Hybrid meta/refractive lens design with an inverse design using physical optics

Area of Science:

• Optical Engineering
• Nanotechnology
• Computational Optics

Background:

• Hybrid lenses integrate refractive and metasurface optics for enhanced performance.
• Metasurfaces offer advanced aberration correction capabilities.
• Optimizing metasurface placement within optical systems is challenging.

Purpose of the Study:

• To develop an algorithm for optimizing metasurface nanostructures in hybrid lenses.
• To enable flexible integration of metasurface and refractive elements.
• To improve the focusing efficiency of optical systems.

Main Methods:

• Developed a scalar field, ray-wave hybrid propagation method for efficient metasurface optimization.
• Implemented an adjoint gradient optimization framework.
• Demonstrated the algorithm with numerical examples of various lens configurations.

Main Results:

• The algorithm allows metasurfaces to be placed in object and image spaces.
• A midwave infrared lens design achieved over 90% average focusing efficiency with optimized metasurfaces.
• Compared to image-space-only metasurfaces (73% efficiency), the new approach shows superior performance.

Conclusions:

• The presented algorithm offers a versatile and effective method for designing advanced hybrid lenses.
• Optimizing metasurface placement, including in object space, significantly boosts optical system performance.
• This approach advances the capabilities of metasurface integration in optical design.