Preliminary optical design for the TMT mid-infrared adaptive optics system and echelle spectrograph

We present a preliminary optical design for a mid-infrared, high-resolution spectrograph (MIRES), together with an integrated adaptive optics system optimized for the mid-infrared, intended for use on a 30-meter telescope. The design includes laser guide star wavefront sensors, a near-infrared natural guide star wavefront sensor with a patrol field of 60 arcseconds, and near-infrared and mid-infrared imaging channels, in addition to the cross-dispersed spectrograph itself. The spectrograph provides resolution of up to 120,000 and continuous spectral coverage over multiple cross-dispersed orders, with high efficiency between 4.5 and 25 microns.