Photonic devices based on preferential etching

We introduce a design concept of optical waveguides characterized by a practical and reproducible process based on preferential etching of crystalline silicon substrates. Low-loss waveguides, spot-size converters, and power dividers have been obtained with polymers. We have also aligned liquid crystals in the waveguides and demonstrated guided propagation. Therefore this technology is a suitable platform for soft-matter photonics and heterogeneous integration.