Diffractive Optical Elements

NIL Technology are specialized in diffractive optical elements (DOEs). We make diffractive optics that are customized to your specific needs. This enables you to efficiently shape light and to consequently improve the overall performance and flexibility of your products.

Diffractive Optical Element
Diffractive Optical Element

4 levels, fused silica, 500 nm pixels, 500 nm step height

Cross-section of replication in polymer (device) with steep side walls, sharp corners and low roughness

Why choose NIL Technology to make your DOEs?

NIL Technology offers you diffractive optical elements that are customized to your specific needs. We have made diffractive optics for many years and have extensive experience in complex and high precision DOEs.

With design, manufacturing and optical characterization all within NILT we can offer rapid turnaround times for our customers.

Through high accuracy in the manufacturing we are able to reach high performance optics. Some of the benefits of our DOEs include:

  • High definition/pattern fidelity
  • High aspect ratios
  • Steep side walls
  • Multi-levels
  • High resolution
  • Low roughness
Precise We have high-quality production methods and years of experience with high-precision diffraction structures
Adaptable Easily replace or combine refractive optics with diffractive optics
Energy-efficient Shape and divide laser beams to control intensity
Custom-made Customized to your specific needs and specifications
Effective Be able to precisely control the phase across the aperture and make complex intensity

With NILT, you can expect improved diffraction efficiency and better stray light suppression, among other key benefits. Contact us to get an overall understand of how it will affect your optical applications and product performance by working with NIL Technology.

We can be your partner throughout the whole product journey, from idea to design and production. See our services here and contact us to get more information.

Our diffractive optics

Diffractive Optical Elements and applications

Diffractive optical elements have the advantage of enhancing the value of laser systems. They have many functions and are useful for many types of applications. For example, you can find diffractive optics in long range distance sensors like LiDAR / LADAR (Light Detection And Ranging), short range distance sensors, position sensors, motion detection and projection systems.

Beam shaping, beam splitting, diffusers, pattern projections, diffractive focusing lenses and gratings are just some of the diffractive optics that we are working with. However, it is not just laser systems that benefit from DOEs. Systems based on other light sources can also benefit from diffractive optics even though it is broadband light sources.

You can read more about optical applications here

Diffractive Optical Elements and laser light

Green laser light through a diffractive optical element (injection molded in plastic) creating a NILT logo

Masters for Diffractive Optics

We make masters for diffractive optics in silicon and fused silica. We have no fundamental limits to how deep and how many levels we can make, 16 levels have been demonstrated.

Masters for diffractive optics are used directly in the replication process or to generate sub-masters. In some cases, generations of sub-masters for volume manufacturing by wafer level replication.

From a DOE master, we can also make Ni molds for use e.g. in an injection molding-based volume manufacturing setup.

Specifications of our masters for Diffractive Optics

Specifications
Master Material
Silicon, fused silica, Nickel
Height/deptyh levels
No fundamental limit (16 discrete levels demonstrated)
Minimum dimensions (w)
Down to 50 nm – depending on material, number of levels and aspect ratio
Max aspect ratio (width:height)
1:3 to 1:10 (depending on material)
Max substrate diameter
2″, 4″, 6″, 8″
Vertical accuracy between levels
Better than 6%
Overlay accuracy (centre-to-centre) between diff layers
Better than 30 nm
Lateral tolerance (same layer) (w)
Better than 15 nm

Diffractive Optical Elements (DOEs) are optical components made of structures with dimensions comparable to the wavelength in complex arrangements. Based on the types of application, DOEs are capable of manipulating an incident light’s phase and amplitude with the purpose of creating a desired output pattern with a unique functionality.

Diffractive optics with a given function follows the same principles as a diffractive grating with a repetitive pattern of two or more levels, formed on the surface of a substrate – typically etched into the surface of a hard substrate or replicated in a polymer on the surface of a substrate or made purely in polymer. The depth of the pattern is in the order of the wavelength of the light, specific to the application, adjusted to the refractive index of the material of the DOE.

Nowadays, with the aid of high accuracy advanced micro and nano-lithography fabrication techniques, diffractive optics can be engineered with feature sizes ranging from few hundreds of nanometers.

Introducing DOEs into classical optical systems can make then smaller and lighter since the diffractive optics are much thinner and lighter optical components compared to their bulky refractive counterparts.

Replacing refractive optical systems with systems based on DOEs, can both add functionality while maintaining a high efficiency, drive down the cost and shrink the module size which are all crucial factors for integrated optics.

You can read more about DOEs right here

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