There is a potential need for large (>500 mm diameter) conformal windows for use on air, space, and watercraft.

Freeform surfaces on optical components have become an important design tool for optical designers. Non-rotationally symmetric optical surfaces have made solving complex optical problems easier. The manufacturing and testing of these surfaces has been the technical hurdle in freeform optic’s wide-spread use.

Freeform surfaces are quickly becoming a desired and necessary shape for many refractive and reflective optical systems. In this paper, we will discuss the round-robin study of surface irregularity measurements of a freeform toroidal window.

Freeform applications are expanding and include helmet-mounted displays, conformal optics, and those requiring the extreme precision of EUV. We will discuss the total manufacturing process and highlight the capabilities available today.

This case study will focus on the absolute freeform surface measurement utilizing a custom dual CGH and interferometer set-up, with special emphasis on reference artifacts and surface alignment to measure both the irregularity and the location of the freeform surface simultaneously.

Freeform optical systems are becoming increasingly common due to new design and manufacturing methods. We present an example compact freeform optical system and describe considerations for transfer of the prescription of freeform surfaces for fabrication.

Monolithic multi-surface telescopes combined with freeform optical surfaces provide improvements in optical performance in a smaller footprint as compared to systems with spherical surfaces, while providing superior mechanical stability to traditional telescope assemblies.

This paper will present some of the challenges and solutions of extending freeform polishing capabilities from approximately 150 mm diameter parts to a component of over 500 mm in diameter.

This paper will address challenges that have been encountered in the manufacturing, testing, and handling of freeforms as their size expands up to and beyond 500 mm, and provide future work that will address each challenge.

This paper will discuss challenges faced as a result of scaling up our freeform polishing process from parts with approximately 150 mm diameters, to polishing components with diameters over 600 mm.

Several challenges associated with part size and shape complexity were solved during the manufacture of the largest extreme freeform shape Optimax has fabricated to date.

Freeform optics have emerged as a new tool for optical designers and integrators. Manufacturing innovations are gradually increasing availability of precision freeform optics.

Optical systems must perform under environmental conditions including thermal and mechanical loading. To predict the performance in the field, an integrated analysis combining optical and mechanical software is required to understand optical performance. 

Freeform optical shapes or optical surfaces that are designed with non-symmetric features are gaining popularity. This enabling technology allows for conformal sensor windows and domes that provide enhanced aerodynamic properties.

Conformal windows pose new and unique challenges to manufacturing due to the shape, measurement of, and requested hard polycrystalline materials. Optimax has developed a process for manufacturing conformal windows out of fused silica, glass, zinc-sulfide multispectral, and spinel. 

Freeform optical surfaces are gaining popularity with lens designers and optical system integrators as a method to solve complex optical system design problems. Fortunately, advances in optical manufacturing have opened the possibility for designers to manufacture these complex surfaces.

Freeform optical shapes that are designed with non-symmetric features allow for conformal sensor windows and domes that provide enhanced aerodynamic properties as well as environmental and ballistic protection.

Freeform and conformal optics have the potential to dramatically improve optical systems by enabling systems with fewer optical components, reduced aberrations, and improved aerodynamic performance.

For more than 100 years, optical imaging systems were limited to rotationally symmetric lens elements, due to limitations in processing optics. However, the present application of CNC machines has made the fabrication of non-rotationally symmetric lenses, such as freeform surfaces, economical.

Freeform optical shapes or optical surfaces that are designed with non-symmetric features are gaining popularity with lens designers and optical system integrators. Tolerances on a freeform optical design influence the optical fabrication process.

Freeform surfaces typically have little to no symmetry, making the alignment of the surfaces difficult. Fiducials are required to achieve higher accuracy measurements of freeform optical surfaces.

Freeform optical surfaces, which have little to no symmetry, are gaining popularity with lens designers and optical system integrators. Using fiducials properly leads to higher accuracy measurements and allows more control of the surface throughout the manufacturing process.

Our robotic polishing platforms are able to polish large, difficult-to-make optical surfaces with minimal surface error. 

Proper metrology is required to monitor and verify the freeform fabrication processes to improve capability and precision.

The freeform monolithic multi-surface telescope design has all its off-axis optical surfaces manufactured from a single optical blank, resulting in truly monolithic telescope design, providing improvements in stability and payload.