Design and performance of a MEMS-based infrared multi-object spectrometer

The Infrared Multi-Object Spectrometer (IRMOS) is an innovative near-IR instrument employing an array of MEMS micro mirrors for focal plane target selection. IRMOS is a joint project of the Space Telescope Science Institute, the NASA James Webb Space Telescope, and the Kitt Peak National Observatory and will shortly become available to the community at Kitt Peak. IRMOS uses a Texas Instruments 848x600 element DMD as a micro mirror array to synthesize slits to obtain up to 100 simultaneous spectra. It provides R~300, 1000, and 3000 spectroscopy in the J, H, and K bands plus R~1000 in Z together with imaging in all bands. Designed for the KPNO 4 and 2.1-meter telescopes, IRMOS will provide 3x2 and 6x4 arc minute fields of view on these telescopes. We describe the design and status of IRMOS, summarize its expected performance, and present early test data from system level lab tests.