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Hongbin Shen, Qingpu Wang,
Xingyu Zhang,
Xiaohan Chen,
Fen Bai,
Zhaojun Liu,
Liang Gao,
Zhenhua Cong,
Zhenguo Wu,
Weitao Wang,
Yuangeng Zhang,
Weixia Lan,
Cong Wang
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ABSTRACT: A diode-pumped, actively Q-switched second-Stokes dual-wavelength laser employing ceramic Nd:YAG as the gain medium and BaWO<sub>4</sub> as the Raman medium is demonstrated. The dual-wavelength Raman laser emission at 1321 and 1325 nm is based on the dual-wavelength fundamental laser emission at 1061 and 1064 nm. With a pump power of 18.4 W and pulse repetition frequency of 15 kHz, a maximum dual-wavelength output power of 1.67 W was obtained, comprising a 0.75 W, 1321 nm laser component and a 0.92 W, 1325 nm laser component. The corresponding dual-wavelength second-Stokes pulse width was 2.9 ns.
Optics Letters 11/2012; 37(21):4519-21. · 3.40 Impact Factor
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Hongbin Shen, Qingpu Wang,
Xingyu Zhang,
Zhaojun Liu,
Fen Bai,
Zhenhua Cong,
Xiaohan Chen,
Zhenguo Wu,
Weitao Wang,
Liang Gao,
Weixia Lan
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ABSTRACT: A diode-pumped, actively Q-switched dual-wavelength laser employing Nd:YVO<sub>4</sub> self-Raman emission at 1524 nm and undoped GdVO<sub>4</sub> Raman emission at 1522 nm is demonstrated. With a pump power of 21.5 W and pulse repetition frequency of 20 kHz, a maximum dual-wavelength output power of 1.62 W was obtained, comprising a 0.54 W, 1522 nm Raman component and 1.08 W, 1524 nm self-Raman component. The corresponding dual-wavelength Raman pulse width was 5.6 ns. The experimental results indicate that this laser, with quite small wavelength separation, was effective by virtue of simultaneous self-Raman and Raman shifts.
Optics Letters 10/2012; 37(19):4113-5. · 3.40 Impact Factor
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ABSTRACT: 1st-Stokes and 2nd-Stokes dual-wavelength operation within a diode-side-pumped Q-switched Nd:YAG/BaWO<sub>4</sub> intracavity Raman laser was realized. Using an output coupler of transmission of 3.9% at 1180 nm and transmission of 60.08% at 1325 nm, the maximum output power of 8.30 W and 2.84 W at a pulse repetition rate of 15 kHz for the 1st Stokes and the 2nd Stokes laser were obtained, respectively. The corresponding optical conversion efficiency from diode laser to the 1st Stokes and 2nd Stokes laser are 5.0% and 1.4%, respectively. With the pump power of 209 W and a pulse repetition rate of 15 kHz, the 1st Stokes and the 2nd Stokes pulse widths were 20.5 ns and 5.8 ns, respectively. The stable simultaneous Q-switching and mode locking of the 2nd Stokes laser without mode locking component was obtained at the pump power of about 29~82 W. The estimated mode-locked pulse width was approximately 31 ps at the pump power of 50 W and a pulse repetition rate of 15 kHz.
Optics Express 07/2012; 20(16):17823-32. · 3.59 Impact Factor
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ABSTRACT: We demonstrate a tunable crystalline Raman laser by varying the temperature of Raman crystal. Nd:YAG and YVO(4) crystals were selected as the laser and Raman gain media, respectively. The center wavelength of this Nd:YAG/YVO(4) Raman laser was tuned over a 0.49 nm range from 1175.76 to 1175.27 nm when the temperature of the Raman crystal was adjusted from 5 °C to 150 °C. The characteristics of this Raman laser including tunability, output power, and beam quality factors (M(2)) dependent on temperature were also studied in this paper.
Optics Letters 07/2012; 37(13):2637-9. · 3.40 Impact Factor
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ABSTRACT: An acousto-optically Q-switched Nd:YVO(4)/KTiOAsO(4) (KTA) intracavity optical parametric oscillator (OPO) is efficiently realized in singly resonated scheme. With an end-pumping diode power of 25.9 W, output signal (1535 nm) power of 3.77 W and idler power (3467 nm) of 1.18 W are obtained at a pulse repetition rate of 50 kHz. A rate-equation model is set up to simulate the output power and time characteristics of both signal and idler waves. And both the numerical and experimental results show that the idler pulse width is shorter than the signal one in a singly resonant OPO.
