Browsing by Author "Huang, Y. J."

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Compact efficient multi-GHz Kerr-lens mode-locked diode-pumped Nd:YVO(4) laser
(2008-12-08)
Liang, H. C.
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Chen, Ross C. C.
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Huang, Y. J.
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Su, K. W.
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Chen, Y. F.
We demonstrate the compact efficient multi-GHz Kerr-lens mode locking in a diode-pumped Nd:YVO(4) laser with a simple linear cavity without the need of any additional components. Experimental results reveal that the laser system can be characterized in stable single-pulse and multiple-pulse mode-locked operations. With a pump power of 2.5 W, the compact laser cavity produces average output powers greater than 0.8 W with a pulse width less than 10 ps in the range of 2-6 GHz. (C) 2008 Optical Society of America
Compact high-pulse-energy passively Q-switched Nd:YLF laser with an ultra-low-magnification unstable resonator: application for efficient optical parametric oscillator
(2013-01-28)
Cho, C. Y.
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Huang, Y. P.
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Huang, Y. J.
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Chen, Y. C.
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Su, K. W.
We exploit an ultra-low-magnification unstable resonator to develop a high-pulse-energy side-pumped passively Q-switched Nd:YLF/Cr4+:YAG laser with improving beam quality. A wedged laser crystal is employed in the cavity to control the emissions at 1047 nm and 1053 nm independently through the cavity alignment. The pulse energies at 1047 nm and 1053 nm are found to be 19 mJ and 23 mJ, respectively. The peak powers for both wavelengths are higher than 2 MW. Furthermore, the developed Nd:YLF lasers are employed to pump a monolithic optical parametric oscillator for confirming the applicability in nonlinear wavelength conversions. (C) 2013 Optical Society of America
Comparative study between conventional and diffusion-bonded Nd-doped vanadate crystals in the passively mode-locked operation
(2010-04-26)
Huang, Y. J.
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Huang, Y. P.
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Liang, H. C.
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Su, K. W.
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Chen, Y. F.
We design a reliable linear three-element cavity to make a comparative study between the conventional and diffusion-bonded Nd:GdVO(4) crystals in the passively mode-locked operation. Experimental investigations reveal that the mode-locked pulse width obtained with the diffusion-bonded crystal is considerably broader than that obtained with the conventional crystal, even though the diffusion-bonded crystal can significantly reduce the thermal effects. The pulse broadening is experimentally verified to come from the length of the undoped part that brings in a reduction of the spatial-hole-burning (SHB) effect. (C) 2010 Optical Society of America
Comparative study of intracavity KTP-based Raman generation between Nd:YAP and Nd:YAG lasers operating on the F-4(3/2) -> I-4(13/2) transition
(2015-04-20)
Huang, Y. J.
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Chen, Y. F.
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Chen, W. D.
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Zhang, G.
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電子物理學系
Extending the spectral wavelengths of the diode-pumped Nd-doped lasers at 1.3 mu m with the KTP crystal in the intracavity Raman configuration is reported for the first time to the best of our knowledge. A systematic comparison is performed to show that a better optical conversion efficiency for the Nd:YAP/KTP Raman laser could be achieved thanks to the higher peak power and linearly polarized radiation at 1341 nm, whereas up to four Stokes emission lines are generated from the Nd: YAG/KTP Raman laser as a result of the fundamental dual-color operation at 1319 and 1338 nm. The maximum Stokes output power of the developed Nd: YAP/KTP Raman laser reaches 1.04 W under an incident pump power of 16 W and a pulse repetition rate of 10 kHz, corresponding to the diodeto-Stokes conversion efficiency as high as 6.5%. The largest pulse energy and highest peak power are evaluated to be up to 104 mu J and 34.7 kW, respectively. (C) 2015 Optical Society of America
Controlling number of lasing modes for designing short-cavity self-mode-locked Nd-doped vanadate lasers
(2011-06-01)
Chen, Y. F.
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Huang, Y. J.
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Chiang, P. Y.
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Lin, Y. C.
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Liang, H. C.
A short-cavity Nd:YVO(4) laser is employed to confirm that a spontaneous mode locking (SML) typically occurs without employing an extra nonlinearity. We further experimentally demonstrate that reducing the number of longitudinal lasing modes can diminish the phase fluctuation and effectively improve the SML pulse stability. Considering the spatial hole-burning (SHB) effect, an analytical expression is derived to accurately estimate the number of longitudinal lasing modes for a practical design guideline.
Diode-Pumped Nd:YAP Intracavity Optical Parametric Oscillator Emitting at 1603 nm: Influence of Energy-Transfer Upconversion
(2016-06-01)
Cho, H. H.
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Huang, Y. J.
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Chen, W. D.
