A high-precision measurement method for characteristic parameters of an equal-thickness off-axis parabolic mirror

Abstract

The invention discloses a high-precision measurement method for characteristic parameters of an equal-thickness off-axis parabolic mirror. A detection system adopted by the method comprises a laser interferometer, the off-axis parabolic mirror, a standard plane mirror, a reference cross reticle, a small-plane reference mirror, a theodolite and a guide rail with a grating ruler. The optical non-contact high-precision measurement method can realize high-precision measurement of key characteristic parameters of the off-axis amount, the off-axis angle, the equal-thickness angle and the focal length of the equal-thickness off-axis parabolic mirror at the same time, and lays a foundation for high-precision processing and adjustment of an off-axis reflection exposure system.

Description

technical field [0001] The invention relates to the field of optical detection, in particular to a high-precision measurement method for characteristic parameters of an equal-thickness off-axis parabolic mirror. Background technique [0002] Large-aperture diffraction gratings have important applications in inertial confinement fusion, especially pulse compression gratings in high-power chirped pulse amplification systems. However, the fabrication of large-aperture, high-quality diffractive wavefront gratings by holographic exposure is limited by the aperture of the exposure lens. In recent years, with the application of off-axis parabolic mirrors more and more widely, and the manufacturing technology has become more and more mature, it has become a feasible new method to make diffraction gratings by using large-diameter off-axis parabolic mirrors to form a static interference field exposure light path. Such as figure 1 shown. However, due to the small field of view of th...

AI Technical Summary

Problems solved by technology

The general detection method cannot accurately give the angle. For example, the conventional measurement method is to directly use a tape measure to approximately measure the distance from the focal point to the center of the off-axis parabolic mirror in the autocollimation optical path, and approximate the off-axis amount. Geometric relationship to calculate focal length and off-axis angle

Since a tape measure is used for measurement, and the geometric position relationship of the parabola cannot be accurately positioned, the measurement accuracy is poor, and the error is at the millimeter level. At the same time, this method cannot obtain equal thickness angles, and this type of contact measurement is also easy to scratch the surface; some theodolites are also used And the measurement system of the grating ruler guide rail, but this method uses multiple theodolites (not less than four), the structure is complex, the cost is high, and the equal thickness angle cannot be given.

Therefore, none of the existing measurement methods can precisely calibrate the isoptic angle, off-axis amount, off-axis angle, and focal length at the same time

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