MONOLITHICALLY INTEGRATED NANOWIRE LASERS ON SILICON
The increasing demand for higher data processing speeds and the minimization of the energy costs per bit are main challenges in the fields of computer science and communication. In order to exploit the high data rates and low-energy consumption provided by optical communication on a microchip level, powerful light sources seamlessly integrated with electrical circuits are urgently needed. However, the intrinsic inability of silicon to efficiently emit light in combination with the incompatibility of active laser materials with silicon microchips demands for novel strategies to enable chip-scale optical communication.
The presented innovation uses III-V nanowires that allow the monolithic integration of laser materials on silicon whilst providing excellent material quality. The patented geometry allows light recirculation in the nanowires and thus enables laser emission from monolithically integrated devices on microchips. Furthermore, the invention could allow to shift the production of conventional semiconductor lasers to the silicon platform and thus enable a dramatic reduction of laser diode fabrication costs. The present invention consists overall of a new structure of an on-chip nanowire laser device, in which a tailored dielectric interlayer is inserted at the NW-Silicon interface to enable lasing operation. Based on that, low-threshold lasing and single mode operation can be achieved. The device allows charge carrier injection directly via the silicon substrate and can be seamlessly integrated with microchip electronics.
This innovation opens the possibility for the efficient integration of lasers on silicon platforms. The fabrication of nanowire laser arrays on 8” and 12” silicon wafers would allow a dramatic reduction of the production cost of laser diodes. Integrated on microchips, the innovation opens the door to chip-scale optical communication allowing strongly increased computation speeds and a reduced energy consumption of digital devices.
Device operation under optical excitation has been demonstrated. The coupling of optical pumped nanowire lasers to silicon was achieved. Pulsed operation of optically pumped nanowire lasers up to 200 GHz was measured. The invention is being currently further developed in order to achieve electrically driven laser operation.
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