Browsing by Author "Su, K. W."

Now showing 1 - 20 of 91

AlGaInAs intracavity selective absorber for an efficient high-power Nd : YAG laser operation at 1.44 mu m
(2008-07-01)
Huang, Y. P.
;
Chang, Y. T.
;
Su, K. W.
;
Chen, Y. F.
;
Huang, K. F.
We develop an AlGaInAs material as a promising intracavity selective absorber for an efficient high-power Nd:YAG laser at 1.44 mu m. With the ISA to suppress operation at 1.06 mu m, the output coupler at 1.44 mu m can be straightforwardly designed and optimized. At a pump power of 16 W an output power of 2.5 W at 1.44 mu m, with a slope efficiency of 23%, was achieved. (C) 2008 Optical Society of America.
AlGaInAs quantum-well 1.3-mu m laser by a diode-pumped actively Q-switched Nd : GdVO4 laser - art. no. 68712K
(2008)
Huang, S. C.
;
Su, K. W.
;
Li, A.
;
Liu, S. C.
;
Chen, Y. F.
We report a high-peak-power AlGaInAs 1.36-mu m vertical-external-cavity surface-emitting laser (VECSEL) optically pumped by a diode-pumped actively Q-switched Nd:GdVO4 1.06-mu m laser under room-temperature operation. The gain medium is an AlGaInAs quantum wells (QWs)/barrier structure grown on a Fe-doped InP substrate by metalorganic chemical-vapor deposition. With an average pump power of 1.9 W, an average output power of 340 mW was obtained at a pulse repetition rate of 40 kHz, corresponding to an optical-to-optical conversion efficiency of 18.76%. With a peak pump power of 7.9 kW, the highest peak output power was 1.3 kW at a pulse repetition rate of 10 kHz.
AlGaInAs quantum-well as a saturable absorber in a diode-pumped passively Q-switched solid-state laser
(2007-06-01)
Huang, S. C.
;
Liu, S. C.
;
Li, A.
;
Su, K. W.
;
Chen, Y. F.
We demonstrate what is believed to be the first use of AlGaInAs quantum wells (QWs) as a saturable absorber in the Q switching of a high-power diode-pumped Nd-doped 1.06 mu m laser. 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 power of 13.5 W, an average output power of 3.5 W with a Q-switched pulse width of 0.9 ns at a pulse repetition rate of 110 kHz was obtained. (c) 2007 Optical Society of America.
AlGaInAs/InP eye-safe laser pumped by a Q-switched Nd:GdVO(4) laser
(2009-03-01)
Huang, S. C.
;
Chang, H. L.
;
Su, K. W.
;
Li, A.
;
Liu, S. C.
An AlGaInAs quantum-well structure grown on a Fe-doped InP transparent substrate is developed to be a gain medium in a high-peak-power nanosecond laser at 1570 nm. Using an actively Q-witched 1064 nm laser to pump the gain chip, an average output power of 135 mW is generated at a pulse repetition rate of 30 kHz and an average pump power of 1.25 W. At a pulse repetition rate of 20 kHz, the peak output power is up to 290 W at a peak pump power of 2.3 kW.
AlGaInAs/InP eye-safe laser pumped by a Q-switched Nd:GdVO4 laser
(2009-03-01)
Huang, S. C.
;
Chang, H. L.
;
Su, K. W.
;
Li, A.
;
Liu, S. C.
An AlGaInAs quantum-well structure grown on a Fe-doped InP transparent substrate is developed to be a gain medium in a high-peak-power nanosecond laser at 1570 nm. Using an actively Q-witched 1064 nm laser to pump the gain chip, an average output power of 135 mW is generated at a pulse repetition rate of 30 kHz and an average pump power of 1.25 W. At a pulse repetition rate of 20 kHz, the peak output power is up to 290 W at a peak pump power of 2.3 kW.
Analytical model for optimizing the parameters of an external passive Q-switch in a fiber laser
(2008-05-01)
Huang, J. Y.
;
Liang, H. C.
;
Su, K. W.
;
Chen, Y. F.
;
電子物理學系
An analytical model is developed for optimizing two key parameters of an external passive Q-switch in a fiber laser from the criterion of the minimum average mode area inside the saturable absorber. One parameter is the optimum focal position that is analytically derived to be a function of the thickness and initial transmission of the saturable absorber. The other parameter is the optimum magnification of the reimaging optics that is analytically derived to be in terms of the numerical aperture and core radius of the laser fiber as well as the thickness and initial transmission of the saturable absorber. To demonstrate the utilization of the present model, an experiment on the subject of the passively Q-switched fiber laser is performed and optimized. (C) 2008 Optical Society of America.
Analytical model for the design of external-cavity passively Q-switched fiber lasers
(2008)
Huang, J. Y.
;
Liang, H. C.
;
Su, K. W.