Optics Express 01/2012; 20(2):807-15. · 3.59 Impact Factor
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ABSTRACT: We propose an all-fiber-optic supermode selection scheme based on large-mode-area single-mode fiber for multicore fiber (MCF). The supermode selection in terms of the coupling coefficient is investigated and compared for various ring-type and concentric-type MCFs. The in-phase supermode is found to have a significantly higher coupling coefficient than other supermodes--demonstrating significant and desirable supermode selection characteristics. This scheme has shown better in-phase supermode selection performance than the conventional free-space Talbot cavity. It is found to be effective in selecting the in-phase supermode for both ring-type and concentric-type MCFs and promising for all-fiber MCF lasers with high power output and good beam quality.
Journal of the Optical Society of America A 05/2011; 28(5):924-33. · 1.56 Impact Factor
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ABSTRACT: The rate equations for the quasi-three-level actively Q -switched lasers are obtained by considering the reabsorption of the lower laser level and the spatial distributions of the intracavity photon density and the population inversion density. These rate equations are normalized by introducing three new parameters. By solving the normalized rate equation numerically, a group of general curves is generated. These curves can give a good understanding of the dependences of the laser pulse characteristics on the new parameters. The curves and the related formulae can also be used to estimate the laser pulse characteristics of any quasi-three-level actively Q -switched laser. A sample calculation for a 946-nm actively Q -switched Nd:YAG ceramic laser is presented to demonstrate the use of the related formulae.
IEEE Journal of Quantum Electronics 05/2011; · 1.88 Impact Factor
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ABSTRACT: A 1.8 μm optical parametric oscillator (OPO) based on a noncritically phase-matched KTiOPO4 crystal is demonstrated. OPO and stimulated Raman scattering techniques are successfully combined in an acousto-optically Q-switched Nd:YAG/SrWO4 Raman laser. The device efficiently realizes three steps of conversion: from a laser diode wavelength of 808 nm to the fundamental wavelength of 1064 nm; next, to the Stokes wavelength of 1180 nm; and finally to the OPO signal wavelength of 1810 nm. With an incident diode power of 7.2 W and a pulse repetition rate of 15 kHz, an average signal power of 485 mW is obtained with a diode-to-signal conversion efficiency of 6.75%. The beam quality factors (M2) of the signal wave in both horizontal and vertical directions are measured to be 1.7±0.2. The numerical output power results of the system, the thermal lensing, and the stability parameter of the cavity are also discussed.
Optics Letters 03/2011; 36(6):813-5. · 3.40 Impact Factor
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Zhenhua Cong,
Dingyuan Tang,
Wei De Tan,
Jian Zhang,
Changwen Xu,
Dewei Luo,
Xiaodong Xu,
Dongzhen Li,
Jun Xu,
Xingyu Zhang, Qingpu Wang
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ABSTRACT: A diode-end-pumped dual-wavelength mode-locked laser based on Nd:LuYSiO5 crystal is demonstrated. With a SESAM, simultaneous mode locking at the 1075.8 nm and 1078.1 nm is achieved and the dual-wavelength mode locked pulses have a pulse width of 8.9 ps. Due to frequency beating, ultrahigh repetition rate ultrafast pulses with 997 fs pulse width and 0.59 THz repetition rate are further formed. Under 12.7 W absorbed pump power 1.7 W mode-locked output power was obtained, the slope efficiency of the mode locked laser was 24.3%.
Optics Express 02/2011; 19(5):3984-9. · 3.59 Impact Factor
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ABSTRACT: A diode-side-pumped actively Q-switched intracavity frequency-doubled Nd:YAG/BaWO(4)/KTP Raman laser is studied experimentally and theoretically. Rate equations are used to analyze the Q-switched yellow laser by considering the transversal distributions of the intracavity photon density and the inversion population density. An 8.3 W 590 nm laser is obtained with a 125.8 W 808 nm pump power and a 15 kHz pulse repetition frequency. The corresponding optical conversion efficiency from diode laser to yellow laser is 6.57%, much higher than that of the former reported side-pumped yellow laser. The output powers with respect to the incident pump power are in agreement with the theoretical results on the whole.
