Browsing by Author "Yang, Zi-Qing"

Now showing 1 - 7 of 7

A fiber Bragg grating based passive semicircular sensor architecture with fault monitoring
(2019-03-01)
Yeh, Chien-Hung
;
Chang, Yao-Jen
;
Huang, Tzu-Jung
;
Yang, Zi-Qing
;
Chow, Chi-Wai
In the investigation, we investigate a fiber Bragg grating (FBG) based semicircular sensor architecture with fiber fault monitoring experimentally. Two erbium-doped fiber amplifiers (EDFAs) are used in the monitoring center to generate a broadband light source for sensing the strain and temperature simultaneously. Here, we utilize six FBG based sensors with different reflected wavelength for proof-of-concept demonstration. There is no optical filter used in the FBG sensor system for wavelength-selection. In addition, the proposed sensor system can monitor one to two fiber faults. In the measurement, the temperature-and strain-induced changes are also analyzed and discussed. Therefore, the proposed multiple FBG based semicircular sensor system not only can sense the temperature and strain simultaneously, but also can be used to monitor where is the fiber fault.
Erbium-doped fiber dual-ring laser with stable single-longitudinal-mode and 55-nm tuning range
(2018-10-01)
Yeh, Chien-Hung
;
Yang, Zi-Qing
;
Huang, Tzu-Jung
;
Chow, Chi-Wai
;
Chang, Yao-Jen
In the investigation, we propose and demonstrate a stabilized and wavelength-selectable erbium-doped fiber (EDF) compound-ring laser with single-longitudinal-mode (SLM) oscillation covering both C-band and L-band ranges. Here, the dual-ring-cavity (DRC) scheme with an unpumped EDF-based saturable absorber (SA) is proposed in the EDF laser to guarantee SLM output. The proposed DRC of EDF laser can produce the mode-filter and ultra-narrowband auto-tracking filter effects to suppress the densely multi-longitudinal-mode (MLM) and extend the effective gain of EDF in a wavelength range of 1525.0-1580.0 nm. In addition, the observed output stabilities of power and wavelength in the proposed EDF DRC laser are also experimented and discussed. (C) 2018 Elsevier Ltd. All rights reserved.
Stable Single-Longitudinal-Mode Erbium Fiber Ring Laser Utilizing Self-Injection and Saturable Absorber
(2017-12-01)
Yeh, Chien-Hung
;
Huang, Tzu-Jung
;
Yang, Zi-Qing
;
Chow, Chi-Wai
;
Chen, Jing-Heng
In this work, we demonstrate a wavelength-tunable erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) output. Here using the self-injection method and unpumped EDF-based saturable absorber can suppress other densely side-mode to achieve SLM. Hence, the output power and optical signal-to-noise ratio of proposed EDF ring laser are between -7.1 and 2.1 dBm and 30.1 and 36.5 dB in the tuning range of 1525.0 to 1574.0 nm, respectively. According to the proposed EDF laser structure, the wavelength operation range can extend to shorter L-band from C-band. Moreover, the output stability of the proposed EDF ring laser is also executed experimentally.
Switchable dual-wavelength single-longitudinal-mode erbium fiber laser utilizing a dual-ring scheme with a saturable absorber
(2018-06-01)
Yang, Zi-Qing
;
Huang, Tzu-Jung
;
Chang, Yao-Jen
;
Yeh, Chien-Hung
;
Chow, Chi-Wai
In this work, we propose and demonstrate a switchable dual-wavelength erbium-doped fiber (EDF) ring laser with stable single-longitudinal-mode (SLM) output. Here, a dual-ring (DR) structure with an unpumped EDF of 2 m is designed to achieve SLM oscillation. Five fiber Bragg gratings (FBGs) are applied in the laser cavity serving as the reflective element to generate different dual-wavelength outputs. In the measurement, six sets of generated dual-wavelengths with various mode-spacing (Delta lambda) can be achieved via the five FBGs. Additionally, the stability performance of the proposed EDF DR laser is also demonstrated.
Using multi-ring structure for suppression of mode competition in stable single-longitudinal-mode erbium fiber laser
(2017-12-28)
Yeh, Chien-Hung
;
Huang, Tzu-Jung
;
Yang, Zi-Qing
;
Chow, Chi-Wai
;
光電工程學系
In this demonstration, a stable and tunable single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser with multiple-ring configuration is proposed and investigated. The proposed compound-ring structure can create different free spectrum ranges (FSRs) to result in the modefilter effect based on the Vernier effect for suppressing the other modes. Additionally, the output stabilization of power and wavelength in the proposed EDF multiple-ring laser are also discussed.
Utilizing wheel-ring architecture for stable and selectable single-longitudinal-mode erbium fiber laser
(2018-03-01)
Yeh, Chien-Hung
;
Yang, Zi-Qing
;
Huang, Tzu-Jung
;
Chow, Chi-Wai
;
光電工程學系
To achieve a steady single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser, the wheel-ring architecture is proposed in the laser cavity. According to Vernier effect, the proposed wheel-ring can produce three different free spectrum ranges (FSRs) to serve as the mode-filter for suppressing the densely multi-longitudinal-mode (MLM). Here, to complete wavelength-tunable EDF laser, an optical tunable bandpass filter (OTBF) is utilized inside the cavity for tuning arbitrarily. In addition, the entire output performances of the proposed EDF wheel-ring laser are also discussed and analyzed experimentally. (C) 2017 Elsevier B.V. All rights reserved.
Wavelength-selectable and steady single-mode erbium-doped fiber multiple ring laser
(2017-11-01)
Yeh, Chien-Hung
;
Yang, Zi-Qing
;
Huang, Tzu-Jung
;
Chow, Chi-Wai
;
Chen, Jing-Heng
To achieve a stable and selectable C-band erbium-doped fiber (EDF) laser with single-longitudinal-mode output, a multiple ring architecture is proposed and demonstrated experimentally. In this work, we design a passively quadruple-ring structure in the cavity of an EDF laser to produce a Vernier effect with a mode filter for suppressing the multimode spikes significantly. In addition, the output performance and stability of the proposed EDF ring laser are discussed.