Bio-inspired thin and flat solar concentrator for efficient, wide acceptance angle light collection

We present a novel thin and flat solar concentrator design, inspired by the structure and optical functionality of the ommatidium in the compound eye of insects. By combining a microlens with a curved light guide, rather than the conventionally employed dielectric or metallic reflectors, we could simultaneously achieve low-loss light redirection and wide acceptance angle without compromising the overall thinness or flatness of the concentrator. Through design optimizations, we could achieve optical concentration factors up to 39 and acceptance angle up to ±15° while maintaining the thickness of the concentrator under 1.1 cm for a length of 20 cm. We also showed that the optical concentration factor can be further increased to 81 through tapering of the geometry.