S. N. Biswas

Effect of wave confinement on the threshold current in heterestructure injection lasers

The influence of wave confinement, on the threshold variation with active region thickness in heterostucture injectjoun lasers is studied by assuming a simplified model of electromagnetic wave propagation through such lasers. It is found that the threshold variation is predominantly determined by the effects of wave confinement. The analysis, though approximate yields results in reasonablc agreement with experimental observation.

Doping dependence of photon yield as a function of excitation energy in optically-excited n-type GaAs at 300°K

Abstract The doping dependence of photon yield as a function of the energy of exciting radiation in optically-excited n-type GaAs at 300°K is determined theoretically. The procedure of determination is reasonably justified by comparing the dependence with the experimental data reported elsewhere. It is found that the photon yield becomes maximum at a value of the doping eoncentrfttion (6 × 1017 cm−3which is more or less independent of tho energy of the exciting radiation and decreases at a given value of the doping concentration with increasing excitation energies above the absorption edge.

Effect of increasing beam voltage on the internal quantum efficiency of spontaneous emission in electron-beam-excited p-type GaAs

Abstract The dependence of the internal quantum efficiency of spontaneous emission on the beam voltage in electron-beam-excited p-type GaAs ia theoretically determined. The procedure of determination is justified through reasonable agreement of the quantum efficiencies estimated for a beam voltage of 15 kv at 77 and 300°K with those determined experimentally.

Temperature dependence of the internal quantum efficiency of spontaneous emission in p-type GaAs excited by a 30 kV electron beam

Abstract The temperature dependence of the internal quantum efficiency of spontaneous emission in p-type GaAs of different doping concentrations excited by a 30 kV electron beam is theoretically determined. The procedure of determination is justified through reasonable agreement of the quantum efficiencies estimated for a beam voltage of 15 kV at 77 and 300°K with those determined experimentally.

Doping dependence of the linewidth of spontaneous emission from electron-beam-excited n-type GaAs at 300°K

Abstract The doping dependence of the linewidth of spontaneous emission from n-type GaAs excited by a 40 kV electron beam at 300°K is theoretically determined. It is found that the dependence is in reasonable agreement with the experimental observation only when the effect of reabsorption of photons is taken into consideration.

Spectral distribution of the spontaneous emission from electron-beam-excited semiconductor lasers using n-type GaAs†

Abstract The spectral intensity distribution of the spontaneous omission from semiconductor lasers of n-type GaAs pumped by a 40 kv electron beam is calculated using the theory of recombination statistics. The results obtained are in good agreement with the published data on experiments carried out both at 77°k and 300°K. In particular a hump is obtained in the spectral distribution on the high energy side of the spectrum of the light emitted from n-type GaAs at 77°K when the level of doping is very high. This also is in agreement with the experimental observation reported elsewhere.

Doping dependence of the bulk quantum efficiency in electron-beam-excited n-type GaAs at 300°K†

Abstract The bulk quantum efficiency in electron-beam-pumped n-type GaAs at 300°K is studied as a function of the extent of impurity concentration. It is observed that this dependence is more or less similar in nature to the doping dependence of the internal quantum efficiency in electron-beam-excited n-typo GaAs at 77°K: as reported else where. The bulk quantum efficiency is found to remain independent of the extent of doping for donor concentrations less than 2 × 1017 cm−3 and sharply decreases with increasing doping beyond the donor concentration of 6 × 1017 cm−2. A maximum value of about 80° is noted to occur at a doping density of 6× 1017 cm−3