Elements that handle polarized light include polarizers and wave plates.
This time, we will introduce a novel and versatile polarization control technology that used photonic crystals！

Photonic crystal optical devices

Image of a photonic crystal and an electron microscope image of its cross-sectional structure.

Polarized light extinction ration and birefringence retardation can be controlled by the number of film layers.
https://www.photonic-lattice.com/photoniccrystal/

Feature１

Local polarization can be freely controlled by changing the anisotropy axis for each location.
We are capable of manufacturing ultra-integrated polarizers and waveplates, which are used as filters in polarization imaging cameras and as axially symmetric polarized beam forming elements.

Waveplate with arbitrarily arranged anisotropy axis：The groove lines on the surface correspond to the anisotropy axis.

Feature２

The substrate and film are all manufactured from inorganic materials such as hafnium oxide, so they have light and heat resistance and can be used without problems as elements for high-power lasers.
Another major feature is that it can accommodate a wide range of wavelengths, from 250nm to 12μm.

Our photonic crystal elements support ultra-high range(from deep ultraviolet to mid-infrared).

　　　　　　　　　　　　　　Available area

※Mid-infrared region compatible elements are under development.

Feature３

It does more than just change the polarization direction of light.
By segmenting the wave plate, it is possible to realize beam shapes that are not possible with ordinary polarizing elements. Compared to conventional beam shapers (such as Does: diffractive optical elements), it is easier to achieve high diffraction efficiency, and the surface can be easily cleaned and bounded to other elements, making it deal for laser processing applications.

Conventional beam shapers can be broadly divided into two types.
The first is a ROE (refractive optical element), and the second is a DOE focuses and diffuses light (direction and intensity) by diffracting light on the microstructure on the element surface. At our company, we perform control by creating a phase shift when light passes through a photonic crystal. Theoretically, the direction efficiency is 100%. Beam polarization control and shape control can be performed simultaneously.
It is possible to design light shapes that cannot be achieved with standard ROE.
Additionally, the shape of the element itself is thinner and more uniform compared to ROE.

Polarized beam shaper using photonic crystals

Beam shape changed from Gaussian to box by polarizing beam shaper using photonic crystals

Feature４

Reliable and complete zero-order waveplates (true zero-order waveplates) can be made. A zero-order wave plate (true zero-order waveplates) is a waveplate that can obtain the desired retardation at the zero-order at the designed wavelength.

For example, a zero-order half-waveplate for a wavelength of 266nm made from a birefringent material like quartz would have a thickness of around 11μm. However, since the photonic crystal is deposited on a quartz substrate (a material that normally does not exhibit birefringence), it is easy to handle.

The advantage of using a zero-order waveplate is that the stability of the retardation obtained against changes in wavelength and temperature, as well as oblique incidence, is extremely high.

True zero-order waveplate fabricated with photonic crystals

Please contact us

・”I want to create a beam with different polarization states depending on the location….”
・”I’m looking for a polarizing element that can be used as short wavelengths, but it’s difficult to use liquid crystal or organic multilayer films….”
・”I want to use a beam shaping element by bonding it with other optics….”

If you have such problems or requirements, why not try using our photonic crystal elements?

We respond promptly to inquiries about polarization-related technologies and beam shaping technologies, as well as requests for element prototyping.

Please also refer to this technical introduction.
https://www.photonic-lattice.com/technology/