title: Passive coherent beam combining of quantum-cascade lasers with a Dammann grating.
abstract: An external cavity using a binary phase grating has been developed to achieve coherent combining of five quantum-cascade lasers emitting at 4.65 μm. The grating phase profile is designed to combine five beams of equal intensities into a single beam with a good efficiency (~75%). The performances of this cavity concerning output power, stability, combining efficiency and beam quality are detailed. We report a CW combining efficiency of 66% corresponding to an output power of ~0.5 W with a good beam quality (M(2)<1.6).
authors.affiliation: Thales Research and Technology, 1 Avenue Augustin Fresnel, 91767 Palaiseau Cedex, France. guillaume.bloom@thalesgroup.com
authors.forename: G
authors.initials: G
authors.lastname: Bloom
authors.forename: C
authors.initials: C
authors.lastname: Larat
authors.forename: E
authors.initials: E
authors.lastname: Lallier
authors.forename: G
authors.initials: G
authors.lastname: Lehoucq
authors.forename: S
authors.initials: S
authors.lastname: Bansropun
authors.forename: M-S L
authors.initials: MS
authors.lastname: Lee-Bouhours
authors.forename: B
authors.initials: B
authors.lastname: Loiseaux
authors.forename: M
authors.initials: M
authors.lastname: Carras
authors.forename: X
authors.initials: X
authors.lastname: Marcadet
authors.forename: G
authors.initials: G
authors.lastname: Lucas-Leclin
authors.forename: P
authors.initials: P
authors.lastname: Georges