Chien-Hung Yeh

Chien-Hung Yeh


Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 October 2013 in Optics Express
Verified
Journal Article
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CYChien-Hung Yeh
Chien-Hung Yeh
YLYen-Liang Liu
Yen-Liang Liu
Chi-Wai ChowChi-Wai Chow
Chi-Wai Chow
Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

15 September 2022 in Journal of Lightwave Technology
Verified
Journal Article
Closed access
Chi-Wai ChowChi-Wai Chow
Chi-Wai Chow
You-Chia ChangYou-Chia Chang
You-Chia Chang
SKSheng-I Kuo
Sheng-I Kuo
PKPin-Cheng Kuo
Pin-Cheng Kuo
JWJu-Wei Wang
Ju-Wei Wang
YLYang Liu
Yang Liu
We put forward and present a demonstration of an actively controlled optical beam steering optical wireless communication (OWC) system based on an integrated actively steerable optical phased array (OPA). We theoretically and experimentally analyze the emitted optical beam full-width-half-maximum (FWHM) divergence angle and field-of-view (FOV) of the proposed integrated actively steerable OPA. Experimental results show that the beam steering can be achieved over a range of 17° with a minimum optical beam FWHM divergence angle of 1.49°. Besides, the integrated OPA chip design, beam forming optimization, packaging, as well as temperature stabilization are also discussed. Genetic Algorithm (GA) is utilized to optimize the applied voltages for the 30 phase shifters to produce low-divergence optical beams in different directions. A proof-of-concept bit-error-rate (BER) measurement using 10 Gbit/s on-off-keying (OOK) signal is also carried out, and the beam steered optical signal satisfying the pre-forward error correction BER limit (pre-FEC BER = 3.8 × 10 −3 ) is achieved.

22 January 2007 in Optics Express
Verified
Journal Article
Closed access
PDF file
CYChien-Hung Yeh
Chien-Hung Yeh
THT. T. Huang
T. T. Huang
HCH.-C. Chien
H.-C. Chien
CKC.-H. Ko
C.-H. Ko
Sien ChiSien Chi
Sien Chi
We propose and demonstrate a tunable and stable single-longitudinal-mode (SLM) erbium fiber laser with a passive triple-ring cavity structure in S-band operation. The proposed laser is fundamentally structured by using three different lengths of ring cavities, which serve as the mode filters. When a mode-restricting intracavity fiber Fabry-Perot tunable filter (FFP-TF) is combined, the proposed resonator can guarantee a tunable and stable SLM laser oscillation. Moreover, the performances of the output power, wavelength stability, tuning range, and side-mode suppression ratio (SMSR) are studied.

20 August 2019 in Optics Express
Verified
Journal Article
Closed access
PDF file
LWLiang-Yu Wei
Liang-Yu Wei
Chi-Wai ChowChi-Wai Chow
Chi-Wai Chow
GCGuan-Hong Chen
Guan-Hong Chen
YLYang Liu
Yang Liu
CYChien-Hung Yeh
Chien-Hung Yeh
CHChin-Wei Hsu
Chin-Wei Hsu
Visible light communication (VLC) can provide a dedicated, secure, and high data rate wireless transmission link. It has gained considerable attentions recently, and is considered as one of the promising technologies for beyond 5G mobile and wireless communications. In this work, we demonstrate a VLC system with a recorded data rate of 40.665 Gbit/s using tricolor red, green and blue (RGB) laser diodes (LDs) and polarization multiplexing. 2 m free-space transmission distance is achieved. The implementation of bit-loading, power-loading, and polarization multiplexing are discussed. Experimental bit-error-ratio (BER) results show that each of the 6 polarization and wavelength de-multiplexed channels can achieve the forward-error-correction (FEC) requirement.

7 May 2020 in IEEE Photonics Journal
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Journal Article
Open access
CHChong-You Hong
Chong-You Hong
YWYu-Chun Wu
Yu-Chun Wu
YLYang Liu
Yang Liu
Chi-Wai ChowChi-Wai Chow
Chi-Wai Chow
CYChien-Hung Yeh
Chien-Hung Yeh
YCYi-Yuan Chen
Yi-Yuan Chen
We put forward and demonstrate a angle-of-arrival (AOA) based visible-light-positioning (VLP) system using quadrant-solar-cell (QSC) and third-order ridge regression machine learning (RRML) to improve the positioning accuracy.

16 January 2015 in Optics Express
Verified
Journal Article
Open access
PDF file
CYChien-Hung Yeh
Chien-Hung Yeh
HCHsing-Yu Chen
Hsing-Yu Chen
Chi-Wai ChowChi-Wai Chow
Chi-Wai Chow
YLYen-Liang Liu
Yen-Liang Liu
To increase the traffic rate in phosphor-LED visible light communication (VLC), a multi-band orthogonal frequency division multiplexed (OFDM) modulation is first proposed and demonstrated. In the measurement, we do not utilize optical blue filter to increase modulation bandwidth of phosphor-LED in the VLC system. In this proposed scheme, different bands of OFDM signals are applied to different LED chips in a LED lamp, this can avoid the power fading and nonlinearity issue by applying the same OFDM signal to all the LED chips in a LED lamp. Here, the maximum increase percentages of traffic rates are 41.1%, 17.8% and 17.8% under received illuminations of 200, 500 and 1000 Lux, respectively, when the proposed three-band OFDM modulation is used in the VLC system. In addition, the analysis and verification by experiments are also performed.