Optics Express 06/2010; 18(12):12111-8. · 3.59 Impact Factor
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ABSTRACT: Absorption coefficience of Tm<sup>3+</sup> ions in Tm<sup>3+</sup>/Yb<sup>3+</sup> codoped tellurite glass have been analyzed by using the J-O theory. The J-O parameters are calculated to be Ω 2 = 11.11×10<sup>−20</sup> cm<sup>2</sup>, Ω 4 = 3.5×10<sup>−20</sup> cm<sup>2</sup> and Ω 6 = 3.6×10<sup>−20</sup> cm<sup>2</sup>. Spontaneous radiative transition probabilities, branching ratios and radiative life time of Tm<sup>3+</sup> ions are also calculated, the calculation results indicate that it is difficult to get S-band amplification through single 808 nm laser pump in this glass, this is tested by 808 nm single wavelength pump experiment. The Yb<sup>3+</sup> codoping with Tm<sup>3+</sup> and energy transfer process between them make 980 nm single wavelength pump scheme possible to get S-band amplification, experiment results indicate that 980 nm pump energy absorbed by Yb<sup>3+</sup> is transferred to Tm<sup>3+</sup>, consequently, the low cost 980 nm pump scheme could make it become promising material for S-band amplification.
Communications and Photonics Conference and Exhibition (ACP), 2009 Asia; 12/2009
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ABSTRACT: An efficient intracavity frequency-doubled Raman laser was obtained by using an SrWO(4) Raman medium, an Nd:YAG ceramic gain medium, and a KTP frequency-doubling medium. Three laser cavities, including a two-mirror cavity, a three-mirror coupled cavity, and a folded cavity, were investigated. With the coupled cavity, a 2.93 W, 590 nm laser was obtained at an incident pump power of 16.2 W and a pulse repetition frequency of 20 kHz; the corresponding conversion efficiency was 18.1%. The highest conversion efficiency of 19.2% was obtained at an incident pump power of 14.1 W and a pulse repetition frequency of 15 kHz. The obtained maximum output power and conversion efficiency were much higher than the results previously obtained with intracavity frequency-doubled solid-state Raman lasers.
Optics Letters 10/2009; 34(17):2610-2. · 3.40 Impact Factor
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Zhaojun Liu, Qingpu Wang,
Xingyu Zhang,
Sasa Zhang,
Jun Chang,
Shuzhen Fan,
Wenjia Sun,
Guofan Jin,
Xutang Tao,
Youxuan Sun,
Shaojun Zhang,
Zejin Liu
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ABSTRACT: A self-frequency-doubled KTiOAsO4 (KTA) Raman laser is realized in a diode-end-pumped acousto-optically Q-switched intracavity Raman laser configuration. A 30-mm-long x-cut KTA crystal is used as the Raman medium, and its 671 cm(-1) Raman mode is employed to finish the conversion from 1064 nm fundamental laser to 1146 nm Raman laser. Self-frequency doubling of the Raman laser is accomplished in the same KTA crystal, and a 573 nm yellow laser is obtained. With an incident diode power of 10.9 W and a pulse repetition rate of 20.8 kHz, a yellow-laser power of 0.82 W is obtained. The conversion efficiency from diode power to yellow-laser power is 7.5%.
Optics Letters 07/2009; 34(14):2183-5. · 3.40 Impact Factor
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Zhaojun Liu, Qingpu Wang,
Xingyu Zhang,
Sasa Zhang,
Jun Chang,
Zhenhua Cong,
Wenjia Sun,
Guofan Jin,
Xutang Tao,
Youxuan Sun,
Shaojun Zhang
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ABSTRACT: A KTiOAsO(4) Raman laser is realized within a diode side-pumped acousto-optically Q-switched Nd:YAG laser. Efficient nanosecond first-Stokes generations at 1091.4 nm are obtained with three 30-mm-long KTA crystals. Under an incident diode power of 60.9 W and a pulse repetition rate of 4 kHz, a first-Stokes power of 4.55 W is obtained, corresponding to a diode-to-Stokes conversion efficiency of 7.5%. The single pulse energy is up to 1.14 mJ and the peak power is 18.0 kW.
