FRODOSpec (Fibre-fed RObotic Dual-beam Optical Spectrograph) is a SRIF collaboration with the University of Southampton to develop a multi-purpose integral-field input spectrograph for the Liverpool Telescope. As the name implies it is a dual beam design with the beam split before the entrance to the individually optimized collimators. Two resolution options are available on each arm. With low resolution selected on each arm, the entire spectrum from the blue cutoff of the optical fibres (around 3800 Angstroms) to the red limit of the detectors at around 1 micron can be obtained in a single shot. The low resolution is implemented using conventional transmission gratings.
The higher resolution option for each arm is provided using a VPH grating bonded to a prism in order to throw the beam to the same angle as that obtained using the diffraction grating at low resolution. The central wavelengths in this configuration are fixed (centered around features of astrophysical interest).
The spectrograph is bench mounted on the observing floor of the telescope enclosure and is fed using a fibre bundle from the Cassegrain focus of the telescope. An integral field unit using a microlens input array feeds the fibre bundle.
Blue Arm LR: 3900-5700 (R=2600)
Blue Arm HR:> 3900-5100 (R=5500)
Red Arm LR: 5800-9400 (R=2200)
Red Arm HR: 5900-8000 (R=5300)
IFU Module:9.84''x9.84'' (12x12 lenslets each 0.82'')