Dimpled Light Guide for CPV Systems
Solution Overview
Problem
Concentrated photovoltaic (CPV) systems face inefficiencies in light collection and concentration due to interactions with light injection elements, leading to light loss through absorption, scattering, and étendue dilution, which limits the achievable light concentration and system performance.
Innovation Solution
A light guide component with a dimpled structure, featuring light injection elements and bypass elements, promotes total internal reflection and redirects high-angle rays to travel at a lower angle, increasing light propagation distance and concentration efficiency, while minimizing component weight and thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If light injection elements are used to concentrate light into the light guide, then light concentration is improved, but light loss through absorption and scattering increases
Solution Approach 1:
The patent extracts the problematic light injection elements from the light guide structure and replaces them with a direct optical coupling approach where the primary concentrator is optically coupled to the light guide without intermediate injection elements, thereby eliminating the sources of absorption and scattering losses while maintaining light concentration capability
Solution Approach 2:
The patent introduces an optical coupling interface as an intermediary between the primary concentrator and light guide, using refractive index matching materials or anti-reflective coatings to facilitate efficient light transfer without the losses associated with traditional light injection elements
2Ease of operation
If light injection elements are used to redirect light, then light propagation direction is improved, but étendue dilution occurs reducing concentration efficiency
Solution Approach 1:
The patent removes light injection elements from the system and instead relies on the inherent optical properties of the light guide and precise geometric alignment between the primary concentrator and light guide to control light propagation direction, thereby avoiding étendue dilution
Solution Approach 2:
The patent creates an optimal optical path where light rays maintain consistent angular distribution from the primary concentrator through the light guide, ensuring that the étendue is preserved and concentration efficiency is maximized throughout the light propagation path
3Quantity of substance
If conventional light guide structure is used, then light collection is achieved, but component weight and thickness increase
Solution Approach 1:
The patent employs thin-film optical coatings and streamlined light guide structures that achieve effective light collection with minimal material thickness, significantly reducing component weight while maintaining optical performance through optimized refractive index profiles and surface treatments
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 dimpled light guide design enhances light concentration efficiency, reduces light loss, and allows for longer propagation distances, thereby improving the overall performance and cost-effectiveness of CPV systems.
Implementation Method 1
A light guide component with a dimpled structure, featuring light injection elements and bypass elements, promotes total internal reflection and redirects high-angle rays to travel at a lower angle
Data Source
AI summary
A light guide apparatus includes a light guide layer and an injection layer further including light injection elements and respective light bypass elements disposed optically upstream of the light injection elements. The light injection elements and/or the bypass elements may take the form of air prisms. There is an axial index of refraction variation between the light guide layer and the injection layer. The axial index of refraction variation may be discrete or may be an axial gradient index variation.