MRI-R2: Development of Next-generation Imaging Spectrometer Based on a Tunable Liquid Crystal Filter

MRI-R2：基于可调谐液晶滤波器的下一代成像光谱仪的开发

• 批准号: 0960078
• 负责人: Joshua Semeter
• 金额: $ 77.5万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0960078&HistoricalAwards=false
• 关键词: MRI; R2; Development; Next; generation

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This research develops a solid state, frequency-agile, imaging spectrometer based on an electronically tunable optical filter. The instrument--referred to as the Liquid-Crystal (LC) Hyperspectral Imager (LCHSI)--solves the difficult problem of imaging transient events at multiple wavelengths simultaneously. At the heart of the LCHSI is a Fabry-Perot etalon whose transmission characteristic is controlled via an electric field applied across a liquid-crystal substrate injected into the gap. The substrate is etched into four electrically-isolated regions which may be individually controlled. The resulting quadrant filter is then coupled to beam diverting prisms to produce four narrow-band images on a single detector. Each channel may be individually tuned at millisecond cadence to thousands of narrow-band color combinations. The instrument thus combines the wavelength agility of a dispersion-based hyperspectral imager (HSI) with the imaging ability of a filter-wheel camera. This architecture has several advantages over competing multi-spectral and hyper-spectral systems. The combination of simultaneous multi-channel imaging and electronic tuning makes the LCHSI extremely versatile. The use of a single optical chain and a solid-state filter reduces size, mass, cost, and complexity. Static filters degrade over time resulting in a drift of their center wavelength, rendering them unusable; since an LC filter is tunable, it does not degrade, and need only be calibrated periodically. The LC filter is also extremely robust; the technology is thus a candidate for next-generation space-borne imaging systems.Although the applications of this technology are extremely broad, the initial demonstration of the LCHSI will be in the field of aeronomy, targeting five common emissions in the airglow and auroral spectrum: 427.8, 557.7, 630, 732 and 777.4 nm. The 732 and 777.4 lines can be tuned in a single quadrant, thus providing a test of the wavelength-hopping capability, as well as the on- and off-band sampling mode. Testing will be carried out at the NSF Upper Atmospheric Facilities at Arecibo, Puerto Rico, and Sondrestrom, Greenland.

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该研究开发了一种基于电子可调谐光学滤波器的固态，频率捷变，成像光谱仪。该仪器-被称为液晶（LC）高光谱成像仪（LCHSI）-解决了同时在多个波长下成像瞬态事件的难题。LCHSI的核心是Fabry-Perot标准具，其透射特性通过施加在注入到差距中的液晶衬底上的电场来控制。 衬底被蚀刻成可单独控制的四个电隔离区域。由此产生的四分之一过滤器，然后耦合到光束转向棱镜，以产生四个窄带图像在一个单一的检测器。 每个通道都可以以毫秒的节奏单独调谐到数千种窄带颜色组合。 因此，该仪器结合了基于色散的高光谱成像仪（HSI）的波长灵活性和滤光轮相机的成像能力。这种架构与竞争的多光谱和超光谱系统相比具有几个优点。同时多通道成像和电子调谐的结合使得LCHSI非常通用。使用单个光学链和固态滤波器减小了尺寸、质量、成本和复杂性。静态滤波器随时间退化，导致其中心波长漂移，使其不可用;由于LC滤波器是可调谐的，因此它不会退化，并且只需要定期校准。LC滤波器也非常耐用，因此该技术是下一代星载成像系统的候选技术。虽然该技术的应用非常广泛，但LCHSI的初步演示将在高空大气学领域进行，针对气辉和极光光谱中的五种常见发射：427.8，557.7，630，732和777.4 nm。732和777.4线可以在单个象限中调谐，从而提供波长跳变能力以及带内和带外采样模式的测试。 测试将在位于波多黎各的阿雷西博和格陵兰岛的松德斯特罗姆的NSF高层大气设施进行。