title: X-ray studies and time-resolved photoluminescence on optically pumped antimonide-based midinfrared type-II lasers.
abstract: We report on high-resolution X-ray diffraction and time-resolved photoluminescence (TR-PL) studies of antimonide-based midinfrared (MIR) type-II laser samples. A structural characterization taking into account asymmetrical strain, layer tilting, and relaxation enables an accurate determination of the average lattice constant of the active region and the composition of the cladding layers. By designing the antimonide-to-arsenide interfaces, we achieve exact lattice matching of the active region to the substrate. Non-radiative recombination processes are investigated with time-resolved photoluminescence. The samples are also characterized under optically pumped laser operation. By an examination of the time-integrated and time-resolved amplified spontaneous emission (TR-ASE), we investigate the modal gain and gain dynamics. The variable stripe length method is combined with the TR-PL approach. Compared to the time-integrated gain spectra the spectral dependence of the maximum and minimum time-resolved gain shows a broad plateau. The full width half maximum (FWHM) of the TR-ASE pulse is 5.5 +/- 0.5 ps. Thus, short pulses in this range should be achievable upon laser operation. The active regions of the laser structures investigated here are promising subunits of type-II quantum cascade lasers.
authors.affiliation: Integrated Optics and Microoptics Research Group, Physics Department, Kaiserslautern University of Technology, Erwin-Schroedinger-Str. 46, D-67663 Kaiserslautern, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Schwender
authors.forename: Jan Oliver
authors.initials: JO
authors.lastname: Drumm
authors.forename: Goetz
authors.initials: G
authors.lastname: Hoffmann
authors.forename: Birgit
authors.initials: B
authors.lastname: Vogelgesang
authors.forename: Henning
authors.initials: H
authors.lastname: Fouckhardt
mesh_terms: D000965:Antimony; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D007834:Lasers; D008163:Luminescent Measurements / Q000295:instrumentation; D013055:Spectrophotometry, Infrared / Q000295:instrumentation; D013997:Time Factors; D014961:X-Ray Diffraction / Q000295:instrumentation
chemical_list: D000965:Antimony