. Carbon based single wall carbon nanotube (SWCNT), saturable absorber, is a promising material which is capable to produce stable passive mode-locking in the high power laser cavity over a wide operational wavelength range. This study has successfully demonstrated the high power mode locking laser system operating at 1 micron by using SWCNT based absorbers fabricated by dip coating method. The proposed fabrication method is practical, simple and cost effective for fabricating SWCNT saturable absorber. The demonstrated high power Nd:YVO(4) mode-locked laser operating at 1064nm have maximum output power up to 2.7W,with the 167MHz repetition rate and 3.1 ps pulse duration, respectively. The calculated output pulse energy and peak power are 16.1nJ and 5.2kW, respectively. PMID:25836523

  12. High-damage-resistant tungsten disulfide saturable absorber mirror for passively Q-switched fiber laser.

    PubMed

    Chen, Hao; Chen, YuShan; Yin, Jinde; Zhang, Xuejun; Guo, Tuan; Yan, Peiguang

    2016-07-25

    In this paper, we demonstrate a high-damage-resistant tungsten disulfide saturable absorber mirror (WS2-SAM) fabricated by magnetron sputtering technique. The WS2-SAM has an all-fiber-integrated configuration and high-damage-resistant merit because the WS2 layer is protected by gold film so as to avoid being oxidized and destroyed at high pump power. Employing the WS2-SAM in an Erbium-doped fiber laser (EDFL) with linear cavity, the stable Q-switching operation is achieved at central wavelength of 1560 nm, with the repetition rates ranging from 29.5 kHz to 367.8 kHz and the pulse duration ranging from 1.269 μs to 154.9 ns. For the condition of the maximum pump power of 600 mW, the WS2-SAM still works stably with an output power of 25.2 mW, pulse energy of 68.5 nJ, and signal-noise-ratio of 42 dB. The proposed WS2-SAM configuration provides a promising solution for advanced pulsed fiber lasers with the characteristics of high damage resistance, high output energy, and wide tunable frequency. PMID:27464082

  13. Efficient passive Q-switching operation of a diode-pumped Nd:GdVO4 laser with a Cr4+:YAG saturable absorber

    NASA Astrophysics Data System (ADS)

    Liu, Junhai; Ozygus, Bernd; Yang, Suhui; Erhard, Jürgen; Seelig, Ute; Ding, Adalbert; Weber, Horst; Meng, Xianlin; Zhu, Li; Qin, Lianjie; Du, Chenlin; Xu, Xinguang; Shao, Zongshu

    2003-04-01

    A diode-pumped highly efficient Cr4+:YAG passively Q-switched Nd:GdVO4 laser formed by a plano-concave resonator has been demonstrated. At the highest attainable absorbed pump power of 11.4 W, 4.05 W of average output power, which was two thirds of the maximum corresponding cw output, was achieved with an optical conversion efficiency of 35.5%, and the slope efficiency was determined to be 46.8%, reaching 85% of the magnitude of its cw counterpart. The resulting shortest pulse duration, single-pulse energy, and peak power were found to be 13 ns, 90 μJ, and 7 kW, respectively, with a pulse repetition frequency (PRF) of 45 kHz. Two particularly modified resonator configurations were employed; the largest pulse energy and the highest peak power reached were, respectively, 154 μJ and 11.2 kW at 8.5 W of absorbed pump power. An analytical relation between the PRF and the absorbed pump power is given for a passively Q-switched laser, showing good consistency with experiment with a Nd:GdVO4 laser. The dependence of the operational parameters on the pump power and on the output coupling was also investigated experimentally. Issues involving the criterion for passive Q switching are discussed in some detail for Cr4+:YAG passively Q-switched neodymium-doped vanadate lasers.

  14. MoS2 nanoflowers as high performance saturable absorbers for an all-fiber passively Q-switched erbium-doped fiber laser.

    PubMed

    Wei, Rongfei; Zhang, Hang; Tian, Xiangling; Qiao, Tian; Hu, Zhongliang; Chen, Zhi; He, Xin; Yu, Yongze; Qiu, Jianrong

    2016-04-14

    Strong saturable absorption was observed in MoS2 nanoflowers, which were synthesized by a facile solvothermal method. A MoS2 nanoflower-based saturable absorber with a high modulation depth of 51.8% and a large saturable intensity of 275.5 GW cm(-2) was introduced to the application of passively Q-switched fiber laser generation. Stable passively Q-switched fiber laser pulses at 1.56 μm with a low threshold power of 16.10 mW, high signal-to-noise ratio of 52.5 dB and short pulse duration of 1.9 μs were obtained. More importantly, a high output power of 3.10 mW related to a large pulse energy of about 51.84 nJ can be attained at a very low pump power. The efficiency of the laser reaches 4.71%, which is larger than that of the prepared layered MoS2 and recently reported MoS2-based passively Q-switching operations. Such results imply that the MoS2 nanoflowers are an excellent candidate for a saturable absorber in passively Q-switched fiber lasers at a low pump intensity. PMID:26997036

  15. Gold nanobipyramids as saturable absorbers for passively Q-switched laser generation in the 1.1  μm region.

    PubMed

    Zhang, Huanian; Liu, Jie

    2016-03-15

    We demonstrated that gold nanobipyramids (Au-NBPs) can be used as saturable absorbers for ultrafast pulsed-laser application, for the first time. Au-NBPs are prepared through a seed-mediated growth method, and performance is investigated in a passively Q-switched Nd:YVO4 laser. In the Q-switched operation the maximum average output power that can be achieved is 151 mW. The minimum pulse width is 396 ns at a pulse repetition rate of 90.6 kHz. PMID:26977656

  16. Passive q-switching of CO/sub 2/ TEA laser using sulfur hexafluoride (SF/sub 6/). Report for April-August 1986

    SciTech Connect

    Pastel, R.

    1986-10-01

    Passive Q-switching of a CO/sub 2/ TEA laser using sulfur hexafluoride (SF/sub 6/) was demonstrated at 10.2 micron. There is minimum loss of peak power, narrowing of the pulse, and elimination of the tail. Q-switching at 9.6 micron was not observed. Also discussed is the use of SF/sub 6/ to frequency the laser to the strong gain lines of the 10.2-m and 9.6-m branch of the CO/sub 2/ emission. Both theory and experimental results are given.

  17. Diode-pumped CW and passively Q-switched lasers of Nd:GdLuAG mixed garnet at 1123 nm

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Liu, Zhaojun; Zhang, Sasa; Xia, Jinbao; Zhang, Yanmin; Guan, Chen

    2016-03-01

    Diode-pumped CW and passively Q-switched lasers of Nd:GdLuAG mixed garnet at 1123 nm were demonstrated. The maximum average output power of CW operation was 4.13 W. For Q-switched operation, the average output power was 800 mW, the corresponding single pulse energy was 133.8 μJ. The Nd:GdLuAG laser emitting at 1123 nm was obtained for the first time to the best of our knowledge, which proves that the Nd:GdLuAG mixed garnet has a better ability of energy storage than Nd:YAG in 1123 nm oscillation.

  18. Nanosecond pulse generation in a passively Q-switched Nd:GGG laser at 1331 nm by CVD graphene saturable absorber

    NASA Astrophysics Data System (ADS)

    Xu, Bin; Wang, Yi; Cheng, Yongjie; Yang, Han; Xu, Huiying; Cai, Zhiping

    2015-10-01

    We report on a nanosecond pulse generation in a diode end-pumped passively Q-switched Nd:GGG laser at the low-gain transition line of 1331 nm. A three-layer CVD graphene thin film was transferred from Cu foil to a BK7 glass substrate for the use of saturable absorber. A stable Q-switching laser operation was obtained with maximum average output power of 0.69 W and slope efficiency of about 11.0% with respect to the absorbed pump power. The shortest pulse duration and the maximum repetition rate of the pulse trains were registered to be 556 ns and 166.7 kHz with corresponding maximum pulse energy 4.14 μJ and pulse peak power 7.45 W. This is the first demonstration of CVD-graphene-based Q-switched laser operation at 1.3 μm, to the best of our knowledge.

