Title :
High-repetition-rate optical pulse generation using a rational harmonic mode-locked fiber laser
Author :
Wu, Chiming ; Dutta, Niloy K.
Author_Institution :
Dept. of Phys., Connecticut Univ., Storrs, CT, USA
Abstract :
Rational harmonic mode locking takes place in an actively mode-locked fiber laser when the modulation frequency f/sub m/=(n+1/p)f/sub c/, where n and p are both integers and f/sub c/ is the inverse of the cavity round-trip time, the 22nd order of rational harmonic mode locking has been observed when f/sub m//spl ap/1 GHz. An optical pulse train with a repetition rate of 40 GHz has been obtained using a modulation frequency f/sub m/=10 GHz. The theory of rational harmonic mode locking has also been developed. The stability of the mode-locked pulses is improved considerably when a semiconductor optical amplifier is incorporated into the fiber laser cavity. The supermode noise in the RF spectrum of a mode-locked laser is removed for a certain range of current in the semiconductor optical amplifier.
Keywords :
fibre lasers; laser cavity resonators; laser mode locking; laser modes; laser noise; optical modulation; optical pulse generation; RF spectrum; actively mode-locked fiber laser; cavity round-trip time; fiber laser cavity; high-repetition-rate optical pulse generation; mode-locked pulse stability; modulation frequency; optical pulse train; rational harmonic mode locking; rational harmonic mode-locked fiber laser; repetition rate; semiconductor optical amplifier; supermode noise; Fiber lasers; Frequency modulation; Laser mode locking; Laser noise; Laser stability; Laser theory; Optical pulse generation; Optical pulses; Semiconductor lasers; Semiconductor optical amplifiers;
Journal_Title :
Quantum Electronics, IEEE Journal of
