Small solutions to the large telescope problem: a massively replicated MEMS spectrograph

Abstract

In traditional seeing-limited observations the spectrograph aperture scales with telescope aperture, driving sizes and costs to enormous proportions. We propose a new solution to the seeing-limited spectrograph problem. A massively fiber-sliced configuration feeds a set of small diffraction-limited spectrographs. We present a prototype, tunable, J-band, diffraction grating, designed specifically for Astronomical applications: The grating sits at the heart of a spectrograph, no bigger than a few inches on a side. Throughput requirements dictate using tens-ofthousands of spectrographs on a single 10 to 30 meter telescope. A full system would cost significantly less than typical instruments on 10m or 30m telescopes.

Smart instrument technologies to meet extreme instrument stability requirements

“…Secondly, we propose development of better active devices and techniques to control residual errors. A more radical future solution is to use photonics technology and fibre feeds to reduce dramatically the size of spectrographs by massive multiplexing [19] [20] .…”