  19. Passively mode-locking erbium-doped fiber lasers with 0.3 nm Single-Walled Carbon Nanotubes

    PubMed Central

    Xu, Xintong; Zhai, Jianpang; Li, Ling; Chen, Yanping; Yu, Yongqin; Zhang, Min; Ruan, Shuangchen; Tang, Zikang

    2014-01-01

    We demonstrate a passively mode-locked erbium-doped fiber laser (EDFL) by using the smallest single-walled carbon nanotubes (SWNTs) with a diameter of 0.3 nm as the saturable absorber. These ultrasmall SWNTs are fabricated in the elliptical nanochannels of a ZnAPO4-11 (AEL) single crystal. By placing an AEL crystal into an EDFL cavity pumped by a 980 nm laser diode, stable passive mode-locking is achieved for a threshold pump power of 280 mW, and 73 ps pulses at 1563.2 nm with a repetition rate of 26.79 MHz. PMID:25342292

  20. Generation of more than 40  W of average output power from a passively Q-switched Yb-doped fiber laser.

    PubMed

    Chakravarty, Usha; Kuruvilla, Antony; Singh, Ravindra; Upadhyaya, B N; Bindra, K S; Oak, S M

    2016-01-10

    We report on the generation of 41.6 W of average output power from a passively Q-switched ytterbium-doped fiber laser using Cr4+:YAG crystal as a saturable absorber (SA). This is the highest average power from passively Q-switched fiber lasers reported so far in the literature, to our knowledge, and it has been achieved by using a specially designed T-type double-end pumping configuration. Variation in average output power, pulse energy, pulse duration, pulse frequency, and pulse-to-pulse stability has also been studied using SAs of different linear transmissions. The effect of an intracavity SA on self-pulsing dynamics was also investigated and it was observed that, at lower input pump power near threshold, the presence of an SA enhances the peak power of relaxation oscillations to trigger the generation of stimulated Raman scattering in the gain fiber. With an increase in pump power, when the passive Q-switching threshold is reached, high peak power random self-pulses regenerate into low amplitude regular Q-switched pulses. The effect of the length of the gain medium on dual-wavelength generation at very low input pump power and broadband generation at sufficiently higher pump power has also been explored. PMID:26835764

  1. Determination of topological parameters of a laser with passive mode-locking on the basis of InGaAlAs/InGaAs/InP heterostructures

    NASA Astrophysics Data System (ADS)

    Mikhailovskii, G. A.; Polukhin, I. S.; Rybalko, D. A.; Solov'ev, Yu. V.; Odnoblyudov, M. A.

    2016-05-01

    Topological parameters of a strip-geometry laser with passive mode-locking on the basis of an InGaAlAs/InGaAs/InP heterostructure are determined from the condition for the existence of one transverse mode in a strip waveguide. The strip width was 1.5 μm, the mesa etch depth was 1.32 μm, and the thickness of the dielectric layer was 0.36 μm.

  2. Single- and double-walled carbon nanotube based saturable absorbers for passive mode-locking of an erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Cheng, Kuang-Nan; Lin, Yung-Hsiang; Lin, Gong-Ru

    2013-04-01

    The passive mode-locking of an erbium-doped fiber laser (EDFL) with a medium gain is demonstrated and compared by using three different types of carbon nanotubes (CNTs) doped in polyvinyl alcohol (PVA) films. Nano-scale clay is used to disperse the CNTs doped in the PVA polymer aqueous solution to serve as a fast saturable absorber to initiate passive mode-locking. The three types of CNT based saturable absorbers, namely single-walled (SW), double-walled (DW) and multi-walled (MW), are characterized by Raman scattering and optical absorption spectroscopy. The SW-CNTs with a diameter of 1.26 nm have two absorption peaks located around 1550 ± 70 and 860 ± 50 nm. In contrast, the DW-CNTs with a diameter of 1.33 nm reveal two absorption peaks located at 1580 ± 40 and 920 ± 50 nm. By using the SW-CNT based saturable absorber, the passively mode-locked EDFL exhibits a pulsewidth of 1.28 ps and a spectral linewidth of 1.99 nm. Due to the increased linear absorption of the DW-CNT based saturable absorber, the intra-cavity net gain of the EDFL is significantly attenuated to deliver an incompletely mode-locked pulsewidth of 6.8 ps and a spectral linewidth of 0.62 nm. No distinct pulse-train is produced by using the MW-CNT film as the saturable absorber, which is attributed to the significant insertion loss of the EDFL induced by the large linear absorption of the MW-CNT film.

  3. Thulium/holmium-doped fiber laser passively mode locked by black phosphorus nanoplatelets-based saturable absorber.

    PubMed

    Yu, Hao; Zheng, Xin; Yin, Ke; Cheng, Xiang'ai; Jiang, Tian

    2015-12-01

    By coupling black phosphorus (BP) nanoplatelets (NPs) with a fiber-taper evanescent light field, a saturable absorber (SA) based on the BP NPs has been successfully fabricated and used in a thulium/holmium-doped fiber laser as the mode locker. The SA had a modulation depth of ∼9.8% measured at 1.93 μm. A stable mode-locking operation at 1898 nm was achieved with a pulse width of 1.58 ps and a fundamental mode-lock repetition rate of 19.2 MHz. By increasing the pump intensity, phenomena of multi-pulsing operations, including harmonic mode-locked states and soliton bunches, were obtained in the experiment, showing that the BP NPs possess an ultrafast optical response time. This work suggests that the BP NPs-based SA is potentially useful for ultrashort, pulsed laser operations in the eye-safe region of 2 μm. PMID:26836690

  4. All-fiber passively mode-locked Tm-doped NOLM-based oscillator operating at 2-μm in both soliton and noisy-pulse regimes.

    PubMed

    Li, Jianfeng; Zhang, Zuxing; Sun, Zhongyuan; Luo, Hongyu; Liu, Yong; Yan, Zhijun; Mou, Chengbo; Zhang, Lin; Turitsyn, Sergei K

    2014-04-01

    A self-starting all-fiber passively mode-locked Tm(3+)-doped fiber laser based on nonlinear loop mirror (NOLM) is demonstrated. Stable soliton pulses centered at 2017.33 nm with 1.56 nm FWHM were produced at a repetition rate of 1.514 MHz with pulse duration of 2.8 ps and pulse energy of 83.8 pJ. As increased pump power, the oscillator can also operate at noise-like (NL) regime. Stable NL pulses with coherence spike width of 341 fs and pulse energy of up to 249.32 nJ was achieved at a center wavelength of 2017.24 nm with 21.33 nm FWHM. To the best of our knowledge, this is the first 2 µm region NOLM-based mode-locked fiber laser operating at two regimes with the highest single pulse energy for NL pulses. PMID:24718163

  5. Noise-like femtosecond pulse in passively mode-locked Tm-doped NALM-based oscillator with small net anomalous dispersion

    NASA Astrophysics Data System (ADS)

    Liu, Shuo; Yan, Feng-Ping; Zhang, Lu-Na; Han, Wen-Guo; Bai, Zhuo-Ya; Zhou, Hong

    2016-01-01

    A passively mode-locked thulium-doped fiber laser (TDFL) based on a nonlinear amplifying loop mirror (NALM) is presented. By adjusting the polarization controllers, stable noise-like (NL) mode-locked femtosecond pulse operation is obtained at the 2 μm band. In the experimental period of 200 min, the output power fluctuation is less than 0.06 dB and the 3 dB spectral bandwidth variation is less than 0.02 nm, indicating that the pulsed TDFL possesses good long-term stability. To the best of our knowledge, this is the first 2 μm band NALM-based TDFL with small net anomalous dispersion for a NL femtosecond pulse. At the maximum pump power of 3.52 W, the emitting laser has a NL pulse width of 460 fs, the repetition rate of 9.1 MHz, and the NL pulse energy of 32.72 nJ.

