Visible-IR AOTF Spectrometer for Hyperspectral Imaging in SpaceBased Application

Brimrose proposes to develop a miniaturized, light weight acousto-optic tunable filter spectrometer for hyperspectral imaging in the visible-infrared wavelength range (500 - 2200 nm) that is capable of withstanding the harsh environment of space. AOTF spectrometers have several advantages over traditional spectrometers including the absence of moving component, high throughput and resolution and their extremely fast scanning capabilities. However, standard AOTF devices are unable to withstand the low temperatures that would be encountered in space based applications. We have developed a novel transducer engagement technique that enables the low temperature capability of the AOTF spectrometer. Using this technique, we have constructed an AOTF that has been successfully cycled from room temperature down to 77K with no signs of failure and can hold against accelerations over 200g. The device performance, including diffraction efficiency and spectral resolution, is found comparable to that of a metal-bonded device. In phase I of this project, Brimrose will optimize our novel technique, build a visible-IR AOTF device and demonstrate its operation with a single detector. In phase II, we will demonstrate the use of the AOTF in a hyper-spectral imaging system with detector array and optimize the device for use in such systems.