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 (0.95 to 2.5 microns). Being diffraction limited allows for a compact, stable and thus cost-effective design. HISPEC will be built for the Keck II telescope and fed by the KPIC fiber injection unit. 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 EPRV, transit spectroscopy, direct spectroscopy, BD characterization, stellar physics/chemistry, disk kinematics/composition, and extragalactic science.

Parameters Specifications Notes
Wavelength coverage y to K (0.95 to 2.5 microns) Simultaneous
Resolving power (R) 100,000 On average
Instrumental stability 30 cm/s Goal: 10 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 14-15 mag S/N=30 per resel in 1 hour
Point Source sensitivity on TMT 17-19 mag S/N=30 per resel in 1 hour
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