ABSTRACT
With the advent of 3D printing optical elements, new techniques for manufacturing gradient-index (GRIN) optics have been realized that blend multiple materials in the deposition process. A method to achieve spectral splitting using multi-material GRIN optics is presented. The GRIN is additionally used to generate optical power, allowing for planar entrance and exit surfaces. It is shown that this simultaneous focusing and spectral splitting is not feasible with a two-material GRIN. A comparative design study is then conducted using three and four-material GRIN. A four-material design with optimized materials is also presented to showcase the potential for this new design form.
ABSTRACT
Recent advancements in additive manufacturing have enabled new methods of fabricating gradient-index (GRIN) optics by blending multiple materials in the deposition process. A design study highlighting the advantages of multi-material GRIN optics is presented. It is shown that additional materials in the GRIN allow for higher orders of color correction. A new multi-material refractive index representation, which constrains the GRIN to real materials, is also presented.
ABSTRACT
The annular folded lens (AFL) is a design form offering large aperture, high-resolution imaging in a very axially compact package. The folded optic can be made monolithic for easier fabrication and alignment, yet the introduction of refractive surfaces with a dispersive optical material gives way to chromatic aberrations. AFL designs using homogeneous media are generally limited to the monochromatic regime, with polychromatic performance greatly reduced. By introducing freeform gradient-index (F-GRIN) media, monolithic AFL designs can achieve higher monochromatic performance as well as provide color correction for diffraction-limited polychromatic imaging. Monochromatic and polychromatic design methodologies are surveyed where the F-GRIN is constrained to remain feasible for fabrication.
