Diffraction Limited Integral Field Spectrographs for Large Telescopes

As telescopes become larger and adaptive optics systems become more capable, integral field spectrographs offer a range of advantages over traditional cameras and spectrographs for many applications. I'll specifically discuss the design and benefits of lenslet-based integral field spectrographs with examples from the OSIRIS instrument at Keck, the Gemini Planet Imager IFS and the IRIS instrument for the planned Thirty Meter Telescope. All three of these spectrographs are fully cryogenic with minimal wavefront error, high throughput and relatively large fields of view (in terms of the number of spatial elements).