Microbolometer

Abstract: Uncooled infrared bolometer arrays have become the technology of choice for low-cost infrared imaging systems used in applications such as thermography, firefighting, driver night vision, security and surveillance. Uncooled infrared bolometer arrays are reaching performance levels which previously only were possible with cooled infrared photon detectors. With a continuously increasing market volume (> 100 000 units per year to date), the cost for uncooled infrared imaging chips are decreasing accordingly. In this paper we give an overview of the historical development of uncooled infrared bolometer technology and present the most important bolometer performance parameters. The different technology concepts, bolometer design approaches and bolometer materials (including vanadium oxide, amorphous silicon, silicon diodes, silicon-germanium and metals) are discussed in detail. This is followed by an analysis of the current state-of-the-art infrared bolometer technologies, the status of the infrared industry and the latest technology trends.

Abstract: A monolithically constructed infrared, tunable Fabry-Perot cavity filter-detector for spectroscopic detection of particular substances having an absorption line in the wavelength range from 2 to 12 microns. The filter-detector has a hermetically sealed Fabry-Perot cavity that has a mirror which has an adjustable distance relative to another mirror of the cavity. The former mirror is adjusted by piezoelectric film on the mirror support or with piezoelectric stacks or wall supporting the mirror. There may be electrodes situated near the mirrors for capacitive sensing of the distance between the mirrors. Light to be filtered and detected comes in through a window wafer which may have diffractive or refractive microlenses, plus an optional spatial filter. After passing through the window wafer, the light is filtered by the tunable mirrors of the Fabry-Perot cavity. The portion of the light that is passed by the cavity is detected by an infrared microbolometer or a CCD array. The cavity and detector are hermetically sealed in a vacuum.

Abstract: The present invention generally provides a terahertz (THz) imaging system that includes a source for generating radiation (e.g., a quantum cascade laser) having one or more frequencies in a range of about 0.1 THz to about 10 THz, and a two-dimensional detector array comprising a plurality of radiation detecting elements that are capable of detecting radiation in that frequency range. An optical system directs radiation from the source to an object to be imaged. The detector array detects at least a portion of the radiation transmitted through the object (or reflected by the object) so as to form a THz image of that object.

Abstract: Historical overview, G. Buser and M.F. Tompsett principles of uncooled infrared focal plane arrays, P.W. Kruse monolithic silicon resistive microbolometer arrays, A. Wood hybrid pyroelectric/ferroelectric bolometer arrays, C. Hanson monolithic pyroelectric bolometer arrays, D.L. Polla and J.R. Choi thermoelectric uncooled infrared focal plane array, N. Teranishi pyroelectric vidicon, M.F. Tompsett tunnelling infrared sensors, T.W. Kenny application of quartz microresonators to uncooled IR imaging arrays, J.R. Vig, R.L. Filler and Y. Kim.