Dielectric Light Concentrator for Thermally Isolated Laser Pumping
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Solution Overview
Problem
Current laser pumping technologies face inefficiencies in concentrating light from light-emitting diodes (LEDs) for pumping lasers due to the diverging nature of LED light and the challenge of heat insulation from the laser gain material, which limits pump intensity and efficiency.
Innovation Solution
A laser pumping device and system utilizing a dielectric block with a pump axis, featuring a first and second surface and multiple reflection surfaces, designed to guide and concentrate pump light from LEDs while acting as a heat insulator, using anti-reflection coatings and wedged dielectric structures to enhance light transmission and reduce heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a light-emitting diode is installed close to the laser gain material to increase pump intensity, then the pump efficiency is improved, but the heat from the LED affects the laser gain material and reduces reliability
Solution Approach 1:
The device separates the LED pump source from the laser gain material by introducing a dielectric block as an intermediary medium. The block is divided into a light transmission portion (for optical coupling) and a heat insulation portion (for thermal isolation), effectively segmenting the functional requirements of light delivery and heat management into distinct spatial and material zones.
Solution Approach 2:
A dielectric block serves as an intermediary element between the LED and the laser gain material. This mediator allows optical energy to pass through while blocking thermal energy transfer, resolving the contradiction by providing a material that selectively transmits desired energy (light) while preventing unwanted energy (heat) from reaching the laser gain material.
2Illumination intensity
If geometric reflection structures are used to confine LED pump light, then the light concentration is improved, but the light-volume-to-laser-volume ratio becomes inefficient
Solution Approach 1:
The invention changes the optical parameters of the dielectric block, specifically its refractive index, to enable total internal reflection and light guiding. By selecting a dielectric material with appropriate optical properties (higher refractive index than surrounding media), the system achieves efficient light confinement and concentration without requiring complex geometric reflection structures, thereby improving the light-volume-to-laser-volume ratio.
Solution Approach 2:
The patent replaces mechanical/geometric reflection structures with an optical field-based solution using total internal reflection within the dielectric block. This substitution eliminates the need for complex geometric configurations and achieves superior light confinement through material property optimization rather than structural complexity.
3Illumination intensity
If blue-light light-emitting diodes are converted to luminescent emission in a film material, then the light intensity toward the laser crystal is increased, but most of the LED light is not converted and pump efficiency remains low
Solution Approach 1:
The invention extracts and eliminates the inefficient luminescent conversion layer from the system. Instead of relying on phosphor down-conversion that loses most of the LED light, the patent directly transmits the LED emission through the dielectric block to the laser gain material, taking out the problematic conversion interface and its associated energy losses.
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 effectively increases the brilliance and intensity of the pump light, improving pump efficiency by concentrating LED light onto the laser gain material while effectively isolating heat, thereby enhancing the overall performance of the laser pumping process.
Implementation Method 1
The dielectric block with the pump axis includes a first surface, a second surface, and a plural number of reflection surfaces. The dielectric block is configured to receive the pump light into the first surface, guide the pump light along the pump axis surrounded by the reflection surfaces, and transmit the pump light toward the second surface.
Implementation Method 2
one or an array of low-thermal-conductivity optical dielectrics, which guide and concentrate low-intensity light from light-emitting diodes or laser diodes to generate high-brightness light to pump a laser gain material with higher efficiency and less heat in the laser crystal
Data Source
AI summary
A high-efficiency laser pumping device is provided, wherein a dielectric with or without a tapered aperture is used to accept, guide, and concentrate a pump light toward a laser gain material. Preferably, the dielectric is also a heat insulator between the pump-light source and the laser gain material. The pump-light source includes an array of light-emitting diodes, or an array of laser diodes, or an array of mixed light-emitting-diodes and laser diodes. Preferably, the input and output faces of the dielectric are optically coated with dielectric layers to maximize the pump brightness toward the laser gain material. A high-efficiency laser-pumping system with active cooling apparatus is further provided, wherein a plural number of the optical-guiding and thermal-insulation dielectrics are arranged to receive the pump lights from a plural number of pump-light sources, configured to concentrate all the pump light toward a laser gain material.