A new type of semiconductor laser based on an InAsSb/InAsSbP double heterostructure and having just a single tuned spectral I line is described for spectroscopy of atmospherically important molecules in the 3100cm-1 region. The lasers are tested using a closed-cycle He-cryostat in the temperature range 12-100 K. The optimal characteristics of the lasers are found to be a temperature range of 17-80 K and a drive current range of 50-400 mA. Under these conditions, the laser emission can be tuned in a single-mode regime over a range greater than 10 cm-1. Experiments are performed to measure the rovibrational absorption spectra of CH3Cl, NH3, OCS and H2O, which prove the generation to be the single-mode one. The estimated spectral emission line-widths vary from 7 to 30 MHz depending on current and from laser to laser

InAsSb/InAsSbP double heterostructure diode lasers for the spectral range of 3.3 μm grown by liquid phase epitaxy have been investigated. Emission spectra, far-field patterns and wavelength tuning versus current have been studied in the wide current range from threshold value Ith up to 3 Ith, at the temperature of liquid nitrogen. Controlled by current wavelength tuning in single-mode lasing has been obtained both towards the shorter wavelengths (up to 4.56 cm−1) and towards the longer wavelengths (up to 0.9 cm−1) at the temperature T=77 K. Comparison of the emission properties of the lasers, driven by different types of current (short pulse current, sawtooth pulse current and in quasi cw regime) showed the same quantum-mechanical nature of current tuning. The theoretical model of this nonlinear optical phenomenon is proposed. The estimated times of current tuning defined mainly by the photon lifetime in the cavity are about 10−9–10−12 s.

A method was used to measure the width of emission lines of a type of semiconductor laser with composition InAsSb/InAsSbP. This type of laser was manufactured specially for absorption high-resolution spectroscopy of gases absorbing in the 2800–3100 cm−1 region. Parameters used for calculation of spectral emission linewidths were obtained using selected rotation-vibration lines of the gaseous molecules N2O, CH3Cl, and OCS. The estimated spectral emission linewidths varied in the range 10–30 MHz in dependence of the current passing and the type of laser.

A report is presented on the development of a single-mode laser based on the InAsSb/InAsSbP double heterostructure and operating at wavelengths of 3.2-3.3 mu m in a temperature range of 12-90 K. The single-mode regime is assumed to be realized due to a smooth optical waveguide formed across the laser cavity in which the radiation flux oscillates and maintains its oscillations and intensity. An analysis is made of the effect of the current-induced shifts of the lasing frequency and the peak of the gain spectrum on the probability of single-mode lasing. Experiments were made on the scanning of OCS, NH3, CH3Cl, and H2O gas media with radiation of the given laser in the frequency range with a record width of 10 cm(-1) (104 A). (C) 2000 MAIK "Nauka/Interperiodica".

A new type of semi-conductor laser with composition InAsSb/InAsSbP is described. This laser was produced for the absorption spectroscopy of atmospherically important molecules in the 3100 cm(-1) region and tested using a closed-cycle He-cryostat in the temperature range 30-80 K. The optimal characteristics of the laser were found to be a heatsink temperature of 62 K and a drive current range of 50-350 mA. Under these conditions, the laser emits single-mode radiation in an exceptionally large wavenumber range of > 10 cm(-1). To test the laser, several experiments were carried out in which the rovibrational absorption spectra of CH3Cl, NH3, OCS and H2O were measured.

Comparative study of threshold current temperature dependence, differential quantum efficiency and light polarization was performed for type I and type II InAsSb/InAsSbP heterostructures as well as for tunneling-injection GaInAsSb/InGaAsSb laser based on the type II broken-gap heterojunction. Experimental evidence of non-radiative Auger-recombination suppression in type II InAsSb/InAsSbP heterolasers with high band-offset ratio Delta E-p/Delta E-e=3.4 was obtained. Reduction of temperature dependence of the threshold current was demonstrated for both kinds of type II lasers. Maximum operation temperature and characteristic temperature T=203 K with T-0=40 K and T=195 K with T-0=47 K were achieved for type II InAsSb/InAsSbP and tunneling-injection p-GaInAsSb/n-InGaAsSb lasers.

III-V mid-infrared lasers: traditional InAsSb/InAsSbP double heterostructures and novel tunnelling injection lasers based on type II broken-gap GaInAsSb/InAs heterojunction are considered. Problems of Auger-recombination suppression and room temperature operation of the lasers are discussed. A theoretical and experimental study of threshold current temperature dependence is presented and a comparative study of limiting operation temperature for traditional and non-traditional laser designs is performed. The presented results open the way for III-V mid-infrared lasers to operate at room temperature.