  6. Generation of high energy square-wave pulses in all anomalous dispersion Er:Yb passive mode locked fiber ring laser.

    PubMed

    Semaan, Georges; Ben Braham, Fatma; Salhi, Mohamed; Meng, Yichang; Bahloul, Faouzi; Sanchez, François

    2016-04-18

    We have experimentally demonstrated square pulses emission from a co-doped Er:Yb double-clad fiber laser operating in anomalous dispersion DSR regime using the nonlinear polarization evolution technique. Stable mode-locked pulses have a repetition rate of 373 kHz with 2.27 µJ energy per pulse under a pumping power of 30 W in cavity. With the increase of pump power, both the duration and the energy of the output square pulses broaden. The experimental results demonstrate that the passively mode-locked fiber laser operating in the anomalous regime can also realize a high-energy pulse, which is different from the conventional low-energy soliton pulse. PMID:27137277

  7. Compression mechanism of subpicosecond pulses by malachite green dye in passively mode-locked rhodamine 6G/DODCI CW dye lasers

    SciTech Connect

    Watanabe, A.; Hara, M.; Kobayashi, H.; Takemura, H.; Tanaka, S.

    1983-04-01

    The pulse width compression effect of a malachite green (MG) dye upon subpicosecond pulses has been experimentally investigated in a CW passively mode-locked rhodamine 6G/DODCI dye laser. The pulse width reduces as MG concentration increases, and reaches 0.34 ps at 1.5 X 10/sup -6/ M. By adding the MG dye, good mode locking is achieved in a rather wide pumping-power range. A computer simulation of pulse growth has also been carried out by using simple rate equations, in which the fast-recovery component of loss due to the MG dye is taken into account. The simulated results can explain some experimental results qualitatively such as pulse width compression and pumping-power restriction. The pulse width compression results essentially from the fast recovery of cavity loss caused by the MG dye.

  8. Modeling of beam width in passively Q-switched end-pumped lasers.

    PubMed

    Jabczyński, Jan; Kwiatkowski, Jacek; Zendzian, Waldemar

    2003-03-24

    An iterative model based on the LambertW function was developed for estimating the fundamental mode parameters of resonators with saturable gain guiding. The process of pulse buildup in passively Qswitched, end-pumped lasers was analyzed. The effective ABCD cavity matrix for consecutive round-trips was calculated, taking into account spatially variable saturated gain in an active medium and absorption bleaching in a saturable absorber. The twofold decrease in beam width, as compared with the fundamental mode of the bare cavity, was demonstrated. The application of such a model for resonators with other nonlinear elements is feasible. PMID:19461764

  9. Free-standing nano-scale graphite saturable absorber for passively mode-locked erbium doped fiber ring laser Free-standing nano-scale graphite saturable absorber

    NASA Astrophysics Data System (ADS)

    Lin, Y.-H.; Lin, G.-R.

    2012-05-01

    The free-standing graphite nano-particle located between two FC/APC fiber connectors is employed as the saturable absorber to passively mode-lock the ring-type Erbium-doped fiber laser (EDFL). The host-solvent-free graphite nano-particles with sizes of 300 - 500 nm induce a comparable modulation depth of 54%. The interlayer-spacing and lattice fluctuations of polished graphite nano-particles are observed from the weak 2D band of Raman spectrum and the azimuth angle shift of -0.32° of {002}-orientation dependent X-ray diffraction peak. The graphite nano-particles mode-locked EDFL generates a 1.67-ps pulsewidth at linearly dispersion-compensated regime with a repetition rate of 9.1 MHz. The time-bandwidth product of 0.325 obtained under a total intra-cavity group-delay-dispersion of -0.017 ps2 is nearly transform-limited. The extremely high stability of the nano-scale graphite saturable absorber during mode-locking is observed at an intra-cavity optical energy density of 7.54 mJ/cm2. This can be attributed to its relatively high damage threshold (one order of magnitude higher than the graphene) on handling the optical energy density inside the EDFL cavity. The graphite nano-particle with reduced size and sufficient coverage ratio can compete with other fast saturable absorbers such as carbon nanotube or graphene to passively mode-lock fiber lasers with decreased insertion loss and lasing threshold.

  10. Performance enhancement of sub-nanosecond diode-pumped passively Q-switched Yb:YAG microchip laser with diamond surface cooling.

    PubMed

    Zhuang, W Z; Chen, Yi-Fan; Su, K W; Huang, K F; Chen, Y F

    2012-09-24

    We experimentally confirm that diamond surface cooling can significantly enhance the output performance of a sub-nanosecond diode-end-pumped passively Q-switched Yb:YAG laser. It is found that the pulse energy obtained with diamond cooling is approximately 1.5 times greater than that obtained without diamond cooling, where a Cr(4+):YAG absorber with the initial transmission of 84% is employed. Furthermore, the standard deviation of the pulse amplitude peak-to-peak fluctuation is found to be approximately 3 times lower than that measured without diamond cooling. Under a pump power of 3.9 W, the passively Q-switched Yb:YAG laser can generate a pulse train of 3.3 kHz repetition rate with a pulse energy of 287 μJ and with a pulse width of 650 ps. PMID:23037409

  11. Evaluation of a commercially available passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber for laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Carson, Cantwell G.; Goueguel, Christian L.; Sanghapi, Hervé; Jain, Jinesh; McIntyre, Dustin

    2016-05-01

    Interest in passively Q-switched microchip lasers as a means for miniaturization of laser-induced breakdown spectroscopy (LIBS) apparatus has rapidly grown in the last years. To explore the possibility of using a comparatively UV-vis transparent absorber, we herein present the first report on the evaluation of a commercially available flash lamp-pumped passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber as an excitation source in LIBS. Quantitative measurements of barium, strontium, rubidium and lithium in granite, rhyolite, basalt and syenite whole-rock glass samples were performed. Using a gated intensified benchtop spectrometer, limits of detection of 0.97, 23, 37, and 144 ppm were obtained for Li, Sr, Rb, and Ba, respectively. Finally, we discuss the advantages of using such a laser unit for LIBS applications in terms of ablation efficiency, analytical performances, output energy, and standoff capabilities.

  12. Nanosecond pulse passively Q-switched Yb-doped fiber laser with Cr4+: YAG as saturable absorber

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Liu, Jiang; Wang, Pu

    2011-06-01

    We report a passively Q-switched Yb-doped fiber laser with Cr4+:YAG saturable absorber and get stable nanosecond pulse trains. Three kinds of laser cavity configurations, including a cladding-pumped ring cavity, a cladding-pumped linear cavity and a core-pumped linear cavity were studied, and they all can effectively restrain the generation of Stimulated Brillouin scattering and the generation of self-pulse. Cladding-pumped ring-avity fiber laser with Cr4+:YAG as saturable absorber inside is established for the first time to obtain stable 1 μs pulse trains. The amplitude fluctuation and timing jitter are below 5% (rms). Further more, we can also get stable pulse trains by using a high reflective fiber Bragging grating as a resonator mirror in a cladding-pumped linear cavity and a core-pumped linear cavity fiber laser respectively. In the cladding-pumped linear cavity fiber laser, the tunable pulse repetition rate is from 9.1 kHz to 30.3 kHz and the minimum pulse duration is 156 ns. And in the core-pumped linear cavity fiber laser, the tunable pulse repetition rate is from 15 kHz to 33 kHz and the minimum pulse duration is 24 ns which much less than those reported before. Although the average output power is only hundreds milli-Watts now, the laser uses a fiber coupler as the output of pulse trains, it is convinient to boost the power with a stage of fiber amplifier. This kind of pulse laser can be used as a seed source, and amplified to tens of Watts for practical applications in the future.

