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.
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.
Ultra-thin waveplate for optical communications
It has insertion loss comparable to that of a quartz plate and can have multiple axial orientations on a single element.Compact and free polarization control can be realized in optical transceivers, optical modulators, receivers, and wavelength selective switches (WSS) in digital coherent systems.
PI cameras are capable to obtain polarization information real-time, as a normal image, and at high-resolution.They are used in many areas including recognition of dark objects using their polarization signature, real-time polarization monitoring of laser beams, etc.
Full-length, full-width film quality control
With the industry's first full-surface measurement technology for birefringence distribution in optical films, we contribute to the improvement of film quality that leads to the assurance of image quality across the entire display screen.
Birefringence & Stress Strain Measurement
We have improved conventional birefringence measurement from point measurement to 2-D surface measurement. High-speed, high-precision birefringence measurement contributes to quality evaluation and functional improvement of optical materials.
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.