Tunable Birefringent Filters Using Liquid Crystal Elements

液晶技术的最新进展使得可以 构建在所述范围上操作的可调谐双折射滤波器 3500- 20，000埃，通带窄至100埃。 滤波器的中心波长可以电子地选择， 在几毫秒内，没有移动部件。 这些过滤器应该 生产成本相对较低（2 - 3 K美元）。 当液晶元件与固定的液晶元件串联放置时， 由双折射石英或方解石制成的延迟器，可以构造 具有较窄通带的滤波器，范围从30埃到 窄至0.25埃。 固定式减速器提供高 分辨率，而液晶执行调谐动作。 过滤器的结果是高度选择性和灵活性。 光学 这些仪器中的质量由固定延迟器确定， 并且对液晶只有轻微的限制 元素 在阶段I中，单个液晶元件的性能 被测量。 根据第二阶段的奖励，两个完整的过滤器 类型将建造和测试正在进行的太阳能和夜间- 时间节目

Recent advances in liquid crystal technology make it possible to construct tunable birefringent filters operating over the range 3500-20,000 Angstroms, with passbands as narrow as 100 Angstroms. The center wavelength of the filter can be selected electronically, in a few milliseconds, with no moving parts. These filters should be relatively inexpensive to produce ($2-3K). When liquid crystal elements are placed in series with fixed retarders made of birefringent quartz or calcite, one can construct filters with narrower passbands, ranging from 30 Angstroms to as narrow as 0.25 Angstroms. The fixed retarder provides the high resolution while the liquid crystal performs the tuning action. The filter that results is highly selective, and agile. Optical quality in these instruments is determined by the fixed retarders, and only mild restrictions are placed on the liquid crystal elements. In Phase I the performance of individual liquid crystal elements was measured. Under this Phase II award, complete filters of two types will be constructed and tested in ongoing solar and night- time programs.