Doubly Multiplexed Dispersive Spectrometers

We analyze the performance of a dispersion instrument in which light is multiplexed both in the entrance and exit slit positions. This double multiplexing scheme allows one to recover both Fellgett's advantage and the high throughput advantage normally attributed only to interferometric spectrometers. The spectrometer's performance is evaluated for a number of binary cyclic coding schemes. Optical limitations on doubly multiplexed instruments are discussed, and we show that such spectrometers compare favorably with Michelson interferometric spectrometers. Some first results obtained with a laboratory pilot model are presented.