基于双段拼接掺铒光纤种子源的超短脉冲光纤激光器

Abstract This paper reports on an ultrashort pulse femtosecond fiber laser based on mode-locking with a two-seg ment spliced erbium-doped fiber.The laser consists of a seed source a two-stage fiber amplifier and a pulse com pression section.The seed source is a single-walled carbon nanotube (SWCNT) mode-locked erbium-doped fiber la ser which uses a two-segment spliced erbium-doped fiber as the gain medium.This design effectively achieves intra cavity dispersion management and spectral broadening by introducing complementary dispersion.In the amplifier section the first-stage fiber amplifier employs forward pumping while the second-stage uses bidirectional pumping.The amplified pulses are compressed using only 2. 0 m of single-mode fiber ultimately producing femtosecond pulses with a spectral bandwidth of 78.39 nm a pulse width of 49 fs (fitted with a Sech profile) a maximum average out put power of 145. 5 mW after the two-stage amplification a corresponding peak power of 65. 3 kW and a singlepulse energy of 3. 20 nJ.Keywords erbium-doped fiber laser carbon nanotube mode-locking spectral broadening 1