Optical Waveguide Stray Light Control via Polarization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Augmented reality glasses suffer from a limited visual field due to a small visual angle, leading to poor user experience, and existing optical waveguide solutions generate excessive stray light, degrading imaging quality.
Innovation Solution
An optical waveguide design featuring a first and second total reflection surface with transflective films and phase retardation films, where the transflective films selectively transmit and reflect light based on polarization states, reducing stray light by controlling the transmission angle and ensuring light is directed towards the target without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If conventional optical waveguide designs are used to expand the visual field, then the visual angle increases, but stray light increases excessively degrading imaging quality
Solution Approach 1:
The patent applies local quality by making different regions of the waveguide have different optical properties. Specifically, transflective films are selectively positioned at certain locations to reflect specific wavelengths while transmitting others, and phase retardation films are placed in specific regions to control polarization states. This localized functional differentiation allows the waveguide to expand the visual field while controlling stray light generation in specific areas.
Solution Approach 2:
The patent changes optical parameters including polarization state, wavelength, and transmission angle to control light propagation. By using phase retardation films to convert linear polarization to circular polarization and back, and by carefully selecting the angle of incidence for total internal reflection, the system expands the visual field while maintaining image quality through precise parameter control.
2Object-generated harmful factors
If transflective films are added to control light transmission angle, then stray light is reduced, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into a single integrated waveguide structure. The transflective films and phase retardation films are combined within one waveguide component rather than using separate optical elements. This integration reduces the overall system complexity while achieving stray light control through the coordinated action of the combined films.
Solution Approach 2:
The waveguide structure uses total internal reflection at the waveguide boundaries to naturally control light propagation paths. This self-service mechanism reduces the need for additional complex control elements, as the waveguide geometry itself contributes to directing light and minimizing stray light generation.
3Reliability
If phase retardation films are used to convert polarization states, then light transmission control is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs asymmetric film arrangements where the first and second phase retardation films are positioned at different locations within the waveguide and have different optical axis orientations. This asymmetric configuration provides built-in compensation mechanisms that reduce sensitivity to manufacturing tolerances, allowing reliable polarization control without requiring extremely precise alignment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The optical waveguide effectively reduces stray light, enhances imaging quality, and increases the visible range, thereby improving the user's experience by ensuring light is transmitted with a sufficient small angle, minimizing interference and improving the overall visual field.
Implementation Method 1
Each of the transflective films may completely transmit light having a first polarization state, half transmit and half reflect light having a second polarization state
Implementation Method 2
a first total reflection surface and a second total reflection surface, disposed opposite to each other
Implementation Method 3
a first phase retardation film, disposed on an inner surface of the first total reflection surface between two adjacent transflective films; and a second phase retardation film, disposed on an inner surface of the second total reflection surface between the two adjacent transflective films
Data Source
AI summary
The present disclosure provides an optical waveguide and an optical device. The optical waveguide includes a first total reflection surface, a second total reflection surface, at least two transflective films, a first phase retardation film, and a second phase retardation film, each of the transflective films being configured to completely transmit light having a first polarization state, half transmit and half reflect light having a second polarization state, so that reflected light having the second polarization state propagates through the second phase retardation film and the second total reflection surface toward a target, thereby ensuring a transmission angle of the light output to the outside of the optical waveguide to be sufficiently small, which effectively solves the problem of the stray light, ensures the imaging quality, and improves the user's experience.