SYSTEMS, METHODS, AND APPARATUS FOR SENSITIVE THERMAL IMAGING

摘要

The high-pixel-count uncooled thermal imaging arrays disclosed herein have liquid crystal (LC) microcavity transducers separate from the read-out integrated circuit (ROIC). The transducer converts incident infrared (IR) radiation in birefringence changes that can be measured with visible light. In other words, the system uses the temperature sensitivity of the LC birefringence to convert the IR scene to a visible image. Measurements on sample arrays indicate that the LC material quality is similar to that of bulk samples and has good noise performance. Additionally, high-fill-factor arrays on fused-silica substrates may be processed to enable optimization of conditions for greatly improved temperature sensitivity. An additional IR absorber layer may be integrated into the process to tune the structure for the infrared.

主权项

1. A system for detecting incident infrared radiation, the system comprising:
a liquid crystal transducer having a birefringence Γ that varies as a function of the incident infrared radiation; a visible light source, in optical communication with the liquid crystal transducer, to illuminate the liquid crystal transducer with a first beam of linearly polarized visible light so as to produce a beam of elliptically polarized visible light having a degree of ellipticity that varies in proportion to the birefringence of the array of liquid crystal cells, the first beam of linearly polarized light having a polarization angle of 45° with respect to a fast axis of the liquid crystal transducer; a quarter-wave plate, in optical communication with the liquid crystal transducer, to convert the beam of elliptically polarized visible light into a second beam of linearly polarized visible light, the quarter-wave plate having an optical axis aligned with the polarization angle of the first beam of linearly polarized light; an analyzer, in optical communication with the quarter-wave plate, to polarize the second beam of linearly polarized visible at an angle based on the birefringence Γ of the liquid crystal transducer; and a detector array, in optical communication with the analyzer, to produce an electronic representation of the incident infrared radiation in response to detection of the second beam of linearly polarized visible light.