About Photonic Crystals
Photonic crystals are artificial structures made in regular patterns, a technology that enables control of light that cannot be achieved with naturally occurring materials. However, because of the need to precisely fabricate very fine structures, few companies have even put this technology to practical use.
We have the technology to create photonic crystals simply by stacking multiple layers of films on a wafer with uneven surfaces.
The size of the unevenness can be freely varied from tens of nm to several micrometers.
We can create precise three-dimensional structures with a simple process of a single patterning and deposition of the films.
For example, in the structure shown on the right figure, anisotropy in the structure causes a difference in optical properties between vertical and horizontal polarization. The direction of anisotropy is determined by the pattern of the wafer.
When the thickness of each layer is controlled, the interference of light in the multilayer film allows it to function as a polarizer, in which one polarization is reflected, or as a waveplate, in which the polarization state is changed.
By changing the pattern of the wafer, polarizers and waveplates with various axial distributions can be freely made. In other words, free polarization distribution can be realized.
This technology is used in polarization imaging sensors, multichannel polarization conversion elements for optical communications, and as special filters for semiconductor wafer inspection.
More recently, we have introduced the concept of geometric phase and are working to realize new functions through phase control. We have realized diffraction gratings that can separate left and right circular polarization and control beam shape.
The control of not only polarization but also phase is developing new applications.
Custom Polarizer & Phase Plates
Our products can be customized not only for the optical properties, but also for the shape and the spatial distribution of those properties. In particular, they can be made non-uniformly, having a segmented structure or a curved axis along the surface. Customization of the patterned polarizer/waveplate is welcome.
Half-Mirror Polarizer for Laser Cavity
Reflectivity for each polarization can be tuned separately. As a half-mirror in a laser resonance cavity, the element is used to generate and select the output polarization of the laser. Because of its inorganic nature, the element can withstand very high optical power.
True Zero Order Waveplate/Ultra-Violet Polarizers
Photonic crystal waveplates are reliable and perfect zero-order waveplates with small incident angle dependence.For example, a zero-order half-wave plate made of quartz for a wavelength of 266 nm in the ultraviolet region would be about 11 μm thick, but a photonic crystal is deposited on a quartz plate, making it easy to handle.
Next-generation Optical Communications
Polarization control is becoming increasingly important in next-generation optical communications. In addition to application examples of our proprietary photonic crystals, we also introduce upcoming functions in the future.
Ultra-precision micro laser processing
Microfabrication technology is becoming increasingly important for next-generation EVs and semiconductor devices. We support the development of this field with our unique beam shaping, polarization control, and high speed temperature imaging technologies.