title: Intra-pulse beam steering in a mid-infrared quantum cascade laser.
abstract: The intra-pulse measurements of the beam steering in an AlGaAs/GaAs quantum cascade laser are presented in this paper. The experimental results are explained by a two-mode theoretical model. The near field of the laser radiation is calculated according to the effective index method and transposed to the far field numerically according to Huygens principle. The maximal observed value of deflection of the beam has been found to be [Formula: see text]. For supply currents in the range from 1.6 to 2.4 times the threshold the beam steering occurs only on one side of the resonator axis, and stays is the same for all current values. For higher supply current, it occurs alternately on both sides and exhibits a bistability. The time period of the beam direction change has been found to be about 40 ns for the lowest current and was decreasing with the current increase to about 20 ns.
authors.affiliation: Institute of Electron Technology, al. Lotników 32/46, 03-668  Warsaw, Poland.
authors.forename: Emilia
authors.initials: E
authors.lastname: Pruszyńska-Karbownik
authors.affiliation: Institute of Electron Technology, al. Lotników 32/46, 03-668  Warsaw, Poland.
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Regiński
authors.affiliation: Institute of Electron Technology, al. Lotników 32/46, 03-668  Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Karbownik
authors.affiliation: Institute of Electron Technology, al. Lotników 32/46, 03-668  Warsaw, Poland.
authors.forename: Bohdan
authors.initials: B
authors.lastname: Mroziewicz
keywords: Beam steering; Far field; Quantum cascade laser