  13. Wall paper single-walled carbon nanotubes absorber for passively mode-locked Nd: GdVO4 laser

    NASA Astrophysics Data System (ADS)

    Wang, Yong Gang; Chen, Hou Ren; Wen, Xiao Min; Hsieh, Wen Feng; Tang, Jau

    2012-04-01

    A novel and low-cost wall paper single-walled carbon nanotubes (SWCNTs) absorber was fabricated by high viscosity of polyvinyl alcohol (PVA) aqueous solution and vertical evaporation technique. Sandwich structure wall paper SWCNT (SSWA-SWCNT) absorber was constructed by a piece of wall paper SWCNT absorber, a piece of round quartz and an output coupler mirror. We exploited it to realize mode locking operation in a diode-pumped Nd: GdVO4 laser. A pulse duration of 9.6 ps was produced with an average power of 870 mW. The stable mode locking operation was obtained when the average power is less than 300 mW.

  14. Efficiency of non-linear frequency conversion of double-scale pico-femtosecond pulses of passively mode-locked fiber laser.

    PubMed

    Smirnov, Sergey V; Kobtsev, Sergey M; Kukarin, Sergey V

    2014-01-13

    For the first time we report the results of both numerical simulation and experimental observation of second-harmonic generation as an example of non-linear frequency conversion of pulses generated by passively mode-locked fiber master oscillator in different regimes including conventional (stable) and double-scale (partially coherent and noise-like) ones. We show that non-linear frequency conversion efficiency of double-scale pulses is slightly higher than that of conventional picosecond laser pulses with the same energy and duration despite strong phase fluctuations of double-scale pulses. PMID:24515065

  15. High-power 880-nm diode-directly-pumped passively mode-locked Nd:YVO₄ laser at 1342 nm with a semiconductor saturable absorber mirror.

    PubMed

    Li, Fang-Qin; Liu, Ke; Han, Lin; Zong, Nan; Bo, Yong; Zhang, Jing-Yuan; Peng, Qin-Jun; Cui, Da-Fu; Xu, Zu-Yan

    2011-04-15

    A high-power 880-nm diode-directly-pumped passively mode-locked 1342 nm Nd:YVO₄ laser was demonstrated with a semiconductor saturable absorber mirror (SESAM). The laser mode radii in the laser crystal and on the SESAM were optimized carefully using the ABCD matrix formalism. An average output power of 2.3 W was obtained with a repetition rate of 76 MHz and a pulse width of 29.2 ps under an absorbed pump power of 12.1 W, corresponding to an optical-optical efficiency of 19.0% and a slope efficiency of 23.9%, respectively. PMID:21499398

  16. Passive mode locking of an in-band-pumped Ho:YLiF4 laser at 2.06 μm.

    PubMed

    Coluccelli, Nicola; Lagatsky, Alexander; Di Lieto, Alberto; Tonelli, Mauro; Galzerano, Gianluca; Sibbett, Wilson; Laporta, Paolo

    2011-08-15

    We demonstrate the passive mode-locking operation of an in-band-pumped Ho:YLiF(4) laser at 2.06 μm using a semiconductor saturable absorber mirror based on InGaAsSb quantum wells. A transform-limited pulse train with minimum duration of 1.1 ps and average power of 0.58 W has been obtained at a repetition frequency of 122 MHz. A maximum output power of 1.7 W has been generated with a corresponding pulse duration of 1.9 ps. PMID:21847210

  17. Passively mode-locked pulse generation in a c-cut Nd:LuVO4 laser at 1086 nm with a semiconductor saturable-absorber mirror

    NASA Astrophysics Data System (ADS)

    Lin, Ja-Hon; Yang, Pao-Keng; Lin, Wei-Cheng

    2012-04-01

    We demonstrate a diode-pumped passively mode-locked (ML) c-cut Nd:LuVO4 laser with central wavelength at 1086 nm by shifting the reflectance band of the SESAM into a longer wavelength to result in larger loss around 1068 nm. At 15 W absorbed pump power, the highest output power of the ML pulse was about 2.6 W that corresponded to the 17.3% optical-to-optical conversion efficiency and the slope efficiency of laser was about 22.9%. Using our ML laser as the light source, we have also successfully measured the saturation fluence of the SESAM at 1086 nm.

  18. High-efficiency 17 W, 80 MHz repetition rate, passively mode-locked TEM00 Nd:YAG oscillator pumped at 885 nm

    NASA Astrophysics Data System (ADS)

    Zhang, X.-F.; Li, F.-Q.; Zong, N.; Le, X.-Y.; Cui, D.-F.; Xu, Z.-Y.

    2011-03-01

    We report on a passively mode-locked TEM00 Nd:YAG oscillator with the beam quality at M 2 = 1.1 by a semiconductor saturable absorber mirror under 885 nm laser diode direct pumping for the first time. A maximum average output power of 17 W at a repetition rate of 80 MHz with 39 ps pulse width was obtained under the absorbed pump power of 38 W, corresponding to an optical-optical efficiency of 44% and the slope efficiency of 69%, respectively.

  19. PVP-Assisted Solvothermal Synthesis of High-Yielded Bi2Te3 Hexagonal Nanoplates: Application in Passively Q-Switched Fiber Laser.

    PubMed

    He, Xin; Zhang, Hang; Lin, Wei; Wei, Rongfei; Qiu, Jianrong; Zhang, Mei; Hu, Bin

    2015-01-01

    High-yielded Bi2Te3 hexagonal nanoplates were fabricated via a facile solvothermal method with the assistance of poly (vinyl pyrrolidone) (PVP). Effects of PVP molecular weight and concentration on the morphology and size distribution of the products were illustrated in this study. Molecular weight of PVP is significant for determining the morphology of Bi2Te3. The hexagonal nanoplates with high yield were obtained in the presence of PVP with molecular weight of 40000-45000. The average size and size distribution of Bi2Te3 nanoplates can be slightly varied by controlling concentration of PVP. High-yielded Bi2Te3 nanoplates exhibit characteristics of saturable absorption, identified by open-aperture Z-scan technique. The synthesized Bi2Te3 nanoplates with large saturation intensity of 4.6 GW/cm(2) and high modulation depth of 45.95% generated a stable passively Q-switched fiber laser pulse at 1.5 μm. In comparison with recently reported Q-switched fiber lasers utilizing exfoliated Bi2Te3 nanosheets, our passive Q-switching operations could be conducted at a relatively low threshold power of 30.2 mW or a quite high output power of 99.45 mW by tuning the cavity parameters. PMID:26511763

  20. PVP-Assisted Solvothermal Synthesis of High-Yielded Bi2Te3 Hexagonal Nanoplates: Application in Passively Q-Switched Fiber Laser

    PubMed Central

    He, Xin; Zhang, Hang; Lin, Wei; Wei, Rongfei; Qiu, Jianrong; Zhang, Mei; Hu, Bin

    2015-01-01

    High-yielded Bi2Te3 hexagonal nanoplates were fabricated via a facile solvothermal method with the assistance of poly (vinyl pyrrolidone) (PVP). Effects of PVP molecular weight and concentration on the morphology and size distribution of the products were illustrated in this study. Molecular weight of PVP is significant for determining the morphology of Bi2Te3. The hexagonal nanoplates with high yield were obtained in the presence of PVP with molecular weight of 40000–45000. The average size and size distribution of Bi2Te3 nanoplates can be slightly varied by controlling concentration of PVP. High-yielded Bi2Te3 nanoplates exhibit characteristics of saturable absorption, identified by open-aperture Z-scan technique. The synthesized Bi2Te3 nanoplates with large saturation intensity of 4.6 GW/cm2 and high modulation depth of 45.95% generated a stable passively Q-switched fiber laser pulse at 1.5 μm. In comparison with recently reported Q-switched fiber lasers utilizing exfoliated Bi2Te3 nanosheets, our passive Q-switching operations could be conducted at a relatively low threshold power of 30.2 mW or a quite high output power of 99.45 mW by tuning the cavity parameters. PMID:26511763

  1. Passive Q-switching of a Tm,Ho:KLu(WO4)2 microchip laser by a Cr:ZnS saturable absorber.

    PubMed

    Serres, J M; Loiko, P; Mateos, X; Jambunathan, V; Yasukevich, A S; Yumashev, K V; Petrov, V; Griebner, U; Aguiló, M; Díaz, F

