Detection system for long-range optical surface profile

Abstract

The invention provides a detection system for a long-range optical surface profile. The detection system comprises a mobile optical head and an f-theta angle detection system. The mobile optical head consists of a tail fiber, a beam splitter, and a concave mirror, wherein the beam splitter and the concave mirror form an equivalent pentaprism. The mobile optical head is configured to emit an input light beam through the tail fiber, so that the light beam passes through the beam splitter and then enters a surface of a to-be-detected optical device; the light beam is reflected to the beam splitter by the surface of the to-be-detected optical device; the part of reflected light beam is reflected to the concave mirror by the beam splitter; and then the light beam is reflected to the f-theta angle detection system by the concave mirror along a direction perpendicular to a normal of a corresponding measuring point of the surface of the to-be-detected optical device, so that a measuring light spot is formed in the f-theta angle detection system. According to the invention, the number of reflection and transmitting optical devices causing errors can be reduced; a system error caused by horizontal movement of a measuring light beam during measurement of different angles can be reduced; and the measuring precision is improved.

Description

technical field [0001] The invention relates to the field of high-precision mirror surface shape detection, in particular to a long-distance optical surface shape detection system. Background technique [0002] Due to the strong penetrability of X-rays, they are used in many application fields. For example, synchrotron radiation sources, free electron lasers, and large astronomical telescopes all use large-scale mirrors with a length of about 1 meter to face X-rays. In order to ensure the optical quality of X-rays (such as directionality and coherence), or to focus X-rays to nanometer-scale spots, these large-scale mirrors are usually required to have nanometer-level high precision and nanometer Inclination accuracy in radians. [0003] For such a high-precision large-size mirror, its processing and inspection are worldwide problems, and inspection is a prerequisite for processing a high-precision mirror. Long-travel profiler (LongTraceProfile, LTP) based on thin beam scan...

AI Technical Summary

Problems solved by technology

from figure 1 It can be seen that the measuring beam starts to deviate from the measuring point on the mirror to be tested 6', so the measuring point on the mirror to be tested 6' is the reference point for calculating the lateral displacement of each optical element in the pp-LTP, so for the same The deflection angle of the optical device in the system is farther away from the geometric optical path of the measuring point on the mirror surface 6' to be measured, the greater the lateral shift of the measuring beam on the optical device is, and it is this lateral shift that makes each optical device in the system introduce different points of error

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