Waveguide-coupled nanopillar metal-cavity light-emitting diodes on silicon

Abstract

Nanoscale light sources using metal cavities have been proposed to enable high integration density, efficient operation at low energy per bit and ultra-fast modulation, which would make them attractive for future low-power optical interconnects. For this application, such devices are required to be efficient, waveguide-coupled and integrated on a silicon substrate. We demonstrate a metal-cavity light-emitting diode coupled to a waveguide on silicon. The cavity consists of a metal-coated III–V semiconductor nanopillar which funnels a large fraction of spontaneous emission into the fundamental mode of an InP waveguide bonded to a silicon wafer showing full compatibility with membrane-on-Si photonic integration platforms. The device was characterized through a grating coupler and shows on-chip external quantum efficiency in the 10−4–10−2 range at tens of microamp current injection levels, which greatly exceeds the performance of any waveguide-coupled nanoscale light source integrated on silicon in this current range. Furthermore, direct modulation experiments reveal sub-nanosecond electro-optical response with the potential for multi gigabit per second modulation speeds.

Purcell Effect in the Stimulated and Spontaneous Emission Rates of Nanoscale Semiconductor Lasers

“…2 the calculated L − I curves are displayed showing the optical power versus the injected current. The curves were simulated for the following values of surface recombination: υ s = 7×10 4 cm/s (dash-dot black trace), a typical value found in micro-and nanopillar devices [14], [58], and υ s = 260 cm/s (solid blue trace), an ultralow value of surface recombination achieved recently in InGaAs/InP nanopillars using an improved passivation method [69]. In all plots, we kept a realistic room-temperature Auger coefficient (see Table I).…”

Circuit designs for superconducting optoelectronic loop neurons

“…System efficiency can be gained with improved drive circuits, low-capacitance light sources, and high efficiency light sources. Lowtemperature-operation is extremely beneficial for increasing LED internal quantum efficiency [43]. We assume LEDs with 10 fF capacitance and 10 −3 quantum efficiency can be achieved, and even better performance is likely attainable [43].…”

“…The ability to produce light at multiple frequencies may also be advantageous to enable different colors to be routed on the same waveguides to perform different synaptic operations (i.e., firing versus update). Compound semiconductors have these spectral and temporal properties, and they can be integrated with silicon waveguides [43] with high efficiency, particularly at cryogenic temperature. Yet cryogenic operation enables several types of silicon light sources [42,47,48], which bring the advantage of simpler process integration.…”

The Largest Cognitive Systems Will be Optoelectronic

“…To operate at liquid helium temperature, 4.2 K, approximately one kilowatt of cooling power is required for each watt of device power. Cryogenic operation of sources can gain two orders of magnitude in efficiency [67]. Similarly, low-temperature waveguide-integrated superconducting detectors efficiently receive single photons, while room-temperature waveguide-integrated, scalable semiconductor photodetectors may require one thousand photons or more.…”