title: Electrical modulation of the complex refractive index in mid-infrared quantum cascade lasers.
abstract: We have demonstrated an integrated three terminal device for the modulation of the complex refractive index of a distributed feedback quantum cascade laser (QCL). The device comprises an active region to produce optical gain vertically stacked with a control region made of asymmetric coupled quantum wells (ACQW). The optical mode, centered on the gain region, has a small overlap also with the control region. Owing to the three terminals an electrical bias can be applied independently on both regions: on the laser for producing optical gain and on the ACQW for tuning the energy of the intersubband transition. This allows the control of the optical losses at the laser frequency as the absorption peak associated to the intersubband transition can be electrically brought in and out the laser transition. By using this function a laser modulation depth of about 400 mW can be achieved by injecting less than 1 mW in the control region. This is four orders of magnitude less than the electrical power needed using direct current modulation and set the basis for the realisation of electrical to optical transducers.
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot-CNRS, UMR 7162, Paris, France. jean.teissier@gmail.com
authors.forename: J
authors.initials: J
authors.lastname: Teissier
authors.forename: S
authors.initials: S
authors.lastname: Laurent
authors.forename: C
authors.initials: C
authors.lastname: Manquest
authors.forename: C
authors.initials: C
authors.lastname: Sirtori
authors.forename: A
authors.initials: A
authors.lastname: Bousseksou
authors.forename: J R
authors.initials: JR
authors.lastname: Coudevylle
authors.forename: R
authors.initials: R
authors.lastname: Colombelli
authors.forename: G
authors.initials: G
authors.lastname: Beaudoin
authors.forename: I
authors.initials: I
authors.lastname: Sagnes
mesh_terms: D004867:Equipment Design; D007259:Infrared Rays; D054023:Lasers, Semiconductor; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D014159:Transducers