The mode composition of 1.81-mu m laser radiation from a laser with a p-type GaInAsSb active region at 77 K is investigated. It is shown that the lines can shift in the long- or short-wavelength direction, depending on the ratio of the recombination and thermalization processes in the compounds investigated. It is shown that the range of unimodal lasing currents can be extended effectively by decreasing the cavity length. It is established that the presence of a number of spatially separated recombination channels causes the lasing spectrum to be inhomogeneous. (C) 1996 American Institute of Physics.

The recombination nearby large band-offset staggered lineup N-GaSb/n-GaInAsSb heterojunction was investigated by means of the electroluminescence and carrier lifetime measurements. It was demonstrated that the nature of recombination, tuning rate as well as relation between radiative and non-radiative recombination strongly depend on the N-n band-offset and that its increase improves the carrier localization on the N-n interface.

The temperature dependence of the threshold current density of double-heterostructure lasers, based on the solid solution GaInAsSb, with a thin active region is studied theoretically.It is shown that a new Auger recombination mechanism, which is due to the interaction of current carriers with the heteroboundary, contributes to the threshold current in double-heterostructure structures with a thin active region. It is also shown that at low temperatures the new Auger recombination channel is the main mechanism for nonradiative recombination of carriers. The theoretically computed temperature dependence of the threshold current density is compared with the experimental data. (C) 1995 American Institute of Physics.

The structures and electroluminescence characteristics of new two types of single mode A3B5 semiconductor tunable lasers in the 1.8-3.9 micrometers spectral range have been demonstrated. The first type of tunable diode laser based on quaternary solid solutions GaInAsSb and GaAlAsSb lattice matched to GaSb substrate covers 1.8-2.4 micrometers spectral range. Such tunable 1.8-2.4 micrometers lasers have single mode or quasi-single mode operation in the wide temperature range from 1.6 to 300K. The second type of tunable diode laser based on multiple component InPAsSb/InAsSb lattice matched or mismatched to InAs substrate covers 2.8-3.9 micrometers spectral range, which was not available for diode laser spectroscopy until nowadays. Such tunable 2.8-3.9 micrometers lasers have CW single mode operation up to 100K and pulse operation up to 180K. These lasers can be the key devices for diode laser spectroscopy and sensitive detection of pollutants.

The lasing characteristics of new single mode A 3 B 5 semiconductor tunable lasers for the 1.8 to 3.9 micrometers wavelength region have been demonstrated. These lasers can be the key devices for diode laser spectroscopy and sensitive detection of pollutants.

Lasing has been obtained in the wavelength range 2.7–3.9 μm in double heterostructure diode lasers with an active region made of InAs alloys. The devices were grown by liquid-phase epitaxy. Typical values of threshold current at 80 K were as low as 40 mA and the maximum operating temperature was 180 K. The blue shift of lasing modes was observed with current. This was explained by the increase of the carrier density in the active region above threshold due to intervalence band absorption.

The laser structures were grown by liquid phase epitaxial growth (LPE) on InAs (100) substrate and consisted of two cladding layers of the InAsSbP alloy with InP mole fraction and active layer which was made either of InAsSbP with a lower band gap or of the InAsSb solid solution. This report is devoted to study the temperature dependence of the threshold current and laser tunability by current

The electroluminescence of heterostructures with a biased N-GaSb/n-GaInAsSb heterojunction has been studied. The results show that this luminescence stems from a competition between band-band bulk and interfacial recombination. The relation between the radiative and nonradiative recombination channels near a biased N-n heterojunction with a narrow gap-GaInAsSb region is at its optimum when the discontinuity of the conduction band at the junction is less than DELTAE(c) = 200 meV The introduction of an intermediate layer makes it possible to increase the external quantum yield of the emission in comparison with that of structures without an intermediate layer.

The authors report an InPAsSb laser for the spectral range of 2.8-3.6 μm for application to diode laser spectroscopy (DLS). For high resolution spectroscopy it is necessary to have single mode or quasi single mode lasers with continuous tuning of the emission wavelength by current or/and by temperature. The important parameter for DLS is the shift of a longitudinal mode position with current and temperature, which is discussed. Good mode structure of the laser emission, relatively high optical power and a possibility of continuous wave operation above liquid nitrogen temperature are the attractive factors for spectroscopy. First experiments showed that the lasers can be successfully used for DLS