Browsing by Author "Lee, SK"

Now showing 1 - 2 of 2

A feedback-injected Fabry-Perot laser diode filtering technique for side-mode suppression and linewidth reduction of erbium-doped fiber lasers
(2003-07-15)
Lin, GR
;
Lee, SK
;
光電工程學系
;
Department of Photonics
By adding a fiber-pigtailed Fabry-Perot laser diode (FPLD) into a close-loop erbium-doped fiber amplifier (EDFA) ring cavity. and feedback-injecting the FPLD biased at just below threshold and the EDFA each other via directional couplers, we demonstrate a low-cost band-pass filtering technique for constructing narrow linewidth erbium-doped fiber laser (EDFL) with ultrahigh side-mode suppression ratio (SMSR). Under an output coupling ratio of 90%, the mutually injection-locked EDFL-FPLD link exhibits a maximum output power and SMSR of up to 98.6 mW and 49.6 dB at wavelength 1561.37 nm,. respectively. Wavelength tuning of up to 6 nm can be achieved by tuning the temperature and fine adjusting the below threshold driven current of FPLD. The minimum spectral linewidth at 3dB-decay of as small as 0.017 nm measuring by commercial optical spectrum analyzer with limited resolution bandwidth of 0.01 nm are observed. The stabilities in power, SMSR, peak wavelength of +/-0.01 mW, +/-0.5 dB, and +/-0.025 nm, respectively, are also determined. (C) 2003 Elsevier Science B.V. All rights reserved.
Optically injection mode-locked 1.3 mu m semiconductor optical amplifier fiber ring laser by using gain-switching single-mode FPLD
(2002)
Hsueh, PS
;
Lee, SK
;
Lin, GR
;
光電工程學系
;
Department of Photonics
We demonstrate a novel approach for generating a stable and low polarization-sensitive mode-locked fiber ring laser by using a low-cost Fabry-Perot laser diode (FPLD) as both the intracavity mode-locker and the band-pass filter. The FPLD pulses is seeded into a close-loop semiconductor optical amplifier (SOA) based fiber ring laser for harmonic and rational harmonic mode-locking operation. The SOA biased at 65 mA and 18degreesC combines with an intracavity optically feedback-injected 1.3 mum FPLD biased at 9.4 mA (below threshold current) and 23degreesC via some optical couplers. Picosecond optical pulse with side-mode suppressing ratio of greater than 12 dB are obtained, the measured lindwidth at 3-dB and 10-dB decay are observed to maintain at about 0.04 nm and 0.14 nm, respectively. Narrow-linewidth operation of the SOAFL with optical pulsewidth of 42.1 ps and wavelength tuning range of about 10 nm at repetition rate of 13 GHz has been demonstrated. The optically injection mode-locking scheme also has shown to exhibit low supermode noise, higher average output power and good stability. The optical output power under harmonic mode-locked scheme is about 297 muW. The fluctuation in output power, the SSB phase noise at 1 kHz offset frequency, and the calculated rms timing jitter within the integral region from 0 Hz to 1 KHz are +/-2.5 muW, -82.4 dBc/Hz, and 1.0 ps, respectively.