Ce:YAG Fluorescent Light Source for High-Radiance Fiber Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current broadband incoherent light sources, such as LEDs, are unsuitable for providing high-radiance illumination to optical fibers due to their low radiance and inability to produce narrow beams, which are necessary for biomedical and imaging applications like optogenetics.
Innovation Solution
A broadband high-radiance optical source is developed using a doped material, like Ce:YAG, that fluoresces when stimulated by laser diodes, with a light-concentrating cavity and heat sink for efficient light collection and thermal management, allowing for high-intensity broadband light emission suitable for optical fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If broadband LEDs are used for illumination, then broadband illumination is provided, but radiance is low and beam narrowness is insufficient
Solution Approach 1:
The patent combines multiple functional elements into an integrated LED assembly: the broadband LED, laser diode for stimulation, light-concentrating cavity with reflective material, and heat sink are merged into a single compact unit. This merging achieves high radiance through efficient light concentration while maintaining compactness, resolving the contradiction between illumination intensity and device complexity.
Solution Approach 2:
The invention introduces a light-concentrating cavity that transforms the spatial distribution of light from the LED. By using reflective surfaces arranged in a specific three-dimensional geometry, the cavity concentrates omnidirectional LED emission into a narrow directional beam, achieving high radiance without increasing overall device size.
2Illumination intensity
If broadband LEDs are used, then broadband illumination is achieved, but beam narrowness is insufficient for optical fiber coupling
Solution Approach 1:
The light-concentrating cavity employs curved reflective surfaces that redirect light rays through controlled reflection. The spherical or parabolic geometry of the cavity surfaces focuses divergent LED light into a narrow convergent beam, enabling efficient coupling to optical fibers while maintaining broadband illumination characteristics.
3Illumination intensity
If high-intensity illumination is provided, then radiance is improved, but thermal management becomes difficult
Solution Approach 1:
The heat sink is integrated directly with the LED assembly, merging thermal management functionality with the light-generating structure. This combination allows efficient heat dissipation from the high-intensity LED source, enabling sustained high-radiance operation without excessive temperature rise.
Solution Approach 2:
The heat sink acts as an intermediary thermal management component between the LED and the environment. It provides a controlled thermal pathway that conducts heat away from the LED junction, preventing overheating while maintaining the compact integrated design of the assembly.
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 solution provides a compact, high-radiance broadband light source capable of efficiently coupling light into optical fibers, addressing the limitations of existing technologies by achieving high-intensity illumination with efficient thermal management and modulation capabilities.
Implementation Method 1
a body formed from a doped material that fluoresces when stimulated at a stimulus wavelength
Implementation Method 2
The light-concentrating cavity may be formed on the sides of the body by attaching or depositing a reflective material
Implementation Method 3
at least one side of which may also provide a heat sink for cooling the body
Data Source
AI summary
A high-radiance broadband incoherent light source is provided by pumping a body formed from a doped material, such as a Ce:YAG crystal with one or more laser diodes. The laser diodes emit at a stimulus wavelength, which may be an absorption wavelength of the body, and the body fluoresces to emit broadband light in a wide emission band. The body is either disposed in, or forms a light-concentrating cavity, e.g., reflective surfaces, which may be dichroic surfaces, can be formed on or attached to the sides of the body to concentrate the emitted light. The light is captured by a light collector that is coupled to an output face of the body to produce a broadband illumination beam. One or more of the reflective surfaces forming the light-concentrating cavity may form a heat sink.