title: Two-state semiconductor laser self-mixing velocimetry exploiting coupled quantum-dot emission-states: experiment, simulation and theory.
abstract: We exploit the coupled emission-states of a single-chip semiconductor InAs/GaAs quantum-dot laser emitting simultaneously on ground-state (λ(GS) = 1245 nm) and excited-state (λ(ES) = 1175 nm) to demonstrate coupled-two-state self-mixing velocimetry for a moving diffuse reflector. A 13 Hz-narrow Doppler beat frequency signal at 317 Hz is obtained for a reflector velocity of 3 mm/s, which exemplifies a 66-fold improvement in width as compared to single-wavelength self-mixing velocimetry. Simulation results reveal the physical origin of this signal, the coupling of excited-state and ground-state photons via the carriers, which is unique for quantum-dot lasers and reproduce the experimental results with excellent agreement.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Gioannini
authors.forename: Marius
authors.initials: M
authors.lastname: Dommermuth
authors.forename: Lukas
authors.initials: L
authors.lastname: Drzewietzki
authors.forename: Igor
authors.initials: I
authors.lastname: Krestnikov
authors.forename: Daniil
authors.initials: D
authors.lastname: Livshits
authors.forename: Michel
authors.initials: M
authors.lastname: Krakowski
authors.forename: Stefan
authors.initials: S
authors.lastname: Breuer
mesh_terms: D003198:Computer Simulation; D004867:Equipment Design; D054023:Lasers, Semiconductor; D017785:Photons; D045663:Quantum Dots; D012212:Rheology / Q000295:instrumentation*