Optical Engine Waveguide Coupling With Superluminescent Light
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Solution Overview
Problem
Conventional laser-based multicolor optical engines face challenges in coupling all emitted light into waveguides due to chromatic dispersion and narrow light beams, which impede image quality in portable display devices.
Innovation Solution
An optical engine comprising a first light source with a specific peak wavelength and a superluminescent light source with a different peak wavelength, combined with a light combiner and scanner arrangement, facilitates efficient light coupling into waveguides via a diffractive in-coupling structure without compromising image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional laser light sources are used in optical engines, then image sharpness is improved, but chromatic dispersion in diffractive incoupling structures causes image quality degradation
Solution Approach 1:
The optical engine segments the light source into multiple laser sources, each emitting a specific color (red, green, blue). Each laser source is coupled with its own diffractive incoupling structure optimized for its wavelength, thereby segmenting the chromatic dispersion problem into manageable wavelength-specific components rather than dealing with all wavelengths simultaneously through a single structure.
Solution Approach 2:
Diffractive incoupling structures serve as intermediary elements between each laser source and the waveguide. These structures are specifically designed to couple light at particular wavelengths into the waveguide while compensating for chromatic dispersion effects, acting as mediators that transform the narrow laser beams into waveguide-compatible modes without excessive dispersion.
2Volume of moving object
If laser light sources with narrow beams are used, then form factor is reduced, but coupling efficiency into waveguides deteriorates
Solution Approach 1:
Diffractive incoupling structures act as intermediary optical elements that bridge the mismatch between narrow laser beams and waveguide acceptance modes. These structures diffract and reshape the narrow laser beams into patterns that efficiently couple into the waveguide, maintaining high coupling efficiency while preserving the compact form factor benefits of laser sources.
Solution Approach 2:
The diffractive incoupling structures modify the spatial and angular parameters of the laser beams through diffraction. By changing the beam's wavefront curvature, divergence angle, and spatial distribution, these structures transform narrow laser beams into modes that match the waveguide's acceptance characteristics, thereby improving coupling efficiency without increasing the overall form factor.
3Volume of moving object
If diffractive incoupling structures are used to couple light into waveguides, then device size is reduced, but image quality is impeded due to chromatic dispersion
Solution Approach 1:
The system segments the broadband light handling into wavelength-specific channels, with each laser source and its corresponding diffractive incoupling structure optimized for a narrow wavelength band. This segmentation prevents chromatic dispersion from degrading image quality because each diffractive structure only needs to handle a limited wavelength range where dispersion effects are minimal.
Solution Approach 2:
The diffractive incoupling structures are designed with specific diffraction orders and groove profiles that compensate for chromatic dispersion at their respective operating wavelengths. By optimizing the diffraction parameters for each wavelength, the structures maintain high coupling efficiency while minimizing image quality degradation, enabling compact device design without sacrificing image quality.
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
This configuration enhances light coupling into waveguides, reducing spatial intensity variations and maintaining image quality, thereby enabling smaller and more energy-efficient portable display devices.
Implementation Method 1
a superluminescent light source configured to emit second light having a second peak wavelength different from the first peak wavelength
Implementation Method 2
configured to direct light via the in-coupling structure into the waveguide for propagation in the waveguide by total internal reflection
Implementation Method 3
when utilizing such waveguide-based structures, yet further reductions in display device sizes and masses may be achievable by using diffractive incoupling structures for coupling light into waveguides
Data Source
AI summary
This disclosure relates to an optical engine, a display structure, a display device, and a vehicle. The optical engine comprises an illumination arrangement comprising a first light source configured to emit first light having a first peak wavelength and a superluminescent light source configured to emit second light having a second peak wavelength different from the first peak wavelength.