Compact Swept Near Infrared Light Source for Broadband Diffuse Optical Spectroscopic Imaging of Breast Malignancies

DESCRIPTION provided by applicant This project will develop swept wavelength laser light sources at several frequencies in the near infrared NIR While applicable to numerous applications the goal is to use these laser sources as an enabling technology for Diffuse Optical Spectroscopic Imaging DOSI a technique which allows noninvasive characterization of human tissue and can monitor and predict chemotherapy response in the treatment of breast cancer During this Phase II project the sources will be adapted to three specific wavelength ranges that are useful in detecting molecular states of the three most absorbent NIR tissue absorbers hemoglobin nm lipid nm and water nm The three light sources will be integrated into a miniature x mm NIR laser module for use in a handheld imaging system This is an enabling technology that will greatly expand technical capability and clinical applicability of optical imaging as well as the scientific knowledge that will result fro its incorporation into research studies The technology for the swept optical sources is based on a vertical cavity surface emitting laser VCSEL and a micro electro mechanical system MEMS that allows for wide tunability The devices require very low power to operate and the fabrication platform is robust low cost and adaptable to many applications Phase I of this project has already demonstrated a prototype swept laser source capable of mW output power and nm tuning range Phase II will improve upon these results to realize mW optical power and continuous tunability over nm which are practical requirements for a hand held DOSI system The swept NIR source will improve the performance and commercialization potential of a DOSI instrument by allowing D subsurface imaging improving the signal to noise ratio of the image by delivering a much higher photon intensity to the detector and allowing the miniaturization of the device so that it is compatible with routine clinical use Furthermore the unique spectral and performance characteristics of this laser open up a wide range of biomedical and other applications that can benefit from a miniaturized swept source PUBLIC HEALTH RELEVANCE This project will develop several new optical light sources that enable improved functional optical imaging of human tissue specifically for tissue hemoglobin fat and water concentration The new light sources will be integrated into a portable imaging system for breast cancer Key applications include differential diagnosis of breast cancer as well as monitoring and predicting the effectiveness of chemotherapy