Dispositivos emisores de luz para transmisión óptica de alta velocidad

Abstract

Silicon photonics is one of the technologies that has raised a higher interest during the last two decades. Therefore, the development of photonic integrated circuits has had an important presence in the research of new components and devices for the improvement of performance in optical communication systems. One of the main advantages of silicon photonics is its compatibility with CMOS electronic technology, which makes it a promising platform for mass production at low cost. The reduced size of photonic structures and the low propagation losses achieved in nanometric photonic waveguides has allowed the development of devices with a high density of integration. Similarly, high-speed optical modulators and highly efficient photodetectors have been demonstrated. However, the development of the light source or laser, an indispensable element in any optical communication system, is not possible due to the indirect bandgap of silicon. Therefore, other direct bandgap materials have been studied and proposed to integrate a laser on the silicon chip with emission in the O and C bands. The main challenge lies in reaching the coherent stimulated emission regime by means of an electric pump and in an efficient way. For this, several integration schemes have been proposed. Monolithic integration deals with the fabrication of the laser directly on the chip. On the other hand, hybrid integration consists in the fabrication of the laser separately to later be integrated into the chip. The best results have been achieved by means of this approach. Therefore, the main goal of the thesis has been the development of an external cavity laser by means of a hybrid integration scheme and with operation in the O-band. The different basic building blocks have been analyzed, designed, fabricated and experimentally demonstrated. Finally, the integration with the active material has been carried out, successfully demonstrating stimulated emission and single-mode operation. In addition, the thesis has also addressed the coupling to slow waveguide guidance structures, which have been proposed in monolithic integration schemes.