title: Single-mode, narrow-linewidth external cavity quantum cascade laser through optical feedback from a partial-reflector.
abstract: An external-cavity (EC) quantum cascade (QC) laser using optical feedback from a partial-reflector is reported. With this configuration, the otherwise multi-mode emission of a Fabry-Perot QC laser was made single-mode with optical output powers exceeding 40 mW. A mode-hop free tuning range of 2.46 cm(-1) was achieved by synchronously tuning the EC length and QC laser current. The linewidth of the partial-reflector EC-QC laser was measured for integration times from 100 μs to 4 seconds, and compared to a distributed feedback QC laser. Linewidths as small as 480 kHz were recorded for the EC-QC laser.
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, NJ 08540, USA. rcendeja@princeton.edu
authors.forename: Richard A
authors.initials: RA
authors.lastname: Cendejas
authors.forename: Mark C
authors.initials: MC
authors.lastname: Phillips
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Myers
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Taubman
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005246:Feedback; D007834:Lasers; D007909:Lenses; D011789:Quantum Theory; D012031:Refractometry / Q000295:instrumentation*