Freestanding waveguides in silicon

Using a direct-write process for the production of three dimensional microstructures on a semiconductor, freestanding waveguides have been realized in silicon. The waveguides are produced by a focused beam of high energy protons that is scanned over a silicon substrate. The latent image of the scan is subsequently developed by electrochemical etching. Herein the authors report on the fabrication method as well as determining the propagation loss of these structures. Propagation loss values of 13.4 and 14.6 dB/cm were obtained for these preliminary structures for transverse electric and transverse magnetic polarizations, respectively. (c) 2007 American Institute of Physics.