Basic Parameters

These REACH specifications are for IRD using single-mode fibers, combined with SCExAO. Please note that the specifications of IRD on the IRD website are for multi-mode fibers (MMF) combined with only AO188 (IRD MMF mode). The detectors and the laser comb specifications are common for REACH and IRD MMF mode.






Spectral Resulution


Spectral Coverage

0.97-1.75 um

Field of View

Each fiber accepts 40 mas at 1.6um Fiber-to-fiber distance is 200 mas Fibers can be positioned at any location in the high-contrast region (2 x 2 arcsec)


7 hexagonal packed single mode fibers (SMF) on the SCExAO focus. Light from a central fiber is fed to IRD’s SM. MCF output is connected to a photometric monitoring system.


See the above plot. Note that 1) this throughput was obtained under 0.6 arcsec seeing condition 2) 90%:10% beam splliter was used at the time of the observation, but this beam splitter will not be used for science observation. Therefore the expected throughput should be 10% better than this value.

Wavelength Calibration

Laser comb or ThAr lamp

Instrumental RV stability

At least 2 m/s when used with the laser comb. This is from a long-term stability test of IRD with a multi-mode fiber.

RV precision

Depending on spectral type of a star, usable spectral coverage, S/N of spectrum

Detector Noise

Read-out noise ~12 e- (10min. exposure)