title: Narrow-linewidth quantum cascade laser at 8.6 μm.
abstract: We report on a narrow-linewidth distributed-feedback quantum cascade laser at 8.6 μm that is optical-feedback locked to a high-finesse V-shaped cavity. The spectral purity of the quantum cascade laser is fully characterized using a high-sensitivity optical frequency discriminator, leading to a 1 ms linewidth of less than 4 kHz and a minimum laser frequency noise spectral density as low as 0.01 Hz2/Hz for Fourier frequencies larger than 100 kHz. The cumulative standard deviation of the laser intensity is better than 0.1% over an integration bandwidth from 2 Hz to 100 MHz.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Fasci
authors.forename: Nicola
authors.initials: N
authors.lastname: Coluccelli
authors.forename: Marco
authors.initials: M
authors.lastname: Cassinerio
authors.forename: Alessio
authors.initials: A
authors.lastname: Gambetta
authors.forename: Laurent
authors.initials: L
authors.lastname: Hilico
authors.forename: Livio
authors.initials: L
authors.lastname: Gianfrani
authors.forename: Paolo
authors.initials: P
authors.lastname: Laporta
authors.forename: Antonio
authors.initials: A
authors.lastname: Castrillo
authors.forename: Gianluca
authors.initials: G
authors.lastname: Galzerano