AIV of FRIDA optics: from optical manufacturing to system cryogenic qualification

FRIDA is an infrared (0.9-2.5 mu m) imager and integral-field spectrograph that will work in concert with the Gran Telescopio Canarias Adaptive Optics system (GTCAO). It is a diffraction-limited and cryogenic instrument. The imag-equality requirements for the complete system (SR>0.9 for K band) necessitate high precision manufacturing and quality control for all the optical components, subsystems and the complete system. Additionally, FRIDA will use coronagraphic masks for high-contrast imaging. This also requires very low roughness of the polished surfaces (< 2 nm RMS) and high quality AR coatings. To comply with the stringent image-quality requirements, we manufactured and tested the main optical and mechanical components in our workshops in Mexico. Also we assembled and aligned each subsystem and performed interferometric tests to validate them at room temperature. Furthermore, the complete instrument was assembled, tested and validated at room temperature and at 1.06 microns wavelength on a prototype of the cold bench. In addition, each opto-mechanical subsystem has been validated at cryogenic temperature in a special test cryostat. The 2.5mx1mx1m FRIDA main cryostat is nearly completed. FRIDA is scheduled to complete system testing at the laboratory by the end of 2023.