High-power operation of coherently coupled tapered laser diodes in an external cavity

G. Schimmela, I. Doyena, S. Janicota, M. Hannaa, P. Georgesa, G. Lucas-Leclina, J. Deckerb, P. Crumpb, G. Erbertb, S. Kaunga-Nyirendac, D. Mossc, S. Bullc, E.C. Larkinsc, U. Witted, M. Traubd

Published in:

Proc. SPIE 9733, Photonics West, San Francisco, USA, Feb. 13-18, 97330I (2016).

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Abstract:

We demonstrate a rear-side phase-locking architecture with two high-brightness diode lasers. This technique is based on the passive phase-locking of emitters in an external cavity on their rear facet, and their coherent combination on the front facet. Two high-brightness high-power tapered laser diodes are coherently combined using a Michelson-based cavity. The combining efficiency is above 80% and results in an output power of 6.7 W in a nearly diffraction-limited beam. The rear-side architecture is then used with a laser bar of 5 tapered emitters using an interferometric extended cavity, based on a diffractive optical element. We describe the experimental evaluation of the diffractive optical element, and the phase-locked operation of the laser bar.

a Laboratoire Charles Fabry, Institut d’Optique Graduate School, CNRS, Université Paris Saclay, Palaiseau, France
b Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Berlin, Germany
c School of Electrical and Electronic Engineering, University of Nottingham, Nottingham, U.K
d Fraunhofer-Institut fur Lasertechnik, Aachen, Germany

Keywords:

coherent beam combining, passive phase-locking, self-organized extended cavity, diode lasers.