Measuring device having ideal wavefront generator for detecting point diffraction interferometric wavefront aberration of measured optical system and method for detecting wavefront aberration thereof

Patent metadata

Field	Value
Publication number	US-9863841-B2
Application number	US-201514986560-A
Country	US
Kind code	B2
Filing date	Dec 31, 2015
Priority date	Dec 24, 2015
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A point diffraction interferometric wavefront aberration measuring device comprising an optical source, an optical splitter, a first light intensity and polarization regulator, a phase shifter, a second light intensity and polarization regulator, an ideal wavefront generator, an object precision adjusting stage, a measured optical system, an image wavefront detection unit, an image precision adjusting stage, and a data processing unit. The center distance between the first output port and the second output port of the ideal wavefront generator is smaller than the diameter of the isoplanatic region of the measured optical system and is greater than the ratio of the diameter of the image point dispersion speckle of the measured optical system over the amplification factor thereof. A method for detecting wavefront aberration of the optical system is also provided by using the device.

First claim

We claim:

1. A device for measuring point diffraction interferometric wavefront aberration, comprising:
an optical source,
an optical splitter,
a first light intensity and polarization regulator,
a phase shifter,
a second light intensity and polarization regulator,
an ideal wavefront generator having a first input port, a second input port, a first output port, and a second output port,
an object precision adjusting stage,
a measured optical system having an object plane and an image plane, the image plane being on an image side,
an image wavefront detection unit having an image mask and a photoelectric sensor, the photoelectric sensor comprising a two-dimensional detector,
an image precision adjusting stage, and
a data processing unit,
wherein the optical splitter is placed along an advancing direction of an optical path of an output light from the optical source;
the optical splitter splits the output light into a light path adjustable light path and a light-path-fixed light path;
the first light intensity and polarization regulator and the phase shifter are arranged along the light path adjustable light path, followed by the first input port of the ideal wavefront generator, and the first light intensity and polarization regulator is placed either prior to or subsequent to the phase shifter;
the second light intensity and polarization regulator is arranged along the light-path-fixed light path, followed by the second input port of the ideal wavefront generator;
the first output port and the second output port of the ideal wavefront generator are on the object plane of the measured optical system;
the ideal wavefront generator is supported and precision positioned by the object precision adjusting stage;
the image wavefront detection unit is situated on the image side of the measured optical system, the image mask of the image wavefront detection unit is situated on the image plane of the measured optical system, and the two-dimensional detector of the photoelectric sensor is situated subsequent to the image mask along the advancing direction of the light;
the image wavefront detection unit is supported and precision positioned by the image precision adjusting stage;
output signal of the image wavefront detection unit is inputted to the data processing unit;
wherein the ideal wavefront generator is an optical component transforming a light of a first input port and a second input port thereof to a standard spherical wave in a scope of an object numerical aperture of the measured optical system, and the standard spherical wave is subsequently outputted respectively from a first output port and a second output port thereof; and
a center distance s o between the first output port and the second output port of the ideal wavefront generator is smaller than a diameter of an isoplanatic region of the measured optical system and is greater than a ratio of a diameter of an image point dispersion speckle of the measured optical system over an amplification factor thereof.

2. The device for measuring point diffraction interferometric wavefront aberration according to claim 1 , wherein the first light intensity and polarization regulator comprises an adjustable attenuator and a polarization controller, and the adjustable attenuator is connected prior to or subsequent to the polarization controller along the advancing direction of light.

3. The device for measuring point diffraction interferometric wavefront aberration according to claim 1 , wherein the first light intensity and polarization regulator comprises a polarization analyzer and a rotary stage; the rotary stage rotates the polarization analyzer to change the direction of the transmission axis of the polarization analyzer, thereby changing the polarization and light intensity of the output light.

4. The device for measuring point diffraction interferometric wavefront aberration according to claim 1 , wherein the first light intensity and polarization regulator comprises a polarization controller and a polarization analyzer; the polarization controller and the polarization analyzer are successively connected along the advancing direction of light; by adjusting the polarization of light via the polarization controller, the light intensity of the polarization analyzer is changed.

5. The device for measuring point diffraction interferometric wavefront aberration according to claim 1 , wherein the first light intensity and polarization regulator comprises an adjustable attenuator, and only adjusts light power along the light path.

6. The device for measuring point diffraction interferometric wavefront aberration according to claim 1 , wherein the phase shifter comprises a columnar piezoelectric ceramic and a single-mode fiber loop winding thereon; by changing the driving voltage of the columnar piezoelectric ceramic, the diameter of the columnar piezoelectric ceramic changes, thus the length of the single-mode fiber loop and thereby the light path is changed.

7. The device for measuring point diffraction interferometric wavefront aberration according to claim 1 , wherein the phase shifter comprises a beam splitter prism, a reflector, and a piezoelectric ceramic; along the direction of the incident light is arranged the beam splitter prism, and the reflector is arranged in the direction of the reflection light of the beam splitter prism; light reflected by the reflector comes out via the beam splitter prism; as the reflector is mounted on the piezoelectric ceramic, by changing the driving voltage of the piezoelectric ceramic, the length of the piezoelectric ceramic is changed to move the reflector, thus changing the light path.

8. The device for measuring point diffraction interferometric wavefront aberration according to claim 1 , wherein the image wavefront detection unit comprises an image mask, a photoelectric sensor, and a support, and the image mask is situated on an image plane of the measured optical system; along an advancing direction of light and subsequent to the image mask is arranged the photoelectric sensor, and the support is a mechanical component supporting the image mask and the photoelectric sensor.

9. The device for measuring point diffraction interferometric wavefront aberration according to claim 8 , wherein the photoelectric sensor comprises a transform optical mirror set and two-dimensional detector; the image mask is situated on a front focus plane of the transform optical mirror set, the two-dimensional detector is situated on a rear focus plane of the transform optical mirror set, and the transform optical mirror set is an imaging-capable single lens, while the two-dimensional detector is a CCD.

10. The device for measuring point diffraction interferometric wavefront aberration according to claim 9 , wherein the support consists of a fixed component, and the precision adjusting component is absent.

11. The device for measuring point diffraction interferometric wavefront aberration according to claim 8 , wherein the support comprises a fixed component and a precision adjusting component; the precision adjusting component is supported on the fixed component, the image mask is supported on the precision adjusting component, and the photoelectric sensor is supported on the fixed component.

12. The device for measuring point diffraction interferometric wavefront aberration according to claim 8 , wherein the photoelectric sensor comprises a single two-dimensional detector; the two-dimensional detector is disposed subsequent to the image mask along the advancing direction of light, and is parallel to the image mask.

13. The device for measuring point diffraction interferometric wa

Assignees

• Shanghai Inst Optics & Fine Mech Cas

Inventors

• Wang Xiangzhao
• Tang Feng
• Zhang Guoxian
• Xu Shifu

Classifications

• G01M11/0271 Primary

  by using interferometric methods · CPC title

• G01J9/0215 Primary

  by shearing interferometric methods · CPC title

• G03F7/706

  Aberration measurement · CPC title

• G01J2009/0265

  with phase modulation · CPC title

• G01J2009/0223

  Common path interferometry; Point diffraction interferometry · CPC title