Photonic Crystal Mirrors make Smaller Surface-emmiting Lasers

Traditional surface-emitting lasers necessary for a high-speed optical links on microchips stand between 20 to 30 micrometers tall, dwarfing their silicon surroundings. However, by replacing bulky layers of dielectric reflectors necessary in the traditional laser design with two highly reflective photonic crystal mirrors, the lasers are shrunk down to a mere 2 micrometers. A single layer of the new photonic crystal, which is composed of compound semiconductor quantum well materials, is equal to about 15 to 30 layers of conventional dielectric reflectors. As a result manufactures can fabricate 2-micrometer-high lasers for data links that perform at speeds and efficiencies equal those in bulkier traditional designs. The researchers from University of Wisconsin-Madison and University of Texas Arlington who created the laser hope that it will help begin, “the co-existence of photonics with electronics on the chip level, [enabling] multi-functional energy-efficient super-chips.”