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Zhang, G.
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Chen, Y. F.
A diode-end-pumped actively Q-switched Nd:YAP laser at 1080 nm is originally designed to intracavity pump a Potassium Titanyl Phosphate KTiOPO4 (KTP)-based optical parametric oscillator for obtaining the signal wavelength at 1603 nm. Under an absorbed pump power value of 11 W, the maximum average output power at the eye-safe radiation is efficiently generated to be 1.11 W at a pulse repetition rate of 10 kHz. At a pulse repetition rate of 5 kHz, the shortest pulse duration, the largest pulse energy, and the highest peak power are found to be 2.4 ns, 190 mu J, and 67.3 kW, respectively. In addition, the influence of energy-transfer upconversion effect on the capability of power scaling of the developed Nd: YAP fundamental laser is experimentally investigated and theoretically analyzed.
Dual-wavelength eye-safe Nd:YAP Raman laser
(2015-08-01)
Huang, Y. J.
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Chen, Y. F.
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Chen, W. D.
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Zhang, G.
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電子物理學系
We report on a diode-pumped, Q-switched intracavity-Raman-shifted Nd-doped yttrium-aluminum-perovskite (Nd:YAP) laser using potassium titanyl phosphate (KTP) or potassium titanyl arsenate (KTA) nonlinear crystals to produce eye-safe radiation. In both cases, we obtained simultaneous laser emission at two wavelengths corresponding to distinct Raman gain peaks and different Stokes orders for the nonlinear crystal used. From the Nd:YAP/KTP laser source, we obtained 3 ns pulses of combined 21 kW peak power at 1478 and 1503 nm. From the Nd:YAP/KTA laser source, we obtained up to 220 mW total average output power, equally split between 1474 and 1480 nm emission lines. (C) 2015 Optical Society of America
Dual-Wavelength Intracavity OPO With a Diffusion-Bonded Nd: YVO4/Nd:GdVO4 Crystal
(2016-05-15)
Huang, Y. J.
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Cho, H. H.
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Su, K. W.
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Chen, Y. F.
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電子物理學系
A novel diffusion-bonded Nd: YVO4/Nd: GdVO4 crystal is originally designed for developing a high-power diode-end-pumped actively Q-switched laser emitting synchronous pulses at 1063.17 and 1064.41 nm. The maximum total average output power of 6.4 W is efficiently generated under an incident pump power of 21.6 W, whereas the shortest pulse duration, largest pulse energy, and highest peak power are achieved to be 9 ns, 285 mu J, and 31.7 kW, respectively. By constructing an intracavity optical parametric oscillator with a monolithic cavity, the emission wavelengths are further extended to the eye-safe region with the maximum total average output power of 2.3 W at 1570.36 and 1572.55 nm, corresponding to the optical conversion efficiency of up to 10.6%.
Effect of spatial hole burning on a dual-wavelength mode-locked laser based on compactly combined dual gain media
(2014-12-01)
Huang, Y. J.
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Tzeng, Y. S.
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Cho, H. H.
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Chen, Y. F.
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電子物理學系
The effect of spatial hole burning (SHB) on dual-wavelength self-mode-locked lasers based on physically combined Nd:YVO4/Nd:LuVO4 and Nd:YVO4/Nd:KGW composite active medium is comparatively investigated. The length of the first Nd:YVO4 crystal is optimized to realize a highly compact and efficient TEM00-mode pico-second laser at 1.06 mu m with optical conversion efficiency greater than 20%. When the SHB effect is enhanced by decreasing the separation between the input end mirror and the composite gain medium, it is experimentally found that not only the pulse duration monotonically decreases, but also the temporal behavior gradually displays a narrow-peak-on-a-pedestal shape for the Nd:YVO4/Nd:LuVO4 scheme, while the multipulse operation can be obtained for the Nd:YVO4/Nd: KGW configuration. These phenomena are further explored by numerically simulating mode-locked pulses from the experimentally measured optical spectra. (C) 2014 Chinese Laser Press
Efficient dual-wavelength diode-end-pumped laser with a diffusion-bonded Nd:YVO4/Nd:GdVO4 crystal
(2015-10-01)
Huang, Y. J.
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Cho, H. H.
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Tzeng, Y. S.
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Liang, H. C.
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Su, K. W.
A new type of diffusion-bonded Nd:YVO4/Nd:GdVO4 hetero-composite crystal is originally designed and applied to diode-end-pumped laser for achieving an efficient dual-comb picosecond operation with self-mode locking for the first time. As high as 1.1 W of the total average output power at 1063.18 and 1064.37 nm is generated under an incident pump power of 5.1 W. The corresponding mode-locked pulse width is 42 ps at a pulse repetition rate of 3.82 GHz. Through the optical beating between two carrier frequencies of each spectral component, a train of ultrashort pulses with sub-terahertz repetition rate is further generated with the effective duration of down to 1.6 ps. (C) 2015 Optical Society of America.
