Delay-Time-Tunable Actively and Regeneratively Mode-Locked Erbium-Doped Fiber Lasers

• Main Authors: Yao-Ling Cheng, 鄭耀齡
• Other Authors: Gong-Ru Lin
• Format: Others
• Language: en_US
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/01522696831327114308

碩士 === 大同大學 === 光電工程研究所 === 89 === In this thesis we demonstrate for the first time a delay-time tunable, actively and regenerately mode-locked erbium-doped fiber ring laser (ML-EDFL). Such a new class of ML-EDFL systems are integrated by using a typical ML-EDFL set and a frequency-translated delay-locked loop (DLL). The theoretical and experimental analysis of a new type of broad-band microwave phase shifter implemented by using frequency-translated DLL and frequency prescalers are demonstrated. By adding a continuously tunable offset voltage prior to the loop filter (LF) in a phase-locked loop (PLL), a novel DLL for accurate control of the phase of microwave signals generated from frequency-locked VCO can be achieved. By changing the voltage from —3.35 volts to 3.6 volts of the DLL, the maximum tuning range of the phase and the delay-time of optical pulse-train generated from actively ML-EDFL system repeated at 500 MHz can be up to 340º and 1.9ns (nearly 1 period) respectively under a tuning responsivity of 0.27 ps/mV. The regeneratively ML-EDFL with pulsewidth and spectral width, and delay-time tuning range of 58 ps, 0.16 nm, and 1.9 ns respectively are reported.