;
Chen, Y. F.
;
電子物理學系
An analytical model has been developed to minimize the effective mode area in a saturable absorber for an external-cavity passively Q-switched fiber laser. Under the condition of minimum effective mode size inside the saturable absorber, the analytical expressions for two key parameters of an optimum system have been derived. One parameter is the optimum focal position that is analytically derived to be a function of the thickness and initial transmission of the saturable absorber. The other parameter is the optimum magnification of the re-imaging optics that is analytically derived to be in terms of the numerical aperture and core radius of the laser fiber as well as the thickness and initial transmission of the saturable absorber. The present model provides a straightforward procedure to adopt a focusing system for the output performance. A diode-pumped ytterbium-doped fiber lasers with a Cr:YAG crystal as a saturable absorber is considered to illustrate the utility of the present model.
Analytical representation for structured light generated by astigmatic transformation of Hermite-Gaussian beams
(2018-01-01)
Hsieh, Y. H.
;
Tuan, P. H.
;
Tung, J. C.
;
Liang, H. C.
;
Su, K. W.
Theoretical wave functions are analytically derived to formulate the propagation evolution of the Hermite-Gaussian (HG) beams transformed by single lens astigmatic mode converter with arbitrary angle. The derived wave functions are associated with the combination of the rotation transform and the antisymmetric fractional Fourier transform. The derived formula are validated by the mode conversions of high-order HG beams generated by an off-axis diode-pumped solid-state laser. In addition to validation, the creation and evolution of vortex structures in the transformed HG beams are numerically manifested. The present theoretical model can be applied not only to characterize the evolution of the transformed beams but to design the optical vortex beams with various forms.
Astigmatism inducing the degenerate effect in nearly hemispherical cavities: Generation of three-dimensional structured light
(2017-01-01)
Tung, J. C.
;
Hsieh, Y. H.
;
Liang, H. C.
;
Su, K. W.
;
Huang, K. F.
We originally perform an analytical form to explore the influence of the astigmatism on the degenerate effect in nearly hemispherical cavities. The frequency spectrum near hemispherical cavities clearly reveals that not only the difference of cavity lengths between each degeneracies but also frequency gaps have significant difference from non-hemispherical cavities. We further thoroughly demonstrate the laser experiment under the condition of nearly hemispherical cavities to confirm the theoretical exploration that the transverse topology of three-dimensional (3D) structured light in the degenerate cavities is well localized on the Lissajous curves.
Broad expansion of optical frequency combs by self-Raman scattering in coupled-cavity self-mode-locked monolithic lasers
(2017-04-03)
Chang, M. T.
;
Huang, T. L.
;
Liang, H. C.
;
Su, K. W.
;
Chen, Y. F.
Broad expansion of optical frequency comb (OFC) by the self-Raman scattering is numerically analyzed and experimentally accomplished in a coupled-cavity self-mode-locked (SML) monolithic Yb:KGW laser. The gain medium is coated to achieve the monolithic SML operation and a partially reflective mirror is further exploited to form the coupled cavity and to multiply the repetition rate up to 128.9 GHz. With a coupled reflectivity of 95%, it is experimentally found that not only the first-order but also second-order stimulated Raman scattering (SRS) can be efficiently generated. The mode-locked OFC can be consequently expanded to reach approximately 8.4 THz, leading the pulse width to be as narrow as 53 fs. At the pump power of 8.7 W, the total output power for the fundamental and the first-and second-Stokes waves can be maintained at 1.6 W. The present exploration provides a promising way to generate the ultrahigh-repetition-rate broadband OFC via the simultaneous SML and SRS processes. (C) 2017 Optical Society of America
Compact efficient eye-safe intracavity optical parametric oscillator with a shared cavity configuration
(2007-06-10)
Chen, Y. F.
;
Su, K. W.
;
Chang, Y. T.
;
Yen, W. C.
;
電子物理學系
We present a compact efficient eye-safe intracavity optical parametric oscillator pumped by a passively Q-switched Nd:YAG laser in a shared cavity configuration. A signal pulse of 3.3 mJ energy at a 1573 nm wavelength with a peak power of 150 kW was achieved. The effective conversion efficiency with respective to the optimized 1064 nm Q-switched pulse energy was as high as 51%. (C) 2007 Optical Society of America.
Compact efficient multi-GHz Kerr-lens mode-locked diode-pumped Nd:YVO(4) laser
(2008-12-08)
Liang, H. C.
;
Chen, Ross C. C.
;
Huang, Y. J.
;
Su, K. W.
;
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 efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO(4) crystal as a self-Raman medium
(2009-03-16)
Chang, Y. T.
;
Su, K. W.
;
Chang, H. L.
;
Chen, Y. F.
