SBIR Phase I: Optical Mode Conversion for Chemical and Biological Sensing and Analysis

This Small Business Innovation Phase I research project proposes a novel diagnostic tool based upon evanescent field and complementary molecular vibrational spectroscopy methods for rapid detection and analysis of hazardous biological and chemical targets in solution and air. The main characteristic of the proposed approach is the use of evanescent field Surface Enhanced Raman Spectroscopy (SERS) and an active integrating probe with maximized evanescent field of propagating excitation signal created by controlled optical mode shifting in the active sensor region. The investigators propose to develop designs and fabrication methods for planar waveguide mechanisms to reversibly and controllably transfer photonic energy between optical modes within a specified path length. The sensor element will be attached to a Raman identification system to obtain Raman and fluorescence signals. The evanescent field at the sensor-environment interface will interact with biological and chemical molecules adsorbed onto or near the surface. Potential commercial applications of the proposed sensor system for environmental contamination include the possibility of contamination level observation in a large variety of remote locations by the use of fiber optic transmission or wireless network of sensor signals to analytical hardware; development of real-time monitoring equipment for hazardous industrial environments; detection of toxic industrial chemicals spills in commercial/industrial chemical storage and transport locations; and development of the real-time scanning system of the tap water contamination levels in residential and commercial buildings.