Improved Control Electronics for OSIRIS-GTC Commercial Tunable Filters

摘要

OSIRIS (Optical System for Imaging and low/intermediate - Resolution Integrated Spectroscopy) is an instrument designed to obtain images and low - resolution spectra of astronomical objects in the optical domain (from 365 to 1000 nm). It will be installed on Day One at the Nasmyth focus of the 10 m Spanish GTC Telescope. One of its key elements is two ICOS ET100 tunable filters, which will be used for several scientific programs. ICOS delivered the CS100 controller, a standard controller for these devices. This controller has several specifications that do not satisfy our project requirements. A plug-in electronic module for the CS100 controller is being developed at IAC to address these issues. The main features of this improved module are: capability to scan the full range of the etalon from a remote host, an improved resolution >15 bits, a table to store a pre-defined set of cavity spacing points allowing quicker gap spacing change, and the possibility of synchronizing that change with an external trigger signal. Currently, an initial prototype has been developed and is operating successfully. The control electronics are based upon a microcontroller embedded in a FPGA. We have started the detailed design of the final product, whose completion and testing is expected by the end of 2005.