Framework for optimizing AR waveguide in-coupler architectures

Waveguide displays have been shown to exhibit multiple interactions of light at the in -coupler diffractive surface, leading to light loss. Any losses at the in -coupler set a fundamental upper limit on the full -system efficiency. Furthermore, these losses vary spatially across the beam for each field, significantly decreasing the displayed image quality. We present a framework for alleviating the losses based on irradiance, efficiency, and MTF maps. We then derive and quantify the innate tradeoff between the in -coupling efficiency and the achievable modulation transfer function (MTF) characterizing image quality. Applying the framework, we show a new in -coupler architecture that mitigates the efficiency vs image quality tradeoff. In the example architecture, we demonstrate a computation speed that is 2,000 times faster than that of a commercial non -sequential ray tracer, enabling faster optimization and more thorough exploration of the parameter space. Results show that with this architecture, the in -coupling efficiency still meets the fundamental limit, while the MTF achieves the diffraction limit up to and including 30 cycles/deg, equivalent to 20/20 vision.