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ET Lab Home  /  Instruments  /  HISPEC

High resolution Infrared Spectrograph for Exoplanet Characterization

HISPEC is a diffraction-limited, fiber-fed high-resolution infrared spectrograph covering the y to K band spectral range in one shot (0.98 to 2.46 microns). Being diffraction limited allows for a compact and stable design. HISPEC is being built for the Keck II telescope and fed by the upgraded Keck II AO system (project HAKA). HISPEC's first light at Keck Observatory is slated for 2026. HISPEC will be the workhorse high-resolution infrared spectrograph of TMT soon after first light, as part of the MODHIS facility, which includes a new fiber injection unit designed to integrate NFIRAOS the first light adaptive optics system of TMT. The scientific scope of HISPEC/MODHIS is very broad and ranges from exoplanet IR PRV, transit spectroscopy, direct spectroscopy, BD characterization, stellar physics/chemistry, disk kinematics/composition, and extragalactic science.

Parameters Specifications Notes
Wavelength coverage y to K (0.98 to 2.46 microns) Simultaneous
Resolving power (R) 100,000 On average
Instrumental stability 30 cm/s Excludes atmosphere
Calibration Laser Frequency Comb, Fabry-Perot Etalon Gas cells for absolute reference
Design approach Diffraction-limited Single mode
Feed Single-mode fibers, photonic lanterns Modest multiplexing (TBD)
End-to-End efficiency >5% Goal: >10%
Sampling >2.5 pixel Over 80% of the range
Point Source sensitivity on Keck 15 mag S/N=30 per resel in 4 hours
Point Source sensitivity on TMT ~19 mag S/N=30 per resel in 4 hours
Mode 1 Single or multi-object Photonic lantern or single-mode fibers
Mode 2 High-contrast off-axis High Dispersion Coronagraphy
Mode 3 High-contrast on-axis Vortex Fiber Nulling