Efficient high-energy passively Q-switched Nd:YLF/Cr4+: YAG UV laser at 351 nm with pulsed pumping in a nearly hemispherical cavity
(2013-02-15)
Huang, Y. J.
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Tang, C. Y.
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Tzeng, Y. S.
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Su, K. W.
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Chen, Y. F.
We originally utilize a nearly hemispherical cavity to accomplish the energy scale-up for a high-repetition-rate nanosecond pulsed pumped Nd:YLF laser passively Q-switched by the Cr4+:YAG saturable absorber. This compact laser is able to efficiently generate pulse energy as large as 1.38 mJ and pulse width as short as 5 ns under a pulse repetition rate of 100 Hz. Further employing the developed Nd: YLF laser to perform extracavity harmonic generations, the maximum pulse energies of 490 mu J at 527 nm and 360 mu J at 351 nm are achieved with the shortest pulse duration of 4 ns. (C) 2013 Optical Society of America
Efficient high-energy pulse generation from a diode-side-pumped passively Q-switched Nd:YAG laser and application for optical parametric oscillator
(2014-09-01)
Huang, Y. P.
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Huang, Y. J.
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Cho, C. Y.
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電子物理學系
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Department of Electrophysics
We employ a convex-concave resonator to develop a high-pulse-energy diode-side-pumped passively Q-switched Nd:YAG laser with high extraction efficiency. At a diode pump energy of 227 mJ, the output laser pulse reaches 30 mJ with a pulse width of 6 ns at a repetition rate of 20 Hz. The optical-to-optical conversion efficiency is up to 13.2%. Based on the developed Nd:YAG laser oscillator, we further employ a monolithic KTP crystal to perform the optical parametric oscillator (OPO). With the 1064 nm input energy of 30 mJ, the OPO energy at 1573 nm is found to be 13.3 mJ, corresponding to an OPO conversion efficiency as high as 44.3%.
Efficient high-energy pulse generation from a diode-side-pumped passively Q-switched Nd:YAG laser and application for optical parametric oscillator
(2014-09-01)
Huang, Y. P.
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Huang, Y. J.
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Cho, C. Y.
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電子物理學系
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Department of Electrophysics
We employ a convex-concave resonator to develop a high-pulse-energy diode-side-pumped passively Q-switched Nd:YAG laser with high extraction efficiency. At a diode pump energy of 227 mJ, the output laser pulse reaches 30 mJ with a pulse width of 6 ns at a repetition rate of 20 Hz. The optical-to-optical conversion efficiency is up to 13.2%. Based on the developed Nd:YAG laser oscillator, we further employ a monolithic KTP crystal to perform the optical parametric oscillator (OPO). With the 1064 nm input energy of 30 mJ, the OPO energy at 1573 nm is found to be 13.3 mJ, corresponding to an OPO conversion efficiency as high as 44.3%.
Efficient high-power terahertz beating in a dual-wavelength synchronously mode-locked laser with dual gain media
(2014-03-15)
Huang, Y. J.
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Tzeng, Y. S.
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Tang, C. Y.
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Chiang, S. Y.
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Liang, H. C.
We originally present a novel tactic to accomplish a compact efficient dual-wavelength synchronously mode-locked laser by physically combining the Nd:YVO4 crystal to the Nd: GdVO4 crystal as a composite gain medium. With the developed method, the total output power at 1.06 mu m could be effectually produced to reach 1.3 W under the optimally balanced two-color intensities. The corresponding mode-locked pulse width and repetition rate are measured to be 47 ps and 2.86 GHz, respectively. Through the optical beating between two carrier frequencies of dual-color synchronous pulses, a train of 0.32 THz ultrashort pulses is further generated with the effective duration of down to 1.6 ps. (C) 2014 Optical Society of America
Efficient high-power UV laser generated by an optimized flat-flat actively Q-switched laser with extra-cavity harmonic generations
(2012-01-01)
Huang, Y. J.
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Chiang, P. Y.
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Liang, H. C.
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Su, K. W.
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Chen, Y. F.
We investigate the parasitic lasing effect in the high-power actively Q-switched laser with a flat-flat resonator. The parasitic lasing effect in the low-Q stage is found to lead to long tails in the output pulses, corresponding to the peak-power reduction. We experimentally determine the shortest cavity length without the parasitic lasing effect to optimize the performance of the high-power actively Q-switched laser with a flat-flat cavity. We further use the optimized fundamental laser to generate green and UV lasers by extra-cavity harmonic generations. At a pump power of 44 W, the output powers at 355 nm and 532 nm as high as 6.65 W and 8.38 W are obtained at a pulse repetition rate of 40 kHz. (C) 2011 Elsevier B.V. All rights reserved.
