Innovative Multiband Filters

用于天文成像的滤光片通常或多或少均匀地接纳两个极端波长之间的所有光线。然而，在某些情况下，更复杂的传输函数是非常可取的。其中一个例子是在近红外波段，由氢氧根分子产生的地球大气辐射出现在窄波段。在这里，如果分子线可以被选择性地阻断，那么用宽带滤波器成像的背景可以减少两倍。直到最近，自定义“调优”过滤器还是不可能的。然而，它现在不仅是实用的，而且是提高近红外调查速度的一种引人注目的技术。与其他提高效率的方法相比，有充分的理由相信这种创新的成像滤光片也应该是便宜的。亚利桑那州立大学的James Rhoads提议进行定制红外成像滤光片的开发，与商业供应商合作设计和表征各种天文学应用。在这些研究领域中，将会看到质量上的好处：a)发现最早的星系和类星体，b)发现高红移超新星并表征暗能量，以及c)通过开发一种特殊的过滤器来识别质量最低的褐矮星，这种过滤器调整到独特的近红外光谱。PI将监督这些滤光片的设计、建造和评估，此外还将为国家光学天文台的公众仪器提供功能光学。此外，过滤器的处方将被整个观测天文学界公布以供复制。这项工作的资金由美国国家科学基金会天文科学部通过其先进技术和仪器项目提供。

Filters for astronomical imaging have typically admitted more or less uniformly all of the light between two wavelength extremes. However, there are instances where more complex transmission functions are highly desirable. One such case is in the near-infrared, where terrestrial atmospheric emission arising from the molecule OH occurs in narrow bands. Here, the background for imaging with a broadband filter could be reduced by a factor of two if the molecular lines could be selectively blocked. Until recently, custom "tuning" of filters was not possible. However, it is now not only practical but also a compelling technique for improving the speed of near-IR surveys. Compared to other methods of enhancing efficiency, there is every reason to believe that such innovative imaging filters should also be inexpensive.Dr. James Rhoads of the Arizona State University proposes to carry out the development of custom infrared imaging filters, working with commercial vendors in their design and characterization for a variety of applications in astronomy. Among the research areas that will see a qualitative benefit are a) finding the earliest galaxies and quasars, b) discovering high-redshift supernovae and characterizing dark energy, and c) identifying the lowest-mass brown dwarfs through the development of a special filter tuned to its unique near-IR spectrum. The PI will oversee the design, construction, and evaluation of these filters, and in addition provide functioning optics for use by the public on instruments operated at the National Optical Astronomy Observatories. Furthermore, the filter prescriptions will be publicized for duplication by the entire observational astronomy community. Funding for this work is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.