Long term monitoring is needed to track changes in the chemical composition of the atmosphere that may contribute to environmental degradation and human health problems. Instruments currently used to measure solar radiation use classical optical radiometric components which are expensive, bulky and fragile. This project is to design, fabricate and test a new high resolution multi-channel spectrometer based on a novel cascaded tunable holographic filter (CTHF) that will be rugged, compact and lightweight, will operate at low power, and will contain no moving parts. The proposed CTHF will consist of two cascaded components: a coarse filter to select the desired portion of the spectrum and a fine, high resolution tunable bandpass filter operating within the selected range at any arbitrary wavelength. A proof-of-concept CTHF prototype will be designed, fabricated and demonstrated in Phase I. This will include modification of the existing technology for the visible range of the optical spectrum into the near infrared (NIR) range and extension of proprietary photopolymer processing. In Phase II, the CTHF will be incorporated in the design and fabrication of a novel NIR instrument to be used in the Department of Energy's atmospheric measurement research program.
Commercial Applications and Other Benefits as described by the awardee:The use of a novel CTHF based instrument will expand the present capabilities for solar spectral radiance, infrared spectral radiance and transmittance measurements. The resulting instrument can be used for a wide variety of optical sensing applications and spectroscopy ranging from atmospheric measurement, biology and medicine, to Doppler lidar.
