Optimized design of a gravitational wave telescope system based on pupil aberration

The telescope is vital for accurate gravitational wave detection in the TianQin project. It must meet criteria like a geometric tilt-to-length (TTL) coupling noise c o e f f i c i e n t≤0.02√2n m/µr a d and wavefront R M S≤λ/30. Analyzing the pupil aberration's impact on geometric TTL noise, we devised an optimization method using the chief ray spot diagram's standard deviation. Implementing this in Zemax with a ZPL macro, we designed an optical system meeting TianQin's requirements. The system has a maximum geometric TTL noise coefficient of 0.0250 nm/µrad over the science FOV and a wavefront RMS of 0.0111λ, confirming the method's feasibility.