Silmaril

Silmaril is a new beam combiner designed for high sensitivity. It combines the light from 3 beams in the near-infrared H and K bands. Commissioning of the Silmaril combiner is ongoing.

The Silmaril beam combiner was designed to achieve high sensitivity, and it was installed in the lab in early 2023. Silmaril features a low noise C-RED One detector using electron avalanche photodiode (e-APD) technology from First Light Imaging. The instrument uses bulk optics, rather than single-mode fibers, with a minimum number of optical elements to maximize throughput. The current design is limited to 3 beams to have the capability of measuring closure phases, while not diluting the incoming light with more combinations. An edge filter provides simultaneous data in the H and K-bands with a spectral resolving power of R=35.

An initial commissioning run on UT 2023 July 5-6 succeeded in recording 3-telescope fringes on sky using a C-RED 2 camera. We are waiting for the final delivery of the C-RED 1 detector. Based on performance with the C-RED 2 and simulations, we expect to achieve a limiting magnitude of H=10-11 mag with the final system.