Surmet continuously strives to develop novel, advanced optical ceramics products for current and future defense and
commercial systems. Using conventional powder processing techniques, Surmet has made substantial progress in its ability
to manufacture large ALON® sensor windows, lenses, domes and transparent armor. In addition to transparency, Surmet
has demonstrated the ability to incorporate other capabilities into its optical ceramic components, including: EMI shielding,
heating, internal antennas and cooling channels.
Working closely with the University of Rochester, Surmet has developed gradient index (GRIN) optics in ALON for
use in the visible through the MWIR applications. Surmet has demonstrated the ability to tailor the refractive index of
ALON® Optical Ceramic by either varying its composition or through the addition of dopants. Smooth axial and radial
gradient profiles with ~0.055 change in refractive index, over depths of 1-8 mm (axial) and over 20 mm radius (radial)
have been demonstrated. Initial design studies have shown that such elements provide unique capabilities. Radial gradients
in particular, with their optical power contribution, provide additional degrees of freedom for color correction in broadband
Surmet continues to mature ALON® GRIN technology along with the associated metrology. Surmet is committed to
the development of its ALON® GRIN capability as well as finding insertion opportunities in novel imaging solutions for
military and other commercial systems.
Aluminum Oxynitride (ALON® Optical Ceramic) combines broadband transparency with excellent mechanical properties. ALON’s cubic structure means that it is transparent in its polycrystalline form, allowing it to be manufactured by conventional powder processing techniques. Surmet controls every aspect of the manufacturing process, beginning with synthesis of ALON® powder, continuing through forming/heat treatment of blanks, ending with optical fabrication of ALON® windows. Surmet has made significant progress in its production capability in recent years. Additional scale up of Surmet’s manufacturing capability, for complex geometries, larger sizes and higher quantities, is underway. The requirements for modern aircraft are driving the need for conformal windows for future sensor systems. However, limitations on optical systems and the ability to produce windows in complex geometries currently limit the geometry of existing windows and window assemblies to faceted assemblies of flat windows. Surmet’s ability to produce large curved ALON® blanks is an important step in the development of conformal windows for future aircraft applications.
The requirements for modern aircraft are driving the need for conformal windows for future sensor systems. However, limitations on optical systems and the physical properties of optically transparent materials currently limit the geometry of existing windows and window assemblies to faceted assemblies of flat windows held in weight bearing frames. Novel material systems will have to be developed which combine different materials (e.g. ductile metals with transparent ceramics) into structures that combine transparency with structural integrity. Surmet’s demonstrated ability to produce novel transparent ceramic/metal structures will allow us to produce such structures in the types of conformal shapes required for future aircraft applications. Furthermore, the ability to incorporate transparencies into such structures also holds out the promise of creating multi-functional windows which provide a broad range of capabilities that might include RF antennas and de-icing in addition to transparency. Recent results in this area will be presented.