Optics Express 05/2009; 17(9):6968-74. · 3.59 Impact Factor
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ABSTRACT: Photonic crystal (PhC) is a new class of material which has a periodic modulation of dielectric constant. PhC will exhibit superprism effect, negative refraction and self-collimating ultra-low group velocity due to the anomalous dispersion of PhC . We can utilize the characters of photonic bandgap(PBG), defect band, pass band and band edge to control the propagation of the light .This research was to investigate the refraction and superprism effect of photonic crystals .The study background and the basic theories of photonic crystals were introduced. The refraction of photonic crystals and superprism effect were discussed with the correlating knowledge and the computing methods. A new theory of light refraction at the surface of a photonic crystal was put forward and simulated. The simulating results of this application for negative refraction and superprism effect were demonstrated by some simulating figures. These may bring about important potential applications in some areas. Keywords: photonic crystal, superprism effect, simulation© (2009) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
02/2009;
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Zhaojun Liu, Qingpu Wang,
Xingyu Zhang,
Zejin Liu,
Jun Chang,
Hao Wang,
Sasa Zhang,
Shuzhen Fan,
Guofan Jin,
Xutang Tao,
Shaojun Zhang,
Huaijin Zhang
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ABSTRACT: Coexistent optical parametric oscillation (OPO) and stimulated Raman scattering (SRS) are demonstrated in an X-cut KTiOAsO(4) (KTA) crystal. The 30-mm-long KTA crystal is placed within a diode-end-pumped acousto-optically (AO) Q-switched Nd:YAG laser cavity to construct an intracavity optical parametric oscillator. Coexistent Raman conversion of the fundamental wave is observed from the KTA crystal. With a diode power of 7.43 W and a pulse repetition rate (PRR) of 20 kHz, a signal (1535.0 nm) power of 0.92 W is obtained, corresponding to a diode-tosignal conversion efficiency of 12.4%. A first-Stokes (1091.4 nm) power of 0.17 W is obtained.
Optics Express 11/2008; 16(21):17092-7. · 3.59 Impact Factor
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ABSTRACT: A vibration measuring system based on a matched-fiber Bragg grating (FBG) is demonstrated, and the cross sensitivity of the
temperature and strain was reduced by packaging the matched-sensing and interrogation FBG in the same shell, theory, system
structure, and experimental results are presented. The experimental results demonstrated that the system has a good response
to the 8–80 Hz vibration signal; it responds well to an acceleration of as low as 0.05 m/s2, the system was deployed in a coalmine, and good experimental result were received. Because the system has the advantage
of intrinsic safety and an easy multiplex, it has good prospects in the mining and petrochemical industry.
Laser Physics 06/2008; 18(7):911-913. · 3.61 Impact Factor
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Zhaojun Liu, Qingpu Wang,
Xingyu Zhang,
Zejin Liu,
Jun Chang,
Hao Wang,
Shuzhen Fan,
Shutao Li,
Shuaishuai Huang,
Wenjia Sun,
Guofan Jin,
Xutang Tao,
Shaojun Zhang,
Huaijin Zhang
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ABSTRACT: We report a nanosecond singly resonant intracavity optical parametric oscillator (OPO) emitting at 1535 nm. This OPO is based on a type II non-critically phase-matched KTiOAsO4 (KTA) crystal. A diode-side-pumped acousto-optically Q-switched Nd : YAG laser is used as the pumping source. With a laser diode power of 96.3 W and a pulse repetition rate of 10 kHz, we obtain a signal power of 2.54 W, corresponding to an optical-to-optical conversion efficiency of 2.6%. This is the highest efficiency reported for intracavity KTA OPOs with diode-side-pumping configurations. The pulse width is 5.01 ns and the peak power is 50.7 kW. The stability of the signal power is measured to be better than 3% during 2 h operation.
Journal of Physics D Applied Physics 06/2008; 41(13):135112. · 2.54 Impact Factor
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ABSTRACT: A highly efficient diode-pumped actively Q-switched intracavity Raman laser with SrWO(4) as the Raman-active medium is presented. As high as 23.8% diode-to-Stokes optical conversion efficiency is obtained with an incident pump power of 7.17 W and a pulse repetition rate of 15 kHz.
Optics Letters 05/2008; 33(7):705-7. · 3.40 Impact Factor
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ABSTRACT: By using an a-cut GdVO4 crystal as the Raman-active medium, a KTP crystal as the frequency-doubling medium, and an Nd : YAG crystal as the gain medium, a small scale (10 cm) and efficient diode-pumped intracavity frequency-doubled Raman laser is obtained. When the pulse repetition frequency is 15 kHz and the incident pump power is 10.1 W, the obtained average laser power at 58 nm is 763 mW. The pulse width is 3.8 ns and the corresponding peak power is 13.4 kW.
Journal of Physics D Applied Physics 02/2008; 41(5):055104. · 2.54 Impact Factor
