B. de Cremoux

Numerical simulation of the nonlinear response of a p-i-n photodiode under high illumination

A theoretical study and a model for the numerical simulation of the nonlinear electrical response, including the harmonic-generation rate calculation, of a p-i-n InGaAs photodiode under high-illumination conditions are discussed. The device structure is described. An algorithm, which is based on a finite-difference calculation, is used to calculate the temporal electrical response of the device to a microwave optical input signal. The different harmonics in the power spectrum are obtained using the fast Fourier transform (FFT) calculation. This model is a tool for designing the p-i-n photodiode and determining the conditions for its utilization in order to avoid the electrical response nonlinearity. >

Some characteristics of the GaAs/GaAlAs graded‐index separate‐confinement heterostructure quantum well laser structure

We describe the characteristics of graded‐index separate‐confinement heterostructure (GRIN‐SCH) quantum well laser structures for a wide range of quantum well thickness and graded layer composition. It was deduced that the ‘‘GRIN’’ region enhances carrier confinement and assists the thermalization of carriers into the quantum well. A maximum value of T0 of 190 K was measured for these single quantum well lasers.

1.54 μm room‐temperature electroluminescence of erbium‐doped GaAs and GaAlAs grown by molecular beam epitaxy

GaAs and GaAlAs double‐heterostructure light emitting diodes doped with erbium have been grown by molecular beam epitaxy. Both devices exhibit 1.54 μm electroluminescence (EL) at 300 K but the spectra obtained for GaAlAs:Er are much narrower than those of GaAs:Er. 1.54 μm EL has been detected for injection currents as low as 0.8 mA/cm2 and an external quantum efficiency of 10−6 has been found at 300 K. Preliminary data concerning the energy transfer from the injected carriers to the rare earth are provided.

cw operation of 1.57‐μm GaxIn1−xAsyP1−yInP distributed feedback lasers grown by low‐pressure metalorganic chemical vapor deposition

Continuous wave operation of 1.57‐μm distributed feedback lasers fabricated on material grown by two‐step low‐pressure metalorganic chemical vapor deposition growth process is reported for the first time. Room‐temperature continuous wave threshold currents as low as 60 mA have been measured for devices with cavity length of 300 μm and stripe width of 5 μm. Single longitudinal mode operation at fixed mode was obtained under the continuous wave condition, in the temperature range 9–90 °C, with the wavelength shift of 0.9 A/°C. A stop band of 25 A in which no resonance mode emission existed, was observed in the output spectrum of the distributed feedback laser.

cw phase‐locked array Ga0.25In0.75As0.5P0.5‐InP high power semiconductor laser grown by low‐pressure metalorganic chemical vapor deposition

Continuous and pulsed phase‐locked operation of a high power GaInAsP‐InP semiconductor laser emitting at 1.3 μm has been achieved. The laser consists of a seven‐striped array of ridge‐island lasers fabricated by a two‐step low‐pressure metalorganic chemical vapor deposition growth technique. Linear output powers greater than 300 mW (pulsed) and 120 mW (cw) have been obtained with no facet coatings. The far‐field full widths at half power, both parallel and perpendicular to the junction plane, were 3° and 45°, respectively, at 10 mW (at 20 °C) which is evidence for strong stripe‐to‐stripe coupling.

High yield manufacture of very low threshold, high reliability, 1.30-µm buried heterostructure laser diodes grown by metal organic chemical vapor deposition

We report the fabrication of very low threshold buried heterostructure lasers by a two-step MOCVD technique. We show very high yield of fabrication, very high uniformity of the initial characteristics, good reproducibility, and low degradation rate during the aging test.

Properties of 2D quantum well lasers

Abstract The lasing characteristics of quantum well and double heterostructure lasers are compared for the GaAs/GaAlAs and GaInAs/InP materials systems. The poorer performance of GaInAs/InP quantum well lasers is shown to be due to carrier heating linked to Auger recombination. However, low-temperature measurements reveal that in other respects these lasers are well behaved.

A low‐beam‐divergence cw (GaAl)As double‐heterostructure laser grown by low‐pressure metallorganic chemical vapor deposition process

We report the operation of a new stripe geometry (GaAl)As double‐heterostructure laser, grown by low‐pressure metallorganic vapor deposition (MO‐CVD). Several points make this MO‐CVD laser very suitable for optical communication: (i) a very low beam divergence in the direction perpendicular to the junction plane, 26 °; (ii) a low pulsed threshold current, 80 mA (stripe geometry: 5×300 μm); (iii) an emission wavelength of 8300 A (optimum for optical fiber transmission).

Low Drive Voltage GaAs Integrated Electrooptical Phase Modulator For The 10,6 Microns Wavelength

In this paper we describe a low drive voltage phase modulator for the 10,6 microns wavelength. We present also the experimental results that have been obtained with such a component and the related theoretical model. The wave-guiding basic structure is realized by the vapour phase epitaxy of a slightly N doped GaAs layer on a heavily N doped (100) substrate of the same material. An ohmic contact under the substrate and a planar Schottky electrode on the weakly doped medium permit the application of an electric field in the guiding region via a reverse polarization of the device. The experimental results we present show that the phase modulation we have mesured on the TE0 mode of the guide for different applied voltages proceeds from two effects. The first one is of course electrooptical and is due to the electric field which only exists in the depletion region lying under the Schottky electrode. The second one, which is not negligible because of the long working wavelength, comes from the refractive index increase due to the free electron density lowering in that depletion region. In the particular case of our experiments this last phenomenon leads to a drive voltage decrease : 80 volts for a phase-shift of π on the TE0 mode for a 16 mm long interaction instead of 100 volts without this depletion effect. The proposed theoretical model which takes into account these two contributions is in a good agreement with the experimental results and give the real possibility to predict the performances of such a device. In addition to these results related to the active aspect, we present a low loss wave-guiding planar configuration using a strongly N doped InP substrate where losses below 1 dB/cm on the TEO mode have been measured at the 10,6 microns wavelength.