A porous silicon waveguide with integrated grating coupler is demonstrated as a new platform for portable detection of chemical and biological molecules. The two-layer porous silicon waveguide is formed by electrochemical etching and a photoresist grating is fabricated directly on the waveguide core by means of electron beam lithography. Angle-resolved reflectance measurements reveal distinct peaks corresponding to the guided mode. A 0.420° reflectance shift was observed upon 16-base DNA hybridization, which was more than a factor of 5 larger than the observed reflectance shift after exposure to a mismatched DNA sequence.© (2009) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Xing Wei ; Christopher Kang ; Guoguang Rong ; Scott T. Retterer and Sharon M. Weiss
"Porous silicon waveguide with integrated grating coupler for DNA sensing", Proc. SPIE 7167, Frontiers in Pathogen Detection: From Nanosensors to Systems, 71670C (February 1, 2009); doi:10.1117/12.809239; http://dx.doi.org/10.1117/12.809239