Soliton fiber laser with a hybrid saturable absorber

Stable single- and dual-wavelength fiber laser mode locked and spectrum shaped by a Fabry-Perot saturable absorber

We show that the spectral response of a Fabry-Perot semiconductor saturable absorber depends on laser beam focusing. We used this effect to achieve stable passive mode-locked operation in a simple and environmentally stable fiber laser by introducing spectral filtering and forcing near-resonant operation. By reducing the free spectral range and increasing the nonlinear response of the Fabry-Perot saturable absorber, we obtained dual-wavelength mode-locked operation.

Frequency doubling of femtosecond erbium-fiber soliton lasers in periodically poled lithium niobate

We report efficient frequency doubling of passively mode-locked femtosecond erbium-fiber lasers. Quasi-phase-matched second-harmonic generation in periodically poled lithium niobate is used to generate 8.1 mW of 190-fs (FWHM), 90-pJ pulses at 777 nm with a conversion efficiency greater than can be obtained with existing birefringently phase-matched nonlinear materials. A dispersion-compensation-free soliton oscillator generating transform-limited 230-fs (FWHM) pulses at 1554 nm is used as a pump laser.

Cladding-pumped passive harmonically mode-locked fiber laser

A passive harmonically mode-locked fiber laser cladding pumped by a broad-area diode-laser array is described. Harmonic mode locking is obtained in a frequency range from 33.3 to 128.6 MHz, where the higher frequency limit is imposed because of insufficient available pump power. The maximum pulse jitter in one cavity roundtrip time is between 300 and 50 ps in the whole frequency range, and the sidebands in the frequency domain are suppressed by as much as 50 dB. 600-fs bandwidth-limited pulses with pulse energies of as much as 20 pJ are obtained, giving rise to an average output power as great as 2.5 mW.