Monolithic master oscillator power amplifier at 1.58 µm for lidar measurements

Nowadays the interest in high power semiconductor devices is growing for applications such as telemetry, lidar system or free space communications. Indeed semiconductor devices can be an alternative to solid state lasers because they are more compact and less power consuming. These characteristics are very important for constrained and/or low power supply environment such as airplanes or satellites. Lots of work has been done in the 800-1200 nm range for integrated and free space Master Oscillator Power Amplifier (MOPA) [1]-[3]. At 1.5 ?m, the only commercially available MOPA is from QPC [4]: the fibred output power is about 700 mW and the optical linewidth is 500 kHz. In this paper, we first report on the simulations we have done to determine the appropriate vertical structure and architecture for a good MOPA at 1.58 ?m (section II). Then we describe the fabrication of the devices (section III). Finally we report on the optical and electrical measurements we have done for various devices (section IV)

All-semiconductor master oscillator power amplifier at 1.5 um for high power applications

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