Title

High Performance 5.6Μm Quantum Cascade Lasers

Keywords

Infrared; Quantum cascade laser

Abstract

5.6 μm quantum cascade lasers based on Al0.78In0.22As/In0.69Ga0.31 As active region composition with measured pulsed room temperature wall plug efficiency of 28.3% are reported. Injection efficiency for the upper laser level of 75% was measured for the new design by testing devices with variable cavity length. Threshold current density of 1.7kA/cm2 and slope efficiency of 4.9W/A were measured for uncoated 3.15mm × 9μm lasers. Threshold current density and slope efficiency dependence on temperature in the range from 288K to 348K for the new structure can be described by characteristic temperatures T0 ∼ 140K and T1 ∼710K, respectively. Experimental data for inverse slope efficiency dependence on cavity length for 15-stage quantum cascade lasers with the same design are also presented. When combined with the 40-stage device data, the new data allowed for separate evaluation of the losses originating from the active region and from the cladding layers of the laser structure. Specifically, the active region losses for the studied design were found to be 0.77 cm-1, while cladding region losses - 0.33 cm-1. The data demonstrate that active region losses in mid wave infrared quantum cascade lasers largely define total waveguide losses and that their reduction should be one of the main priorities in the quantum cascade laser design.

Publication Date

1-1-2017

Publication Title

Proceedings of SPIE - The International Society for Optical Engineering

Volume

10123

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1117/12.2250922

Socpus ID

85020282326 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85020282326

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