Temperature-controller-free FDML laser based on adaptive sweep rate tuning by KTN scanner

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 (KTa1-xNbxO3) 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.