Design and testing of an on-sky astrophotonic telescope platform for on-chip instrumentation

Bulk optical astronomical instruments face significant cost, complexity, flexure and alignment challenges with increasing next generation telescope sizes. Astrophotonics can mitigate these issues by using compact optical fiber or chip-based instruments. Here we present the design and development of a single-mode fiber coupled optical telescope system (ARTEMIS) designed for the demonstration of novel integrated astrophotonic instrumentation. Using a 4 cm fiber collimator as a telescope, we show on-sky measurements from an integrated astrophotonic chip. We have demonstrated the ability to detect <0.002% absorption depth changes of telluric CO2 lines using a sub-centimeter scale astrophotonic correlation spectroscopy chip with the sun as a background light source. These results provide a route towards demonstrating astrophotonic instrumentation on the larger 35 cm ARTEMIS telescope for the atmospheric characterization of smaller, fainter targets such as planets.