Proto-IRHS with Cooled Germanium Immersion Grating

Proto-type IRHS (Mid-Infrared High Dispersion Spectrograph) is a Littrow mount echelle spectrometer for 8 to 13 μm wavelength region (N band), where rich silicate band and numerous vibration mode of organic functional groups exist. Maximum resolving power is 50,000 at 10 μm with slit width of 0.612 arcseconds (0.48 mm) and two pixels per resolution element. The slit width is equal to diffraction-limited spot size of the point source. Size of immersion grating is about 30×30×72 μm, which is the quarter size of full-spec IRHS immersion grating. Proto-type IRHS uses two focal plane array detectors; Si:As IBC (512×412 pixels, unit pixel size 30 μm) for echelle spectrograph and InSb (256×256 pixels, unit pixel size 30 μm) for slit viewer and Lyot-stop viewer.





Bird view layout of Proto-type IRHS optics
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Optical plate

Germanium Immersion Grating (30×30×72 μm)
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Si:As IBC (512×412 pixels, unit pixel size 30 μm) for echelle spectrograph

InSb (256×256 pixels, unit pixel size 30 μm) for slit viewer and Lyot-stop viewer
Specification (in Japanese)
Summary of Recent Experimental Results
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