title: Direct link of a mid-infrared QCL to a frequency comb by optical injection.
abstract: A narrow-linewidth comb-linked nonlinear source is used as master radiation to injection lock a room-temperature mid-infrared quantum cascade laser (QCL). This process leads to a direct lock of the QCL to the optical frequency comb, providing the unique features of narrow linewidth, absolute frequency, higher output power, and wide mode-hop-free tunability. The QCL reproduces the injected radiation within more than 94%, with a reduction of the frequency-noise spectral density by 3 to 4 orders of magnitude up to about 100 kHz, and a linewidth narrowing from a few MHz to 20 kHz.
authors.affiliation: Istituto Nazionale di Ottica (INO), Consiglio Nazionale delle Richerche (CNR), Firenze FI, Italy. simone.borri@ino.it
authors.forename: S
authors.initials: S
authors.lastname: Borri
authors.forename: I
authors.initials: I
authors.lastname: Galli
authors.forename: F
authors.initials: F
authors.lastname: Cappelli
authors.forename: A
authors.initials: A
authors.lastname: Bismuto
authors.forename: S
authors.initials: S
authors.lastname: Bartalini
authors.forename: P
authors.initials: P
authors.lastname: Cancio
authors.forename: G
authors.initials: G
authors.lastname: Giusfredi
authors.forename: D
authors.initials: D
authors.lastname: Mazzotti
authors.forename: J
authors.initials: J
authors.lastname: Faist
authors.forename: P
authors.initials: P
authors.lastname: De Natale