Optical wavefront measuring device and measuring method thereof
AssigneeNational Central University
InventorChao-Wen Liang
Life of this patent
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Abstract
A device and method for measuring the decentration of optics under test is provided. The device comprises a rotational spindle for loading and rotating the optics under test, a light source module for providing incident light beam to the optics under test, and a wavefront sensor for receiving testing light beams with different exposures from the optics under test at a plurality of azimuthal directions.
Claims17
An optical wavefront measuring device for testing an optics under test, the optical wavefront measuring device comprising:
- a rotational spindle rotating the optics under test in a plurality of different azimuthal directions;
- a light source module emitting an incident light beam that propagates to the optics under test, from which testing light beam containing the measured wavefront of the optics under test is generated;
- a wavefront sensor acquiring the testing light beam passing through the optics under test rotated in at least two of the plurality of different azimuthal directions;
- and
- a computing device processing data associated with the testing light beam;
- wherein the wavefront sensor captures a plurality of camera frames with different exposures for each of the plurality of different azimuthal directions to acquire the testing light beam;
- and
- the camera frames with different exposures for each of the plurality of different azimuthal directions are synthesized into a measured wavefront corresponding to the respective azimuthal direction, the computing device is configured to receive the measured wavefronts obtained at the at least two azimuthal directions, determine, from the measured wavefronts, a fixed alignment error aberration (WDC) attributable to misalignment of the optical wavefront measuring device, and subtract the fixed alignment error aberration (WDC) from the measured wavefronts to obtain an angle-dependent aberration attributable to the optics under test.
An optical wavefront measuring method suitable for an optical wavefront measuring device to test optics under test, the optical wavefront measuring device comprising a rotational spindle rotating the optics under test, a light source module, a wavefront sensor, and a computing device, the optical wavefront measuring method comprising:
- moving the light source module to a first pre-determined position, and moving the wavefront sensor to a second pre-determined position;
- providing an incident light beam incident on the optics under test by the light source module, and a testing light beam containing measured wavefront of the optics under test propagates out of the optics under test;
- when the optics under test is rotated to a plurality of different azimuthal directions by the rotational spindle, the testing light beam passing through the optics under test rotated in at least two of the plurality of different azimuthal directions is acquired by the wavefront sensor;
- and
- capturing a plurality of camera frames with different exposures for each of the plurality of different azimuthal directions to acquire the testing light beam by the wavefront sensor;
- wherein synthesizing the camera frames with different exposures for each of the plurality of different azimuthal directions into a measured wavefront corresponding to the respective azimuthal direction;
- and
- receiving the measured wavefront corresponding to the respective azimuthal direction, by the computing device;
- determining a fixed alignment error aberration (WDC) attributable to misalignment of the optical wavefront measuring device from the measured wavefront, by the computing device;
- and
- subtracting the fixed alignment error aberration (WDC) from the measured wavefront to obtain an angle-dependent aberration component attributable to the optics under test, by the computing device.
Dependencies are inferred from the claim text.