Frequency stabilization of a semiconductor laser by external phase-conjugate feedback

Feedback phase sensitivity of a semiconductor laser subject to filtered optical feedback: experiment and theory

We investigate experimentally and theoretically the dynamics of a semiconductor laser subject to filtered optical feedback. Depending on the feedback strength we find dynamical regimes with different dependence on the feedback phase. In particular, the influence of the feedback phase on cw emission and on frequency oscillations is characterized experimentally. We also measure the dependence of the filter mirror distance on the frequency oscillations. In general, good agreement between experiment and theory is found.

Characteristics of a high-power broad-area laser operating in a passively stabilized external cavity

We narrowed the spectral bandwidth of our 2 W broad-area laser to 8+/-1 GHz with a coarse tunability of 12 nm centered near 790 nm in an external cavity. Our passively stabilized external cavity was designed for use with high-power semiconductor lasers. The cavity length and mount are modular with a fixed pivot point so that the optical elements can be changed to access a broad frequency spectrum and enable multiple applications. The bandwidth was observed to be dependent on the multimode transverse structure of the laser.