Research on Adjustment Method of the Active Segment in a Two-mirror Active Optics System

A two-mirror active optics system is established to simulate the relative pose relationship between the both segments. A pose detection method is proposed to detect the three Degrees of Freedom (DOFs), tip/tilt and piston, of the active segment. It is a combinational method of two edge sensors and a laser-CCD based tilt sensor. The theoretical control matrix and the measured control matrix are used to carry out active calibration experiments. The experiment shows that the maximum Root Mean Square (RMS) error of the edge sensors is about 7.4 nm and the tilt about 0.080″ when the theoretical control matrix is used. While the measured control matrix is used, the edge sensor's RMS error is about 7.3 nm, and the tilt about 0.076″. The research offers a potential solution to the problem of insufficient detection of the DOFs between the mirrors segmented in a ring.