Efficient high-pulse-energy eye-safe laser generated by an intracavity Nd:YLF/KTP optical parametric oscillator: role of thermally induced polarization switching
(2012)
Huang, Y. J.
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Tang, C. Y.
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Huang, Y. P.
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Cho, C. Y.
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Su, K. W.
A high-pulse-energy eye-safe laser at 1552 nm is effectually generated by an intracavity Nd:YLF/KTP optical parametric oscillator (OPO) with the help of the thermally induced polarization switching. The polarization characteristics of the c-cut Nd:YLF laser at 1053 nm in the continuous-wave (CW) and Q-switched operation are comprehensively investigated. We experimentally verify the thermally induced birefringence can lead to a polarization switching between the mutually orthogonal components of the fundamental pulses. Consequently, an efficient intracavity nonlinear frequency conversion can be achieved in an optically isotropic laser crystal without any additional polarization control. With this finding, the pulse energy and peak power of the compact Nd: YLF/KTP eye-safe laser under an incident pump power of 12.7 W and a pulse repetition rate of 5 kHz are up to 306 mu J and 4 kW, respectively.
Efficient passively Q-switched Nd:YLF TEM00-mode laser at 1053 nm: selection of polarization with birefringence
(2012-08-01)
Huang, Y. J.
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Tang, C. Y.
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Lee, W. L.
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Huang, Y. P.
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Huang, S. C.
"The natural birefringence of the Nd:YLF crystal is utilized to achieve a reliable TEM00-mode linearly polarized laser at 1053 nm in a compact concave-plano resonator. The efficient selection of the polarization relies on the combined effect of the difference in diffraction angle for sigma- and pi-polarization of a wedged laser crystal and the alignment sensitivity of an optical resonator. We further employ a Cr4+:YAG saturable absorber to perform the passively Q-switched operation. At an incident pump power of 12 W, the maximum average output power is up to 2.3 W with a pulse repetition rate of 8 kHz and a pulse width of 9 ns. The pulse energy and peak power are found to be 288 mu J and 32 kW, respectively."
Exploring the origin of the directional emission from a microcavity with a large-aperture surface-emitting laser
(2009-06-15)
Chen, Ross C. C.
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Yu, Y. T.
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Huang, Y. J.
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Chen, C. C.
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Chen, Y. F.
The origin of the direction emission from a microcavity is investigated with a large-aperture surface-emitting laser with an equilateral-triangular shape. Experimental results reveal that a wide-spread eigen-mode and a localized superscar mode can display quite similar far-field directional emissions. This experimental finding is theoretically confirmed with the quantum-billiard wave function and the approximation of the paraxial propagation. (C) 2009 Optical Society of America
Generation of multiple spectral bands in a diode-pumped self-mode-locked Nd:YAP laser
(2016-02)
Huang, Y. J.
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Tzeng, Y. S.
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Cho, H. H.
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Chen, Y. F.
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Chen, W. D.
A single- and multispectral-band diode end-pumped self-mode-locked Nd:YAP laser is originally demonstrated with an intracavity etalon to properly control the gain-to-loss ratios among the intermanifold lines on the F-4(3/2) -> I-4(11/2) transition level. With a pulse repetition rate of 5.07 (3Hz, the shortest pulse durations under the single-spectral-hand operation are achieved to be 11.1 ps at 1073 nm, 10.9 ps at 1080 nm, and 15.1 ps at 1084 nm, respectively. Moreover, the temporal overlapping of the multispectral-band pulses is experimentally found to lead to the generation of an intensity fringe pattern in the autocorrelation trace with the optical-beat frequency reaching several terahertz. A simple mathematical model is developed to elucidate the formation of a train of optical-beat pulses.
High-power 10-GHz self-mode-locked Nd:LuVO(4) laser
(2011-10-01)
Huang, Y. J.
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Liang, H. C.
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Chen, Y. F.
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Zhang, H. J.
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Wang, J. Y.
We report on a high-power diode-end-pumped self-mode-locked Nd:LuVO(4) laser with the pulse repetition rate up to 9.52 GHz for the first time. The large third-order nonlinearity of the Nd:LuVO(4) crystal is exploited to efficiently achieve a fairly stable self-mode-locked operation without any additional components. The detailed characteristics of the compact efficient self-mode-locked laser are experimentally investigated and theoretically analyzed. With the incident pump power of 2.6 W, the average output power up to 0.54 W is generated with the pulse width of 7.9 ps at the pulse repetition rate of 9.52 GHz.