Browsing by Author "Lin, GC"

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Improving the quantum efficiency of erbium-doped fiber laser by using a low-loss tipped fiber splicing process
(2003-09-01)
Lin, GR
;
Lin, GC
;
光電工程學系
;
Department of Photonics
A tipped single-mode fiber (SMF) structure is employed to reduce the fusion-splicing loss induced at the interface between SMFs and Erbium-doped fibers (EDFs). By fusing the EDF and the tipped SMF with lens-like end face at once, the optimized fusion-splicing loss of as low as 0.2 similar to 0.29 dB is obtained. An improvement on splicing loss of up to 0.46 dB is obtained as compared to the conventional EDF/SMF fusion geometry. The effects of tapered angle and radius of curvature at the end face of tipped fiber on the optimization of fusion-splicing loss are compared. The erbium-doped fiber laser with maximum quantum efficiency of 2.75% is reported by using the proposed splicing technology.
Optical-pulse-injection-iniduced 40 GHz photonic frequency multiplication in erbium-doped fiber laser
(2004-08-01)
Lin, GR
;
Lin, GC
;
Wu, JR
;
光電工程學系
;
Department of Photonics
The generation of a 40 GHz regeneratively amplified and frequency-multiplied optical pulse train from an erbium-doped fiber ring laser is demonstrated. This is achieved by seeding a I GHz gain-switched Fabry-Perot laser diode and detuning its repetition frequency to coincide with the harmonic resonant cavity mode. The peak power of frequency-multiplied erbium-doped fiber lasers (EDFL) pulses increases from 80 mW to 230 mW as the modulation level of the Fabry-Perot laser diode (FPLD) increases from 18 dBm to 30 dBm. The pulsewidth and peak power are 10 ps and 5 mW at a repetition rate of 40 GHz. The EDFL longitudinal mode frequency fluctuation is within +/-2.5 kHz during 2 h. The frequency-multiplied EDFL pulses exhibit relatively low phase noises of -95 dBc/Hz and -120 dBc/Hz at offset frequencies of 10 kHz and I MHz, respectively. The associated timing jitter of the EDFL pulses exponentially increases from 0.6 ps to beyond 5.8 ps as the frequency multiplication order increases from I to 40.