The study of 80 MHz self starting passively mode-locked erbium-doped fiber laser via nonlinear polarization rotation with SESAM

الملخص EN

Erbium-Doped Fiber Laser, EDFL, passively mode-locked via only Nonlinear Polarization Rotation, NPR, and via NPR with Semiconductor Saturable Absorber Mirror, SESAM, is studied.

Self start single pulse train with pulse width of 114 fs and repetition rate (PRR) of 80 MHz has been obtained when 55 cm EDFL, passively mode-locked via NPR only.

Inserting SESAM in EDFL cavity leads to shorten the pulse width up to 88 fs, increases the amplitude stability up to 96% and lower the phase noise jittering to around 26 fsec.

Stable second harmonic self starting passively mode-locked EDFL with pulse width of 284 fs has also been observed only when SESAM was used in the cavity.

Multi-pulsed system passively mode-locked via NPR for EDFL length of 80 cm with time difference between the successive multi-pulses ranged from few picoseconds to nanoseconds, has been observed.

The time difference can be controlled by the polarizer controller and the half wave plate.

Further controlling of the cavity polarization leads to developing the multiple modelocking pulses train to second harmonic mode-locking pulse train with PRR of 160 MHz and pulse width of 156 fs.

Three harmonic superposed trains of modelocked pulse have been achieved only when SESAM added to the cavity.