MTF Analysis of Augmented-Reality Waveguide Devices

Grating-based waveguides have come to dominate the field of Augmented & Mixed Reality (AR & MR). The ultimate test of these devices is to obtain a good reconstruction of the digitally generated image at the retina of the user of the device. This aspect of the performance is typically characterized through the modulation transfer function (MTF), which quantifies the resolution capabilities of an imaging system. Unlike eye-box uniformity (another vital measure of the quality of an augmented reality gadget, since low uniformity can cause extremely uncomfortably strobing and flickering effects), the MTF is extremely sensitive to the temporal coherence properties of the source as well as any diffraction which may evolve, not just in the last propagation step to the retina (a given, since we are propagating into a focus), but also, crucially, also diffraction that evolves upon propagation inside the waveguide (typically caused by truncations at the boundaries of grating regions).

The optical modeling and design software VirtualLab Fusion provides the perfect tools to face these challenging design tasks. The flexibility provided by its pool of modeling techniques, implemented on a single software platform for maximum seamlessness in their interoperability, allows the optical designer to strike the necessary balance between accuracy and speed each time – with simulations that are as accurate as needed, and as fast as possible. If you still need convincing, go ahead and take a look at the examples below!

Control of Accuracy-Speed Balance for MTF Analysis in Complex Waveguide Devices for AR-Applications

In this use case we show how temporal coherence of the source and diffraction upon propagation inside the waveguide are effects which must be taken into account in the model when characterizing the PSF & MTF of a grating-based waveguide for application in the AR & MR field.

Construction of a Light Guide

Light guides with coupling gratings can be set up in VirtualLab Fusion using the Light Guide component and its flexible region definition.

Train Your Optic Design Skills This Summer | Live in Jena

Train Your Optic Design Skills This Summer | Live in Jena