    2016-05-10

    A diode-pumped Tm,Ho:KLu(WO4)2 microchip laser passively Q-switched with a Cr:ZnS saturable absorber generated an average output power of 131 mW at 2063.6 nm with a slope efficiency of 11% and a Q-switching conversion efficiency of 58%. The pulse characteristics were 14  ns/9  μJ at a pulse repetition frequency of 14.5 kHz. With higher modulation depth of the saturable absorber, 9  ns/10.4  μJ/8.2  kHz pulses were generated at 2061.1 nm, corresponding to a record peak power extracted from a passively Q-switched Tm,Ho laser of 1.15 kW. A theoretical model is presented, predicting the pulse energy and duration. The simulations are in good agreement with the experimental results. PMID:27168288

  2. PVP-Assisted Solvothermal Synthesis of High-Yielded Bi2Te3 Hexagonal Nanoplates: Application in Passively Q-Switched Fiber Laser

    NASA Astrophysics Data System (ADS)

    He, Xin; Zhang, Hang; Lin, Wei; Wei, Rongfei; Qiu, Jianrong; Zhang, Mei; Hu, Bin

    2015-10-01

    High-yielded Bi2Te3 hexagonal nanoplates were fabricated via a facile solvothermal method with the assistance of poly (vinyl pyrrolidone) (PVP). Effects of PVP molecular weight and concentration on the morphology and size distribution of the products were illustrated in this study. Molecular weight of PVP is significant for determining the morphology of Bi2Te3. The hexagonal nanoplates with high yield were obtained in the presence of PVP with molecular weight of 40000-45000. The average size and size distribution of Bi2Te3 nanoplates can be slightly varied by controlling concentration of PVP. High-yielded Bi2Te3 nanoplates exhibit characteristics of saturable absorption, identified by open-aperture Z-scan technique. The synthesized Bi2Te3 nanoplates with large saturation intensity of 4.6 GW/cm2 and high modulation depth of 45.95% generated a stable passively Q-switched fiber laser pulse at 1.5 μm. In comparison with recently reported Q-switched fiber lasers utilizing exfoliated Bi2Te3 nanosheets, our passive Q-switching operations could be conducted at a relatively low threshold power of 30.2 mW or a quite high output power of 99.45 mW by tuning the cavity parameters.

  3. High-power CW and passively Q-switched laser operation of Yb:GdCa4O(BO3)3 crystal

    NASA Astrophysics Data System (ADS)

    Chen, Xiaowen; Wang, Lisha; Liu, Junhai; Guo, Yunfeng; Han, Wenjuan; Xu, Honghao; Yu, Haohai; Zhang, Huaijin

    2016-05-01

    We demonstrate efficient high-power CW and passively Q-switched operations of Yb:GdCa4O(BO3)3 lasers. An output power of 18.2 W is generated at 1031.5 nm in CW mode, with optical-to-optical and slope efficiencies being respectively 55% and 70%, with respect to incident pump power. In passively Q-switched operation with a Cr4+:YAG crystal as saturable absorber, a maximum average output power of 15.6 W is produced at a pulse repetition rate of 91 kHz, with an optical-to-optical efficiency of 44%. Low-repetition-rate Q-switched action is also realized, generating an average output power of 4.2 W at 5.7 kHz, the resulting pulse energy and duration are 737 μJ and 3.6 ns, leading to a peak power amounting to 205 kW.

  4. 2.78 μm passively Q-switched Er3+-doped ZBLAN fiber laser based on PLD-Fe2+:ZnSe film

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Feng, Guoying; Zhang, Hong; Yang, Xianheng; Dai, Shenyu; Zhou, Shouhuan

    2016-07-01

    Based on the pulsed laser deposition (PLD) method, we first fabricated a mid-infrared Fe2+:ZnSe film saturable absorber (SA). By employing the PLD Fe2+:ZnSe film SA, we have demonstrated a passively Q-switched double-clad Er3+-doped ZBLAN fiber laser operating at a wavelength of 2.78 μm. Stable Q-switched pulses with pulse energy of 7.98 μJ and pulse duration of 0.742 μs, corresponding to a peak power of 10.76 W, were obtained at a repetition rate of 102.94 kHz. The maximum average output power is 822 mW. Our results demostrate that the PLD-Fe2+:ZnSe film SA is promising for high power pulse generation in compact mid-infrared fiber lasers.

  5. Bi2Te3 based passively Q-switched fiber laser with cylindrical vector beam emission.

    PubMed

    Yan, Ke; Lin, Jian; Zhou, Yong; Gu, Chun; Xu, Lixin; Wang, Anting; Yao, Peijun; Zhan, Qiwen

    2016-04-10

    We report a passively Q-switched fiber laser with cylindrical vector beam output modes using a few-mode fiber Bragg grating as a polarization-selective output coupler and Bi2Te3 as the saturable absorber. Both radially and azimuthally polarized beams can be readily generated, and the output polarization can be switchable by tuning the polarization controllers inside the laser cavity. The repetition rate of the Q-switched laser can be tuned from 31.54 to 49.40 kHz when the pump power increases from 103.5 to 139.5 mW. The fiber laser operates at a single wavelength of 1557.5 nm with a 3 dB linewidth of <0.04  nm. PMID:27139870

  6. Laser based analysis using a passively Q-switched laser employing analysis electronics and a means for detecting atomic optical emission of the laser media

    DOEpatents

    Woodruff, Steven D.; Mcintyre, Dustin L.

    2016-03-29

    A device for Laser based Analysis using a Passively Q-Switched Laser comprising an optical pumping source optically connected to a laser media. The laser media and a Q-switch are positioned between and optically connected to a high reflectivity mirror (HR) and an output coupler (OC) along an optical axis. The output coupler (OC) is optically connected to the output lens along the optical axis. A means for detecting atomic optical emission comprises a filter and a light detector. The optical filter is optically connected to the laser media and the optical detector. A control system is connected to the optical detector and the analysis electronics. The analysis electronics are optically connected to the output lens. The detection of the large scale laser output production triggers the control system to initiate the precise timing and data collection from the detector and analysis.

  7. High-peak-power flashlamp-pumped passively Q-switched Nd:YAG laser with AlGaInAs quantum wells as a saturable absorbers

    NASA Astrophysics Data System (ADS)

    Liang, H. C.; Huang, J. Y.; Huang, S. C.; Su, K. W.; Chen, Y. F.; Huang, K. F.

    2008-02-01

    We demonstrate an AlGaInAs saturable absorber with a periodic quantum wells (QWs)/barrier structure that can be used to achieve an efficient high-peak-power and high-pulse-energy passively flashlamp-pumped Q-switched Nd:YAG laser at 1.06 um. The barrier layers are designed to locate the QW groups in the region of the nodes of the lasing standing wave to avoid damage. With an incident pump voltage of 14.5 J, a single pulse was generated with a pulse energy of 14 mJ and a Q-switched pulse width of 13 ns. The maximum peak power was greater than 1.08 MW.

  8. 808-nm diode-pumped dual-wavelength passively Q-switched Nd:LuLiF4 laser with Bi-doped GaAs

    NASA Astrophysics Data System (ADS)

    Li, S. X.; Li, T.; Li, D. C.; Zhao, S. Z.; Li, G. Q.; Hang, Y.; Zhang, P. X.; Li, X. Y.; Qiao, H.

    2015-09-01

    Diode-pumped CW and passively Q-switched Nd:LuLiF4 lasers with stable, synchronous dual-wavelength operations near 1047 and 1053 nm were demonstrated for the first time. The maximal CW output power of 821 mW was obtained at an incident pump power of 6.52 W. Employing high quality Bi-doped GaAs as saturable absorber, stable dual-wavelength Q-switched operation was realized. Under 6.52 W incident pump power, the minimal pulse duration of 1.5 ns, the largest single pulse energy of 11.32 μJ, and the highest peak power of 7.25 kW were achieved.

