Highly efficient external coherent combining of 975 nm single mode laser diodes in a fully fiber integrated interferometric device

We proposed and demonstrated the coherent phase-locking of two single-mode laser diodes. The originality of the method consists in the use of an Michelson interferometer resonator which selects resonance frequencies leading to a coherent combining. A high power combining efficiency up to 85% has been measured. A high power combining efficiency up to 85% has been measured. This result could be improved by increasing the Q-factor of the laser diode cavities. This brings some novel perspectives for scaling the power of the single-mode laser sources at 975 nm which is of great interest for optical networks and high power devices.