Browsing by Author "Cho, Sheng-Lung"

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High saturation output power S-band EDFA by suppressing C-band ASE in uniformly inverted EDF
(2007)
Cho, Sheng-Lung
;
Chen, Nan-Kuang
;
Chi, Sien
;
光電工程學系
;
Department of Photonics
We demonstrate an efficient S-band erbium-doped fiber amplifier using C-band ASE suppressing filters discretely in a 13.5-m-long uniformly inverted erbium fiber. The saturation output power and the saturation signal input power can be higher than 6 dBm and -3.6 dBm, respectively under the 980 nm pump power of 198 mW.
Influence of fabrication conditions on characteristics of phenanthrenequinone-doped poly(methyl methacrylate) photopolymer for holographic memory
(2014-06-01)
Lin, Shiuan Huei
;
Cho, Sheng-Lung
;
Lin, June-Hua
;
Hsu, Ken Y.
;
Chi, Sien
In this paper, we experimentally investigate the influence of the fabrication conditions on holographic characteristics in phenanthrenequinone-doped poly(methyl methacrylate) (PQ:PMMA) bulk photopolymer. In our investigation, the PQ:PMMA bulk samples are fabricated by use of a two-step thermopolymerization method. We firstly propose to monitor relative viscosity of the monomer solution during the sample preparation to obtain a reliable criterion for material fabrication. We then compare experimentally characteristics of 2-mm thick samples fabricated with different conditions for holographic memory. The results show that the conditions in the first step play a important rule for fabricating bulk PQ:PMMA samples with good optical uniformity. In addition, the conditions in the second step play the rule for controlling the concentration of residual monomer and determine holographic characteristics. These results can provide a useful rule for fabricating bulk PQ:PMMA photopolymers for further applications on volume holographic data storage. (C) 2014 Elsevier B.V. All rights reserved.
Two-wavelength holographic recording in photopolymer using four-energy-level system: experiments and modeling
(2014-11-01)
Lin, Chun-Hua
;
Cho, Sheng-Lung
;
Lin, Shiuan-Huei
;
Chi, Sien
;
Hsu, Ken-Yuh
We investigate a two-wavelength method for recording a persistent hologram in a doped photopolymer. The recording method is based on two separated optical excitations of the four-energy-level system of the doped element, one at lambda = 325 nm as the sensitizing wavelength and the other at lambda = 647 nm as the writing wavelength, allowing for an experimental demonstration of nondestructive readout in phenanthrenequinone-doped poly(methyl methacrylate). Further, a four-energy-level rate equations model is proposed for describing the dynamics of hologram recording. The model successfully explains our experimental finding and further provides a general method to investigate such a two-wavelength holographic recording in photopolymer. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Two-wavelength holographic recording in photopolymer using four-energy-level system: experiments and modeling
(2014-11-01)
Lin, Chun-Hua
;
Cho, Sheng-Lung
;
Lin, Shiuan-Huei
;
Chi, Sien
;
Hsu, Ken-Yuh
We investigate a two-wavelength method for recording a persistent hologram in a doped photopolymer. The recording method is based on two separated optical excitations of the four-energy-level system of the doped element, one at lambda = 325 nm as the sensitizing wavelength and the other at lambda = 647 nm as the writing wavelength, allowing for an experimental demonstration of nondestructive readout in phenanthrenequinone-doped poly(methyl methacrylate). Further, a four-energy-level rate equations model is proposed for describing the dynamics of hologram recording. The model successfully explains our experimental finding and further provides a general method to investigate such a two-wavelength holographic recording in photopolymer. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Two-wavelength holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer
(2012-03-01)
Chen, Po-Lin
;
Cho, Sheng-Lung
;
Lin, June-Hua
;
Lin, Shiuan-Huei
;
Hsu, Ken Y.
Two-wavelength holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer is demonstrated. By using 325 nm laser as a gating illumination during the holographic recording with 647 nm laser, a volume hologram with diffraction efficiency of similar to 4% can be recorded in a 2 mm thick sample. In addition, the Bragg selectivity curve with clear sinc nulls is demonstrated. These results support further applications as recording media for volume holographic device with extended spectral response and selective recording property. (C) 2012 ociety of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.3.030503]
Volume polarization holographic recording in thick photopolymer for optical memory
(2014-06-16)
Lin, Shiuan Huei
;
Cho, Sheng-Lung
;
Chou, Shin-Fu
;
Lin, June Hua
;
Lin, Chih Min
Based on a vector wave theory of volume holograms, dependence of holographic reconstruction on the polarization states of the writing and reading beams is discussed. It is found that under paraxial approximation the circular polarization holograms provide a better distinction of the reading beams. Characteristics of recording polarization holograms in thick phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer are experimentally investigated. It is found that the circular polarization holographic recording possesses better dynamic range and material sensitivity, and a uniform spatial frequency response over a wide range. The performance is comparable to that of the intensity holographic recording in PQ/PMMA. Based on theoretical analyses and the material properties, a polarization multiplexing holographic memory using circularly polarization recording configuration for increasing storage capacity has been designed and experimentally demonstrated. (C) 2014 Optical Society of America