  9. Experimental study on the self-mode-locked Ti:sapphire laser

    NASA Astrophysics Data System (ADS)

    Qi-rong, Xing; Wei-li, Zhang; Wei, Lu; Yoo, K. M.; Lueng, J.

    1996-01-01

    The role of gain aperture in self-mode-locked Ti:sapphire laser was verified in our experiments. The observation of self-Q switching of self-mode-locked Ti:sapphire laser is reported. And tuning pulse duration from 50 fs to 14.5 ps was achieved.

  10. Numerical analysis of a broadband spectrum generated in a standard fiber by noise-like pulses from a passively mode-locked fiber laser

    NASA Astrophysics Data System (ADS)

    Hernandez-Garcia, J. C.; Pottiez, O.; Estudillo-Ayala, J. M.; Rojas-Laguna, R.

    2012-04-01

    This paper covers a numerical analysis of supercontinuum spectrum generation in a piece of standard fiber by using as the pump noise-like pulses produced by a passively mode-locked fiber laser. An experimental study was also carried out, yielding results that support the numerical results. In the numerical study we estimated that the spectral extension of the generated supercontinuum reaches ~ 1000 nm, and that it presents a high flatness over a region of ~ 220 nm (1630 nm-1850 nm) when we use as the pump noise-like pulses with a wide optical bandwidth (~ 50 nm) and a peak power of ~ 2 kW. Experimentally, the output signal spectrum extends from ~ 1530 nm to at least 1750 nm and presents a high flatness over a region of 1640 nm to 1750 nm for the same value of numerical input power, 1750 nm being the upper limit of the optical spectrum analyzer. The numerical analysis presented here is thus an essential part to overcome the severe limitation in measuring capabilities and to understand the phenomena of supercontinuum generation, which is mainly related to Raman self-frequency shift. Finally, this work demonstrates the potential of noise-like pulses from a passively mode-locked fiber laser for broadband spectrum generation.

  11. Widely-tunable, passively Q-switched erbium-doped fiber laser with few-layer MoS2 saturable absorber.

    PubMed

    Huang, Yizhong; Luo, Zhengqian; Li, Yingyue; Zhong, Min; Xu, Bin; Che, Kaijun; Xu, Huiying; Cai, Zhiping; Peng, Jian; Weng, Jian

    2014-10-20

    We propose and demonstrate a MoS2-based passively Q-switched Er-doped fiber laser with a wide tuning range of 1519.6-1567.7 nm. The few-layer MoS2 nano-platelets are prepared by the liquid-phase exfoliation method, and are then made into polymer-composite film to construct the fiber-compatible MoS2 saturable absorber (SA). It is measured at 1560 nm wavelength, that such MoS2 SA has the modulation depth of ∼ 2% and the saturable optical intensity of ∼ 10 MW/cm(2). By further inserting the filmy MoS2-SA into an Er-doped fiber laser, stable Q-switching operation with a 48.1 nm continuous tuning from S- to C-waveband is successfully achieved. The shortest pulse duration and the maximum pulse energy are 3.3 μs and 160 nJ, respectively. The repetition rate and the pulse duration under different operation conditions have been also characterized. To the best of our knowledge, it is the first demonstration of MoS2 Q-switched, widely-tunable fiber laser. PMID:25401559

  12. Erbium-doped fiber laser passively mode locked with few-layer WSe2/MoSe2 nanosheets.

    PubMed

    Mao, Dong; She, Xiaoyang; Du, Bobo; Yang, Dexing; Zhang, Wending; Song, Kun; Cui, Xiaoqi; Jiang, Biqiang; Peng, Tao; Zhao, Jianlin

    2016-01-01

    Few-layer transition-metal dichalcogenide WSe2/MoSe2 nanosheets are fabricated by a liquid exfoliation technique using sodium deoxycholate bile salt as surfactant, and their nonlinear optical properties are investigated based on a balanced twin-detector measurement scheme. It is demonstrated that both types of nanosheets exhibit nonlinear saturable absorption properties at the wavelength of 1.55 μm. By depositing the nanosheets on side polished fiber (SPF) or mixing the nanosheets with polyvinyl alcohol (PVA) solution, SPF-WSe2 saturable absorber (SA), SPF-MoSe2 SA, PVA-WSe2 SA, and PVA-MoSe2 SA are successfully fabricated and further tested in erbium-doped fiber lasers. The SPF-based SA is capable of operating at the high pump regime without damage, and a train of 3252.65 MHz harmonically mode-locked pulses are obtained based on the SPF-WSe2 SA. Soliton mode locking operations are also achieved in the fiber laser separately with other three types of SAs, confirming that the WSe2 and MoSe2 nanosheets could act as cost-effective high-power SAs for ultrafast optics. PMID:27010509

  13. Erbium-doped fiber laser passively mode locked with few-layer WSe2/MoSe2 nanosheets

    NASA Astrophysics Data System (ADS)

    Mao, Dong; She, Xiaoyang; Du, Bobo; Yang, Dexing; Zhang, Wending; Song, Kun; Cui, Xiaoqi; Jiang, Biqiang; Peng, Tao; Zhao, Jianlin

    2016-03-01

    Few-layer transition-metal dichalcogenide WSe2/MoSe2 nanosheets are fabricated by a liquid exfoliation technique using sodium deoxycholate bile salt as surfactant, and their nonlinear optical properties are investigated based on a balanced twin-detector measurement scheme. It is demonstrated that both types of nanosheets exhibit nonlinear saturable absorption properties at the wavelength of 1.55 μm. By depositing the nanosheets on side polished fiber (SPF) or mixing the nanosheets with polyvinyl alcohol (PVA) solution, SPF-WSe2 saturable absorber (SA), SPF-MoSe2 SA, PVA-WSe2 SA, and PVA-MoSe2 SA are successfully fabricated and further tested in erbium-doped fiber lasers. The SPF-based SA is capable of operating at the high pump regime without damage, and a train of 3252.65 MHz harmonically mode-locked pulses are obtained based on the SPF-WSe2 SA. Soliton mode locking operations are also achieved in the fiber laser separately with other three types of SAs, confirming that the WSe2 and MoSe2 nanosheets could act as cost-effective high-power SAs for ultrafast optics.

  14. Erbium-doped fiber laser passively mode locked with few-layer WSe2/MoSe2 nanosheets

    PubMed Central

    Mao, Dong; She, Xiaoyang; Du, Bobo; Yang, Dexing; Zhang, Wending; Song, Kun; Cui, Xiaoqi; Jiang, Biqiang; Peng, Tao; Zhao, Jianlin

    2016-01-01

    Few-layer transition-metal dichalcogenide WSe2/MoSe2 nanosheets are fabricated by a liquid exfoliation technique using sodium deoxycholate bile salt as surfactant, and their nonlinear optical properties are investigated based on a balanced twin-detector measurement scheme. It is demonstrated that both types of nanosheets exhibit nonlinear saturable absorption properties at the wavelength of 1.55 μm. By depositing the nanosheets on side polished fiber (SPF) or mixing the nanosheets with polyvinyl alcohol (PVA) solution, SPF-WSe2 saturable absorber (SA), SPF-MoSe2 SA, PVA-WSe2 SA, and PVA-MoSe2 SA are successfully fabricated and further tested in erbium-doped fiber lasers. The SPF-based SA is capable of operating at the high pump regime without damage, and a train of 3252.65 MHz harmonically mode-locked pulses are obtained based on the SPF-WSe2 SA. Soliton mode locking operations are also achieved in the fiber laser separately with other three types of SAs, confirming that the WSe2 and MoSe2 nanosheets could act as cost-effective high-power SAs for ultrafast optics. PMID:27010509

  15. Applications of single-walled carbon nanotubes and type-II quantum dots in photovoltaics and passive mode-locking saturable absorbers

    NASA Astrophysics Data System (ADS)

