Lateral shearing interferometry method based on double-checkerboard grating by suppressing aliasing effect

Area of Science:

• Optics and Photonics
• Wavefront Sensing
• Interferometry

Background:

• Ronchi lateral shearing interferometry offers a simple, reference-free method for high-precision wavefront aberration measurement.
• Conventional methods use sequential orthogonal gratings, introducing mechanical errors during conversion and limiting accuracy.
• Two-dimensional wavefront reconstruction requires complex setups and precise alignment.

Purpose of the Study:

• To introduce a novel double-checkerboard grating for lateral shearing interferometry.
• To streamline the wavefront measurement process by eliminating grating conversion steps.
• To improve the accuracy and robustness of two-dimensional wavefront reconstruction.

Main Methods:

• Utilizing a double-checkerboard grating to acquire two-dimensional shear information with a single phase shift.
• Applying scalar diffraction theory to model the optical path and analyze the double-checkerboard shearing interferometry.
• Developing a new reconstruction algorithm to extract two-dimensional shear phase and suppress diffraction order aliasing.
• Employing iterative optimization to reduce fitting errors for high-precision wavefront reconstruction.

Main Results:

• The proposed method successfully obtains shear information in two directions without mechanical grating conversion.
• A new reconstruction algorithm effectively extracts two-dimensional shear phase, mitigating aliasing effects.
• Iterative optimization significantly reduces fitting errors, leading to high-precision wavefront reconstruction.
• The double-checkerboard method demonstrates improved robustness and stability in noisy environments compared to conventional techniques.

Conclusions:

• The double-checkerboard grating lateral shearing interferometry provides a more streamlined and accurate approach to wavefront sensing.
• This method overcomes the limitations of conventional Ronchi interferometry by eliminating mechanical errors.
• The developed technique offers enhanced stability and robustness, making it suitable for challenging measurement conditions.