;
電子物理學系
We report on an efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO(4) crystal as a self-Raman gain medium. A diffusion-bonded crystal not only reduces the thermal effects but also increase the interaction length for the stimulated Raman scattering. With an input pump power of 17.2 W, average power of 2.23 W at the first-Stokes wavelength of 1525 nm is generated at a pulse repetition rate of 40 kHz, corresponding to a conversion efficiency of 13%. (C) 2009 Optical Society of America
Compact efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO4 crystal as a self-Raman medium
(2009-03-16)
Chang, Y. T.
;
Su, K. W.
;
Chang, H. L.
;
Chen, Y. F.
;
電子物理學系
We report on an efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO4 crystal as a self-Raman gain medium. A diffusion-bonded crystal not only reduces the thermal effects but also increase the interaction length for the stimulated Raman scattering. With an input pump power of 17.2 W, average power of 2.23 W at the first-Stokes wavelength of 1525 nm is generated at a pulse repetition rate of 40 kHz, corresponding to a conversion efficiency of 13%. (C) 2009 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.
;
Huang, Y. P.
;
Huang, Y. J.
;
Chen, Y. C.
;
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 studies for Cr(4+):YAG crystal and AlGaInAs semiconductor used as a saturable absorber in Q-switched Yb-doped fiber lasers
(2009-11-09)
Huang, J. Y.
;
Zhuang, W. Z.
;
Huang, W. C.
;
Su, K. W.
;
Hu, C.
We demonstrate comparative studies for Cr(4+):YAG crystal and AlGaInAs quantum-well (QW) used as a saturable absorbers in passively Q-switched Yb-doped fiber lasers. Both saturable absorbers were designed to be possessed of nearly the same initial transmission. Under a pump power of 24 W, the average output powers were up to 14.4 W and 13.8 W obtained with the AlGaInAs QWs and with the Cr(4+):YAG crystal, respectively. The maximum pulse energies obtained with the Cr(4+):YAG crystal and with the AlGaInAs QWs were found to be 0.35 mJ and 0.45 mJ, respectively. (C) 2009 Optical Society of America
Comparative studies for Cr4+:YAG crystal and AlGaInAs semiconductor used as a saturable absorber in Q-switched Yb-doped fiber lasers
(2009-11-09)
Huang, J. Y.
;
Zhuang, W. Z.
;
Huang, W. C.
;
Su, K. W.
;
Hu, C.
We demonstrate comparative studies for Cr4+:YAG crystal and AlGaInAs quantum-well (QW) used as a saturable absorbers in passively Q-switched Yb-doped fiber lasers. Both saturable absorbers were designed to be possessed of nearly the same initial transmission. Under a pump power of 24 W, the average output powers were up to 14.4 W and 13.8 W obtained with the AlGaInAs QWs and with the Cr4+:YAG crystal, respectively. The maximum pulse energies obtained with the Cr4+:YAG crystal and with the AlGaInAs QWs were found to be 0.35 mJ and 0.45 mJ, respectively. (C) 2009 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.
;
Huang, Y. P.
;
Liang, H. C.
;
Su, K. W.
;
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
Comparison of thermal lensing effects between single-end and double-end diffusion-bonded Nd:YVO(4) crystals for (4)F(3/2)->(4)I(11/2) and (4)F(3/2)->(4)I(13/2) transitions
(2008-12-08)
Chang, Y. T.
;
Huang, Y. P.
;
Su, K. W.
;
Chen, Y. F.
;
電子物理學系
The effective focal lengths of thermal lens in diode-end-pumped continuous-wave Nd:YVO(4) lasers for the (4)F(3/2)->(4)I(11/2) and (4)F(3/2)->(4)I(13/2) transitions were determined. The experimental results revealed that the thermal lensing effect for the (4)F(3/2)->(4)I(11/2) transition can be sufficiently improved by employing a single-end diffusion-bonded Nd: YVO4 crystal replacing a conventional Nd: YVO4 crystal. However, using a double-end diffusion-bonded Nd: YVO4 crystal was a great improvement over a single-end diffusion-bonded Nd: YVO4 crystal for the (4)F(3/2)->(4)I(13/2) transition with stronger thermal lensing effect. (C) 2008 Optical Society of America
Diode-pumped multi-frequency Q-switched laser with intracavity cascade Raman emission
(2008-05-26)
Chang, Y. T.
;
Huang, Y. P.
;
Su, K. W.
;
Chen, Y. F.
;
電子物理學系
A diode-pumped actively Q-switched mixed Nd:Y0.3Gd0.7VO4 laser with an intracavity KTP crystal is developed to produce cascade SRS emission up to the fourth order. With an incident pump power of 14 W and a repetition rate of 50 kHz, the average output powers at the first, second, third and fourth Stokes modes are approximately 0.05 W, 0.61 W, 0.25 W, and 0.11 W, respectively. The maximum peak power is greater than 2 kW. (C) 2008 Optical Society of America.