    Tang, Jau; Wang, Yong-Gang; Cheng, Shin-Min; Yu, Pyng; Huang, Kuo-Yen; Yuan, Chi-Tsu

    2012-10-01

    Using single-molecule confocal imaging techniques combined with time-correlated single-photon counting we investigated the electron transfer (ET) rates to the single-walled carbon nanotubes from various types of semiconductor hetero-nanocrystals of type-I or type-II band alignment. We observed significantly larger ET rate for type-II ZnSe/CdS dot-in-rod nanostructures as compared to type-I spherical CdSe/ZnS core/shell quantum-dots, and to CdSe/CdS dot-in-rod structures. We demonstrated that such rapid ET dynamics can compete with both Auger and radiative recombination processes, leading to potentially more effective photovoltaic operation. In another work, we used aligned single-walled carbon nanotubes as saturable absorbers for ps laser pulse generation. Using the vertical evaporation technique we fabricated saturable absorbers by transferring the water-soluble single wall carbon nanotubes onto a hydrophilic quartz substrate. The fast recovery times of the absorber were measured to be 136 fs and 790 fs. The modulation depth of the absorber was about 1.5%. Passive mode-locked Nd: GdVO4 laser using such an absorber was demonstrated. The continuous wave mode-locked pulses with the pulse duration of 12.4 ps and the repetition of 120 MHz were achieved. The maximum average output power of the mode-locked laser is 2.4 W at the pump power of 13 W. Such a kind of absorbers has potential to be put into practical use.

  16. Optical frequency comb generator based on a monolithically integrated passive mode-locked ring laser with a Mach-Zehnder interferometer.

    PubMed

    Corral, V; Guzmán, R; Gordón, C; Leijtens, X J M; Carpintero, G

    2016-05-01

    We report the demonstration of an optical-frequency comb generator based on a monolithically integrated ring laser fabricated in a multiproject wafer run in an active/passive integration process in a generic foundry using standardized building blocks. The device is based on a passive mode-locked ring laser architecture, which includes a Mach-Zehnder interferometer to flatten the spectral shape of the comb output. This structure allows monolithic integration with other optical components, such as optical filters for wavelength selection, or dual wavelength lasers for their stabilization. The results show a -10  dB span of the optical comb of 8.7 nm (1.08 THz), with comb spacing of 10.16 GHz. We also obtain a flatness of 44 lines within a 1.8 dB power variation. PMID:27128043

  17. High-peak-power, short-pulse-width, LD end-pumped, passively Q-switched Nd:YAG 946 nm laser

    NASA Astrophysics Data System (ADS)

    Yan, Renpeng; Yu, Xin; Ma, Yufei; Li, Xudong; Chen, Deying; Yu, Junhua

    2012-10-01

    High-peak-power, short-pulse-width diode pumped 946 nm Nd:YAG laser in passively Q-switching operation with Cr4+:YAG is reported. The highest average output power reaches 3.4 W using the Cr4+:YAG with initial transmissivity T0=95%. When the T0=90% Cr4+:YAG is employed, the maximum peak power of 31.4 kW with a pulse width of 8.3 ns at 946 nm is generated.

  18. Diode-pumped Nd:YAG ceramic laser at 946 nm passively Q-switched with a Cr 4+:YAG saturable absorber

    NASA Astrophysics Data System (ADS)

    Li, Ping; Zhang, Huanian; Chen, Xiaohan; Wang, Qingpu

    2012-04-01

    We demonstrate a diode-pumped Nd:YAG ceramic laser with emission at 946 nm that is passively Q-switched by single-crystal Cr 4+:YAG saturable absorber. An average output power of 1.7 W is measured under 18.4 W of incident power using an output mirror with transmission T=4%. The corresponding optical-to-optical efficiency is 9.2%. The laser runs at a pulse repetition rate of 120 kHz and delivers pulses with energy of 14 μJ and duration of 80 ns, which corresponds to a peak power of 175 W.

  19. Generation of high-peak power 532-nm green pulses from composite, all-ceramics, passively Q-switched Nd:YAG/Cr4+:YAG laser

    NASA Astrophysics Data System (ADS)

    Salamu, Gabriela; Ionescu, Alina; Brandus, Catalina; Grigore, Oana; Pavel, Nicolaie; Dascalu, Traian

    2013-06-01

    Laser pulses at 1.06 μm with 2.5-mJ energy and 3.1-MW peak power have been obtained from a composite, all polycrystalline ceramics, passively Q-switched 1.1-at.% Nd:YAG/Cr4+:YAG laser that was quasi-continuous-wave pumped with diode lasers. Single-pass frequency doubling with LiB3O5 nonlinear crystal at room temperature yielded green laser pulses at 532 nm with energy of 0.36-mJ and 0.45-MW peak power; the infrared-to-green conversion efficiency was 0.27.

  20. Diode-pumped passively Q-switched Nd:YVO4 green laser with a periodically poled KTP and Cr4+:YAG saturable absorber.

    PubMed

    Li, Guiqiu; Zhao, Shengzhi; Yang, Kejian; Li, Dechun

    2006-03-10

    A diode-pumped passively Q-switched Nd:YVO4 green laser with a periodically poled KTP and Cr4+:YAG saturable absorber is realized. The dependences of pulse repetition rate, pulse energy, pulse width, and peak power on incident pump power are measured for the generated green-light pulses. A rate-equation model is introduced to theoretically analyze the results obtained in the experiment, in which the spatial distribution of the intracavity photon density is taken into account. The numerical solutions of the rate equations agree with the experimental results. PMID:16572700

  1. Lean-Burn Stationary Natural Gas Reciprocating Engine Operation with a Prototype Miniature Diode Side Pumped Passively Q-switched Laser Spark Plug

    SciTech Connect

    McIntyre, D.L.; Woodruff, S.D.; McMillian, M.H.; Richardson, S.W.; Gautam, Mridul

    2008-04-01

    To meet the ignition system needs of large bore lean burn stationary natural gas engines a laser diode side pumped passively Q-switched laser igniter was developed and used to ignite lean mixtures in a single cylinder research engine. The laser design was produced from previous work. The in-cylinder conditions and exhaust emissions produced by the miniaturized laser were compared to that produced by a laboratory scale commercial laser system used in prior engine testing. The miniaturized laser design as well as the combustion and emissions data for both laser systems was compared and discussed. It was determined that the two laser systems produced virtually identical combustion and emissions data.

  2. All solid-state mode-locked flashlamp pumped Nd:YAG laser system with selectable pulse duration

    NASA Astrophysics Data System (ADS)

    Kubecek, Vaclav; Diels, Jean-Claude; Stintz, Andreas; Jelinkova, Helena; Dombrovsky, Andrej; Cech, Miroslav

    2005-04-01

    All solid state mode-locked flashlamp pumped Nd:YAG laser system with selectable pulse duration was developed based on the oscillator where a single semiconductor structure containing a multiple-quantum-well was used as a saturable absorber for mode-locking, and energy limiter for passive negative feedback. Single pulse selection from various parts of extended 200 ns long Q-switched pulse train enables the changing of pulse duration before entering into three stages of laser amplifiers. Using of additional acousto-optic mode-locker, stability enhancement of the output pulses was obtained and the amplitude fluctuations were reduced below 5%. The exploitation of the solid state saturable absorber and limiter integrated in the single element improved significantly the long term characteristics of the laser system which can be therefore used for various applications as a satellite laser ranging, spectroscopy, or medicine.

  3. Passively mode-locked Yb:YAG thin-disk laser with pulse energies exceeding 13 microJ by use of an active multipass geometry.

