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We theoretically investigate a dynamical regime, experimentally observed in monolithically integrated master oscillator power amplifiers emitting at 1.5 7 μm, consisting in large emission wavelength jumps of the device from the Bragg wavelength to that of the gain peak. Our analysis is based on numerical simulations by means of a travelling wave model that incorporates spatial effects such as spatial hole burning and coupled-cavity effects. Thermal effects are included by considering the optical response of the quantum well active medium within the quasi-equilibrium approximation at finite temperature, with a phenomenological description of the redshift of the gain peak and the changes in the background material refractive index by means of self- and cross-heating coefficients for both sections. We find that whereas the thermally-induced index changes are the responsible of the modal jumps between consecutive modes, the carrier-induced refractive index changes are the responsible of the jumps occurring between the Bragg wavelength and the gain peak.

High power (> 0.5 W) single-mode frequency laser at 1.55 μm are nowadays key components for a large number of applications such as lidar systems, telemetry or free-space communications. For this level of power, the most suitable and available sources are solid-state lasers and fiber lasers. Semiconductor devices, which are more compact and more efficient, have still to demonstrate very high power operation to be a credible competitor. In order to obtain these levels of power with semiconductor devices, the more suitable device seems to be the Master Oscillator Power Amplifier (MOPA). Single-mode emission is generated by a Distributed Feedback laser (DFB) and the signal is then amplified with a Power Amplifier (PA). To avoid complex optical coupling and to simplify the packaging, it is possible to integrate on the same chip the laser and the amplifier. The main challenges are the fabrication of the multi-section device (at least 2 sections: one for the laser and one for the amplifier) and the reduction of the reflections. Indeed the facet and the internal reflections can create multiple cavities behavior and disturb the laser single-mode emission. In this contribution, we report the realization of a 3-section monolithic MOPA on InP.

The beam properties of tapered semiconductor optical amplifiers emitting at 1.57 μm are analyzed by means of simulations with a self-consistent steady state electro-optical and thermal simulator. The results indicate that the self-focusing caused by carrier lensing is delayed to higher currents for devices with taper angle slightly higher than the free diffraction angle.

High brightness semiconductor lasers are potential transmitters for future space lidar systems. In the framework of the European Project BRITESPACE, we propose an all-semiconductor laser source for an Integrated Path Differential Absorption lidar system for column-averaged measurements of atmospheric CO2 in future satellite missions. The complete system architecture has to be adapted to the particular emission properties of these devices using a Random Modulated Continuous Wave approach. We present the initial experimental results of the InGaAsP/InP monolithic Master Oscillator Power Amplifiers, providing the ON and OFF wavelengths close to the selected absorption line around 1572 nm.

En el presente trabajo se propone un método para la medida y la estimación del error de la misma en la caracterización del factor de ensanchamiento de línea (parámetro α) de los láseres de semiconductor. La técnica propuesta se basa en el cálculo del parámetro α a partir de la medida de la intensidad y de la frecuencia instantánea de los pulsos generados por un laser de semiconductor conmutado en ganancia. El error de medida se estima mediante la comparación entre el espectro medido y el reconstruido utilizando los perfiles temporales de amplitud y fase de los pulsos generados. El método se ha aplicado a un laser DFB, obteniendo un error de medida menor del 5 %.

The optical and radio-frequency spectra of a monolithic master-oscillator power-amplifier emitting at 1.5 ?m have been analyzed in a wide range of steady-state injection conditions. The analysis of the spectral maps reveals that, under low injection current of the master oscillator, the device operates in two essentially different operation modes depending on the current injected into the amplifier section. The regular operation mode with predominance of the master oscillator alternates with lasing of the compound cavity modes allowed by the residual reflectance of the amplifier front facet. The quasi-periodic occurrence of these two regimes as a function of the amplifier current has been consistently interpreted in terms of a thermally tuned competition between the modes of the master oscillator and the compound cavity modes.

This paper presents the results obtained in the frame of an ESA-funded project called “Screening and Preevaluation of Shortwave Infrared Laser Diode for Space Application” with the objective of verifying the maturity of state of the art SWIR DFB lasers at 2.1µm to be used for space applications (mainly based on the occultation measurement principle and spectroscopy). The paper focus on the functional and environmental evaluation test plan. It includes high precision characterization, mechanical test (vibration and SRS shocks), thermal cycling, gamma and proton radiation tests, life test and some details of the Destructive Physical Analysis performed. The electro-optical characterization includes measurements of the tuning capabilities of the laser both by current and by temperature, the wavelength stability and the optical power versus laser current.