The future of augmented reality

  • A Bragg polarization grating (BPG) is an optically “thick” grating that follows (2-4um)
  • Bragg PGs are analogous to Volume Phase Holograms and Volume Bragg Gratings
Image of BPG equation

How It Works

BPGBPGs are a special case of polarization gratings that operate in the Bragg regime or Q>1. It has several unique properties that make it ideal for several applications including augmented and virtual reality. When operating in the Bragg regime, a polarization grating will diffract only a single polarization (+1st order) and leave the orthogonal polarization un-diffracted. With a circularly polarized input, the efficiency can reach up to 99%. For very wide field of views, the efficiency can be as high as 90%.

bragg polarization

Technology Comparison

Traditional Grating ImagineOptix BPG
Field of View 20 Degree 60 Degree
Grating Efficiency 40% 99%
Thickness > 100um 2um

FAQs about BPGs

Q. What is the smallest grating period you can make?
A. We are currently able to fabricate down to 300nm. We are working to reduce this further.

Q. Will your technology work with other waveguide technologies, such as surface relief?
A. Yes. We have successfully combined our in-coupling BPGs and a surface relief out-coupling grating.

Q. What is the field of view (FOV) that is possible with BPGs?
A. We can achieve up to ±40° in the direction of diffraction. The diagonal FOV is significantly larger.

White Papers about BPGs

Click here for Technical Details including Specification and Benefits of our BPGs.


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Some Questions to Consider

These are typical questions we like to ask when engaging you as a customer to help best assess and understand your needs and challenges.

  • What are the key issues with your current solution?
  • Describe the major optical challenges you are facing. Is it low efficiency? Is there a unique polarization? a difficult phase profile to work with? or something else?
  • Are there specific technology features (i.e., diffraction, polarization, retardation, wavefront, focus, opto-electronics, other) that you are interested in?
  • What are the characteristics of the light source you need to work with (i.e., polarization, bandwidth, collimation, intensity, coherence)?
  • What are the desired characteristics of the light at the output of the system?
  • Are there any specific tests, experiments, or prototypes that would best validate a solution for your problem?
  • What is the timeframe within which you need a demonstrated solution?
  • Are there any unique or challenging form factor requirements? Thickness requirements? Large active area requirements?