    PubMed

    Neuhaus, Joerg; Kleinbauer, Jochen; Killi, Alexander; Weiler, Sascha; Sutter, Dirk; Dekorsy, Thomas

    2008-04-01

    We demonstrate the generation of high-energy picosecond pulses directly from a thin-disk laser oscillator by employing a self-imaging active multipass geometry. Stable single-pulse operation has been obtained with an average output power in excess of 50 W, excluding a cw background of 8%, at a repetition rate of 3.8 MHz. Self-starting passive mode locking was accomplished using a semiconductor saturable absorber mirror. The maximum pulse energy was 13.4 microJ at a pulse duration of 1.36 ps with a time-bandwidth product of 0.34. Single-pass external frequency doubling with a conversion efficiency of 60% yielded >28 W of average power at 515 nm. PMID:18382531

  4. The formation of various multi-soliton patterns and noise-like pulse in a fiber laser passively mode-locked by a topological insulator based saturable absorber

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Wu, Man; Tang, Pinghua; Chen, Shuqing; Du, Juan; Jiang, Guobao; Li, Ying; Zhao, Chujun; Zhang, Han; Wen, Shuangchun

    2014-05-01

    We experimentally investigated the formation of various multi-soliton patterns and noise-like (NL) pulses in an erbium-doped fiber laser passively mode-locked by a new type of saturable absorber: topological insulator. With the increase of pump power, various multi-soliton operation states—ordered, chaotic and bunched multiple-soliton—were subsequently obtained. Once the pump power exceeds 401 mW, an NL pulse state emerged, with a maximum 3 dB bandwidth of about 9.3 nm. This systematic study clearly demonstrated that a topological insulator could be an effective saturable absorber for the formation of various soliton operation states in a fiber laser cavity.

  5. Passive synchronization between a self-similar pulse and a bound-soliton bunch in a two-color mode-locked fiber laser.

    PubMed

    Hsiang, Wei-Wei; Chang, Chia-Hao; Cheng, Chien-Po; Lai, Yinchieh

    2009-07-01

    We report the first (to our knowledge) experimental observation of passive synchronization between a 1.03 microm self-similar pulse and a 1.56 microm bound-soliton bunch in a two-color mode-locked fiber laser. The self-similar pulse can form an effective potential well of several picoseconds to trap the copropagating bound solitons in the shared-fiber section. Such synchronization mechanism is supported by the experimental evidence of smaller time separation between the bound solitons under synchronization. In addition, the self-similar pulse and bound solitons can still remain locked under the periodic collision of another 1.56 microm unlocked pulse train. PMID:19571968

  6. Generation of "gigantic" ultra-short microwave pulses based on passive mode-locking effect in electron oscillators with saturable absorber in the feedback loop

    NASA Astrophysics Data System (ADS)

    Ginzburg, N. S.; Denisov, G. G.; Vilkov, M. N.; Zotova, I. V.; Sergeev, A. S.

    2016-05-01

    A periodic train of powerful ultrashort microwave pulses can be generated in electron oscillators with a non-linear saturable absorber installed in the feedback loop. This method of pulse formation resembles the passive mode-locking widely used in laser physics. Nevertheless, there is a specific feature in the mechanism of pulse amplification when consecutive energy extraction from different fractions of a stationary electron beam takes place due to pulse slippage over the beam caused by the difference between the wave group velocity and the electron axial velocity. As a result, the peak power of generated "gigantic" pulses can exceed not only the level of steady-state generation but also, in the optimal case, the power of the driving electron beam.

  7. Compact diode-directly-pumped passively mode-locked TEM00 Nd:GdVO4 laser at 1341 nm using a semiconductor saturable absorber mirror

    NASA Astrophysics Data System (ADS)

    Liu, K.; Li, F. Q.; Liu, Y.; Cao, D.; Bo, Y.; Peng, Q. J.; Cui, D. F.; Zhang, J. Y.; Xu, Z. Y.

    2011-11-01

    We report on a compact 880-nm diode-directly-pumped passively mode-locked TEM00 Nd:GdVO4 laser at 1341 nm with a semiconductor saturable absorber mirror (SESAM) for the first time. Under the absorbed pump power of 14.6 W, the maximum output power of 1.27 W was obtained at the repetition rate of 85.3 MHz with the pulse width of 45.3 ps, corresponding to an optical-optical efficiency of 8.8% and the slope efficiency of 33.3%, respectively. The beam quality factor was measured to be M 2 = 1.18, indicating a TEM00 mode.

  8. Pump beam waist-dependent pulse energy generation in Nd:YAG/Cr4+:YAG passively Q-switched microchip laser

    NASA Astrophysics Data System (ADS)

    Li, Chao-yu; Dong, Jun

    2016-08-01

    The incident pump beam waist-dependent pulse energy generation in Nd:YAG/Cr4+:YAG composite crystal passively Q-switched microchip laser has been investigated experimentally and theoretically by moving the Nd:YAG/Cr4+:YAG composite crystal along the pump beam direction. Highest pulse energy of 0.4 mJ has been generated when the Nd:YAG/Cr4+:YAG composite crystal is moved about 6 mm away from the focused pump beam waist. Laser pulses with pulse width of 1.7 ns and peak power of over 235 kW have been achieved. The theoretically calculated effective laser beam area at different positions of Nd:YAG/Cr4+:YAG composite crystal along the pump beam direction is in good agreement with the experimental results. The highest peak power can be generated by adjusting the pump beam waist incident on the Nd:YAG/Cr4+:YAG composite crystal to optimize the effective laser beam area in passively Q-switched microchip laser.

  9. Continuous wave and passively Q-switched laser performance of Nd:LuxGd3-xGa5O12 crystal at 1062 nm

    NASA Astrophysics Data System (ADS)

    Fu, X. W.; Jia, Z. T.; Yang, H.; Li, Y. B.; Yuan, D. S.; Zhang, B. T.; Dong, C. M.; He, J. L.; Tao, X. T.

    2012-12-01

    Continuous wave (CW) and passively Q-switched (PQS) laser properties at 1062 nm of the Nd:LuxGd3-xGa5O12 (Nd:LGGG) disordered crystal have been demonstrated. The doping concentrations of Nd3+ and Lu3+ in the as obtained crystal were measured to be 0.96 and 0.66 at.%, respectively. In the CW regime, the output power of 9.73 W was obtained with an optical-to-optical efficiency as high as 60.7% and slope efficiency of 61.2%. During the passively Q-switched operation, the maximum output power of 1.24 W was achieved under the absorbed pump power of 6.86 W. The maximum peak power of 14.20 kW and single pulse energy of 148 μJ were obtained with the Toc = 10% under the absorbed pump power of 6.36 W. The results are much better than those obtained with Nd:LGGG crystal doped with 13.6 at.% Lu3+ and 0.53 at.% Nd3+ ions.

  10. Experimental and theoretical study of passively Q-switched Yb:YAG laser with GaAs saturable absorber near 1050 nm

    NASA Astrophysics Data System (ADS)

    Chu, Hongwei; Zhao, Shengzhi; Yang, Kejian; Li, Yuefei; Li, Dechun; Li, Guiqiu; Zhao, Jia; Qiao, Wenchao; Xu, Xiaodong; Di, Juqing; Zheng, Lihe; Xu, Jun

    2014-03-01

    A diode-end-pumped passively Q-switched ytterbium-doped yttrium aluminum garnet (Yb:YAG) laser with gallium arsenide (GaAs) wafer as saturable absorber has been realized. In the experiment, two pieces of GaAs wafers with respective thicknesses of 400 and 700 μm were used respectively. The output laser characteristics such as the pulse duration, single pulse energy and peak power, have been measured. By using thicker GaAs wafer as saturable absorber, a minimum pulse duration of 3.5 ns was obtained with an average output power of 361 mW and a pulse repetition rate (PRR) of 25 kHz, corresponding to a single pulse energy of 19.6 μJ and a peak power of 5.7 kW. With a 400 μm-thick GaAs wafer as saturable absorber, a maximum output power of 469 mW was achieved. The central wavelength of the laser was measured to be 1050.4 nm at pump power of 7.8 W and dual wavelength operation peaked at 1049.3 nm and 1051.6 nm was observed at a high pump power of 10 W. By considering Gaussian spatial distribution and the thermal effects in the gain medium, the coupled rate equations for passively Q-switched Yb:YAG laser with GaAs saturable absorber were given.