Super-compact shearography based on a single diffractive optical element with 3-in-1 phase mask.

Area of Science:

• Optics and Photonics
• Optical Metrology

Background:

• Quantitative shearography traditionally uses multiple optical elements for imaging, shearing, and phase shifting.
• Conventional designs can be bulky, complex, and less stable.

Purpose of the Study:

• To introduce a new, compact, and robust design framework for quantitative shearography.
• To integrate the core functions of shearography into a single diffractive optical element (DOE).

Main Methods:

• Development of a "3-in-1 phase mask" by integrating imaging, shearing, and phase shifting functions into a single DOE.
• Utilizing a slicing, splicing, and alternating strategy with Fresnel lenses and an echelle grating to create the DOE.
• Achieving coaxial optics through the use of a single operating component.

Main Results:

• Demonstration of a super-compact, robust, and stable shearography system.
• The system's design allows for easy adjustment of shear amount, direction, and working distance by modifying the DOE.
• Potential for field applications outside of traditional optics laboratories.

Conclusions:

• The proposed 3-in-1 phase mask offers a breakthrough in shearography design, moving from discrete components to phase manipulation.
• This integrated DOE approach significantly enhances system compactness and stability.
• The design shows promise for future development using lithography, micromachining, and metasurfaces for advanced optical metrology.