Photonic device and method of making same using nanowires

A photonic device comprising:

• a first layer of a microcrystalline material on a substrate surface;
• a second layer of a microcrystalline material on the substrate surface horizontally spaced from the first layer by a gap;
• and
• a nano-scale antireflector in the gap between the first layer and the second layer, the nano-scale antireflector being light absorptive both in a wide band of optical frequencies and over a wide range of incident angles, such that negligible light is reflected from the gap;
• wherein the nano-scale antireflector comprises a bramble of nanowires, the bramble comprising a plurality of randomly oriented nanowires having first ends integral to crystallites in each of the first layer and the second layer, the nanowires of the bramble extending into the gap from the first layer and the second layer.

A method of making a photonic device comprising:

• providing a first layer of a microcrystalline material on a substrate surface;
• providing a second layer of a microcrystalline material on a substrate surface horizontally spaced from the first layer by a gap;
• and
• forming a bramble of nanowires between the first layer and the second layer, the nanowires of the bramble having first ends integral to crystallites in each of the first layer and the second layer, such that the nanowires of the bramble extend into the gap from opposing directions.