Recently, AlGaInAs-silicon evanescent lasers have been demonstrated as a method of integrating active photonic devices on a silicon based platform. This hybrid waveguide architecture consists of III-V quantum wells bonded to silicon waveguides. The self aligned optical mode leads to a bonding process that is manufacturable in high volumes. Here give an overview of a racetrack resonator laser integrated with two photo-detectors on the hybrid AlGaInAs-silicon evanescent device platform. Unlike previous demonstrations of hybrid AlGaInAs-silicon evanescent lasers, we demonstrate an on-chip racetrack resonator laser that does not rely on facet polishing and dicing in order to define the laser cavity. The laser runs continuous-wave (c.w.) at 1590 nm with a threshold of 175 mA, has a maximum total output power of 29 mW and a maximum operating temperature of 60 C. The output of this laser light is directly coupled into a pair of on chip hybrid AlGaInAs-silicon evanescent photodetectors used to measure the laser output.Keywords: Silicon evanescent laser, Silicon photonics, integration, photodetector, semiconductor laser
IntroductionSilicon photonics has received a lot of attention by researchers with the hopes to leverage the low cost manufacturing infrastructure of CMOS photonics for applications such as chip to chip and board to board interconnects [1][2][3][4]. This work has been focused on the building blocks of photonic communication systems such as lasers [5][6][7][8], modulators, photodetectors, and others [9][10][11][12][13][14][15]. Our work has been focused on developing a hybrid integration platform that allows for III-V material functionality, such as light amplification and detection, to be utilized on silicon waveguide based devices. This platform consists of a III-V epitaxial structure bonded to a silicon waveguide to make a hybrid waveguide such that its optical mode lies primarily in the silicon region with a small portion of the mode overlapping the quantum wells of the III-V structure for optical gain. The optical mode characteristics are predominately defined by the silicon waveguide processing. Bonding can be performed without critical alignment. The remaining critical alignment steps, such as the definition of electrical current injection channels, utilize standard lithographic techniques leading to a high volume, low cost, solution for active devices on silicon. The first hybrid laser demonstration relied on the dicing and polishing of straight hybrid waveguides to define a Fabry-Perot laser cavity [16]. Here we review a monolithic hybrid AlGaInAs silicon evanescent laser based on a racetrack-resonator-topography. The laser runs continuous-wave (c.w.) with a threshold of 175 mA, a maximum total output power of 29 mW and maximum operating temperature of 60 oC. Moreover we report the integration of this laser with a hybrid AlGaInAs-silicon evanescent photodetector used to measure the laser output [17].