TripleSpec

TripleSpec is a near-infrared spectrograph covering 0.095-2.46 μm, with a spectral resolution of 2500-to-2700. More than one has been built: one is installed on the Hale Telescope and another at the ARC 3.5m telescope at the Apache Point Observatory (APO). Cerro Tololo Inter-American Observatory's TripleSpec 4.1 (aka ARCoIRIS) is a follow-on. I believe it is called "TripleSpec" because after a grating spreads the infrared light by wavelength, it is passed through three prisms to disperse it in the crosswise direction.

TEDI (for TripleSpec Exoplanet Discovery Instrument or TripleSpec Externally Dispersed Interferometry) was an experiment consisting of incorporation of an externally dispersed interferometer (EDI), using interferometry techniques to detect the slight differences in the spectrum necessary to carry out the radial velocity method.