Compact Optical Sensing Systems
Conferences & Talks

• Joerg Martini

Stanford University

20 April 2011
4:15pm

description

PARC develops various different compact optical detection systems, including our concept for a small wavelength shift detector. It is capable of measuring shifts in wavelength peaks with sub-pm resolution, by differential light detection through a linear variable filter. This can be used for example for the interrogation of Fiber-Bragg sensors.

Biomedical applications of sensors include our approach to realize a long term implantable optical glucose sensor. It is based on refractive index (RI) measurements in a miniaturized double chamber Fabry-Perot etalon that measures the differential RI between a reference chamber and a measurement chamber. The RI difference can be made specific to glucose by competitively and reversibly releasing dextran from immobilized Concanavalin A.

For point-of-need applications we have developed a robust and inexpensive microfluidic particle detector. The enabling technique is termed “spatially modulated emission” and generates a time-dependent signal as a continuously fluorescing (bio-)particle traverses a optical transmission pattern. Correlating the detected signal with the known pattern achieves high discrimination of the particle signal from background noise.