Browsing by Author "Kung, AH"

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Broad multiwavelength second-harmonic generation from two-dimensional chi((2)) nonlinear photonic crystals of tetragonal lattice structure
(2004-09-01)
Peng, LH
;
Hsu, CC
;
Kung, AH
;
交大名義發表
;
National Chiao Tung University
We investigate the effects of lattice spacing and domain-filling ratio on the wavelength dependence in second-harmonic generation (SHG) from two-dimensional chi((2)) nonlinear photonic crystals (2-D NPC) on lithium niobate. Spectral coverage of 150 and 200 nm around 1.5 and 1.9 mum in quasi-phase-matched (QPM) SHG is obtained by angular rotation of the NPC with a lattice periodicity of 20 x 20 and 29.5 x 29.5 mum(2), respectively. The SHG signals are shown to have off-axial propagation directions determined by the incident wavelength and the QPM vector. The intensity of the high-order reciprocal-lattice-vector (G(mn))-assisted SHG signal is shown to depend on the domain-filling ratio. These observations are attributed to the unique dispersion of G(mn) together with the nonzero chi((2)) (G(mn)) nonlinearity in the 2-D QPM-NPC having a tetragonal lattice structure.
Efficient all-solid-state deep ultraviolet laser source
(2001)
Chang, LB
;
Wang, SC
;
Kung, AH
;
光電工程學系
;
Department of Photonics
Stable watt level operation in the UV is achieved from a laser-diode-pumped Nd:YAG laser by fourth-harmonic generation in an external cavity. Over 1.4 watt at 266 nm in a TEMoo beam was obtained, and long term stability better than 99% (>1 hr) . 284mW at 213 nm were also obtained from 830 mW at 266 nm.
Efficient compact watt-level deep-ultraviolet laser generated from a multi-kHz Q-switched diode-pumped solid-state laser system
(2002-08-15)
Chang, LB
;
Wang, SC
;
Kung, AH
;
光電工程學系
;
Department of Photonics
Stable high-power operation in the deep ultraviolet is achieved from a multi-kHz diode-pumped multi-longitudinal-mode Q-switched Nd:YAG laser by fourth harmonic generation in an external resonant cavity and by fifth harmonic generation using sum-frequency mixing of the fourth harmonic and the residual fundamental in a beta-BBO crystal. Over 2.1 W of 266 nm radiation and 540 mW of 213 nm radiation were generated from a fundamental power of 7 W of 1064 nm light at 5 kHz. The overall conversion efficiency from IR to deep ultraviolet at 213 nm is larger than 7.5%. (C) 2002 Elsevier Science B.V. All rights reserved.
Efficient periodically poled stoichiometric lithium tantalate optical parametric oscillator for the visible to near-infrared region
(2005-09-15)
Tu, SY
;
Kung, AH
;
Gao, ZD
;
Zhu, SN
;
光電工程學系
A compact, efficient optical parametric oscillator (OPO) for the visible to near-infrared region based on periodically poled stoichiometric lithium tantalate pumped by a frequency-doubled multikilohertz Q-switched Nd:YAG laser is demonstrated. Up to 61% photon conversion with a 71% slope efficiency for photon conversion from 532 nm to the signal radiation was measured. We observed that the efficient conversion diminished the potential for photorefractive damage induced by the 532 am radiation in the crystal and made sustained operation of the OPO device possible. (c) 2005 Optical Society of America.
Multipass acoustically open photoacoustic detector for trace gas measurements
(2006-04-10)
Miklos, A
;
Pei, SC
;
Kung, AH
;
光電工程學系
;
Department of Photonics
What we believe to be a novel multipass, acoustically open photoacoustic detector designed for fast-response, high-sensitivity detection of trace gases and pollutants in the atmosphere is demonstrated. The acoustic pulses generated by the absorption of the light pulses of a tunable optical parametric oscillator by target molecules are detected by an ultrasonic sensor at 40 kHz. The photoacoustic signal is enhanced by an optical multipass arrangement and by concentration of the acoustic energy to the surface of the ultrasonic sensor. The detection sensitivity, estimated from CO2 measurements around a 2 mu m wavelength, is similar to 3.3 x 10(-9) W cm(-1). (c) 2006 Optical Society of America.
Numerical analysis of fifth-harmonic conversion of low-power pulsed Nd : YAG laser with resonance of second harmonic
(2003-07-01)
Chang, LB
;
Wang, SC
;
Kung, AH
;
光電工程學系
;
Department of Photonics
A model for the fifth-harmonic generation of pulsed IR lasers involving an external ring cavity resonating at the second harmonic has been developed. Numerical analysis is performed to show the relative effects of the pulse delay, input polarization, and orientation of the nonlinear crystals on the fifth harmonic power. The results are validated by published experimental results. The model is used to analyze and obtain the optimal combination of nonlinear optical crystals for the fifth-harmonic generation. Our calculation shows that the combination of LiB3O5 (LBO), CsLiB6O10 (CLBO), and CLBO crystals for the second-harmonic, fourth-harmonic, and fifth-harmonic generation steps respectively gives an approximate conversion of 30% from the fundamental to the fifth harmonic power, resulting in 2W at 213 nm for an input of 7W at 1064nm.
Progressive stabilization of zwitterionic structures in [H(Ser)(2-8)](+) studied by infrared photodissociation spectroscopy
(2006)
Kong, XL
;
Tsai, IA
;
Sabu, S
;
Han, CC
;
Lee, YT
Tunable deep-ultraviolet source generated by scattering off adiabatically prepared Raman coherence in hydrogen gas
(2005-10-01)
Chen, WJ
;
Kung, AH
;
光電工程學系
;
Department of Photonics
We demonstrate a tunable deep-ultraviolet coherent source generated by the beating of a tunable UV laser and strongly driven vibrational Raman coherence in hydrogen. The total energy conversion efficiency reaches a maximum of 50% at the phase side of the Raman coherence. The generated spectrum of Raman sidebands tunes with the input and extends from 435 to 146 nm for an input at 282 nm. (c) 2005 Optical Society of America.