Stabilization of a Fourier domain mode-locked (FDML) laser was achieved in a wide temperature range of over 30 degrees by adaptively tuning the sweep rate without using any complicated or massive temperature control equipment. The proposed FDML laser in a fiber ring cavity configuration consists of an optical tunable filter based on a KTN (KTa<sub>1-x</sub>Nb<sub>x</sub>O<sub>3</sub>) scanner. The FDML laser operates at the sweep rate of around 200 kHz. The output properties show an output power of 2 mW and coherence lengths of 8.5 mm for the sweep range of 100 nm and 11 mm for that of 80 nm at the center wavelength of 1300 nm.
We report on the use of a Semiconductor Disk Laser (SDL) as a seed laser for an Ytterbium-Doped Photonic Bandgap Fiber (Yb-PBGF) amplifier in a Master-Oscillator Power-Amplifier (MOPA) configuration. The SDL comprised a GaInAs/GaAs/GaAsP gain chip, a 1-mm-thick etalon for mode selection, and a 3-mm-thick birefringent filter for wavelength tuning. The fiber amplifier consisted of an Yb-doped core surrounded by a structure of periodically arranged germanium rods with a pitch of 10.2 μm, and to maintain the polarization, the fiber comprised two boron rods. The output of the MOPA-configuration was 31 W and the linewidth of the amplifier output was 149±31 kHz.
1178 nm single-frequency amplification by Yb-doped photonic bandgap fiber has been demonstrated. 24.6 W
output was obtained without stimulated Brillouin scattering. 1.8 dB suppression of Brillouin gain by an acoustic
antiguiding effect has been found in the low-index core antiresonant reflecting optical waveguide.