title: Tapered 4.7 μm quantum cascade lasers with highly strained active region composition delivering over 4.5 watts of continuous wave optical power.
abstract: A strain-balanced, Al0.7In0.22As/In0.72Ga0.28As/InP quantum cascade laser structure, designed for light emission at 4.7µm using the non-resonant extraction design approach, was grown by molecular beam epitaxy. Laser devices were processed in tapered buried heterostructure geometry and then mounted on AlN/SiC composite submounts using hard solder. A 10 mm long laser with 7.5µm-wide central section tapered up to 20µm at laser facets generated over 4.5W of single-ended CW/RT optical power at 283K. Maximum wallplug efficiency of 16.3% for this laser was reached at 4W level. Reliability of over 2,000h has been demonstrated for an air-cooled system delivering optical power of 3W in a collimated beam with overall system efficiency exceeding 10%.
authors.affiliation: Pranalytica, Inc., 1101 Colorado Ave., Santa Monica, California 90401, USA.
authors.forename: Arkadiy
authors.initials: A
authors.lastname: Lyakh
authors.forename: Richard
authors.initials: R
authors.lastname: Maulini
authors.forename: Alexei
authors.initials: A
authors.lastname: Tsekoun
authors.forename: Rowel
authors.initials: R
authors.lastname: Go
authors.forename: C Kumar N
authors.initials: CK
authors.lastname: Patel