An evanescent-coupling approach to making stable fiber-coupled semiconductor lasers

Abstract

We present a fiber-coupled GaAs laser, which works on the principle of evanescent coupling between a semiconductor antiresonant reflecting optical waveguide and a side-polished single-mode fiber. Compared to conventional fiber-coupled semiconductor lasers, these devices enjoy more relaxed alignment tolerances and simpler packaging, as well as high immunity to catastrophic mirror damage that limits the maximum power output of most edge-emitting lasers. Moreover, the small coupling window here provides an inherent filter that guarantees wavelength stability without any gratings. The initial data show stable single-frequency operation with more than 27dB side-mode suppression ratio and a small thermal coefficient of 0.06nm∕°C.