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J.T. Stocke, B.A. Keeney (CASA, Univ. of Colorado), D.K. Yang (Liquid Crystal Inst., Kent St. Univ.)
Presently, simultaneous spectroscopic observation of multiple objects requires much planning and painstaking care, typically involving a preliminary imaging observation to select sources, precision drilling of metal plates, and human intervention to place the masks in the focal plane. Envisioning an automated alternative, we are developing a device that incorporates 'scattering' liquid crystal devices (LCDs) as computer-operated focal plane apertures for multiobject spectroscopy. We are currently testing a 116x116, 250 micron square pixel device which has <1% throughput when no voltage is applied and >80% throughput longward of 400 nm when voltage is applied. Thus, sources can be selected for multiobject spectroscopy immediately after an image of the target field is taken, and one can obtain spectra of multiple objects in real time by creating slits in the proper positions on the LCD. Lab testing has shown that, for currently available LCDs, in order to get an acceptable contrast ratio between the clear and opaque states of the LCD, two screens must be stacked on top of each other to reduce the transmission in the opaque state.
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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.