Micro-metalens array to enhance the fill factor of a focal plane array

Abstract

Abstract

Abstract Concentrator microlens arrays are widely used to improve the performance of optoelectronic detectors with small fill factors and the signal-to-noise ratio of focal plane arrays (FPAs). However, conventional refractive microlenses rely on surface profiles to modulate the optical field, and their fabrication is incompatible with standard semiconductor manufacturing processes. Metasurface-based devices, which manipulate light via nanostructures, are planar, provide multiple degrees of freedom for light modulation, and are compatible with semiconductor fabrication.For InGaAs/InP infrared detectors, we propose micro-metalens arrays (MMLAs) to replace conventional microlens arrays in this article. A solid-immersion design scheme is applied to typical pn-type and PIN-type detectors to improve the energy utilization efficiency of FPAs. Simulated results indicate that the equivalent fill factor of the solid-immersion MMLA-integrated FPA is improved by an average factor of 6.21 and 6.46 for the pn-type and PIN-type detectors, respectively. Therefore, the enhanced energy collection substantially improves the signal-to-noise ratio (SNR) of an infrared detector. This approach is significant for the improvement of performance and fabrication process in advanced infrared detection.