Cone Laser Gain Module for Diverging LED and LD Pump Light
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Solution Overview
Problem
High-power light-emitting diodes (LEDs) and laser diodes (LDs) emit highly diverging light, making it difficult to efficiently pump laser rods due to a mismatch in emission areas or volumes, resulting in poor conversion efficiency of LED light into laser radiation.
Innovation Solution
A cone laser-gain module with cone-shaped internal reflecting structures that align parallel to the laser emission axis, concentrating and reflecting diverging pump light onto a laser rod for efficient amplification and oscillation, utilizing both end and side pumping methods to increase gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If LED or laser diode is used as pump light source, then the device complexity is reduced and cost is lowered, but the pump efficiency deteriorates due to highly diverging light and area mismatch
Solution Approach 1:
The cone structure is divided into multiple reflective surfaces (first reflective surface on the side wall, second reflective surface on the bottom) that work together to redirect diverging pump light onto the laser rod. This segmentation of the reflective function across different surfaces enables efficient light concentration from LED/LD sources without requiring complex optical systems.
Solution Approach 2:
The cone structure acts as an intermediary optical element between the LED/LD pump source and the laser rod. It mediates the transformation of highly diverging pump light into concentrated light on the laser rod through its reflective surfaces, solving the area and divergence mismatch problem.
2Loss of energy
If conventional pumping method is used, then the pump efficiency is high, but the adaptability to diverging light sources deteriorates
Solution Approach 1:
The cone structure with its specific reflective geometry serves multiple functions: it concentrates diverging light from LED/LD sources, redirects light from different angles onto the laser rod, and maintains pump efficiency. This universal design enables the system to adapt to various diverging light sources without requiring source-specific optical components.
Solution Approach 2:
The cone structure utilizes three-dimensional geometric shaping to solve the two-dimensional area mismatch problem. By creating a volumetric cone geometry with reflective surfaces oriented in multiple directions, it effectively captures and redirects diverging light from a large-area source onto the small-area laser rod through spatial transformation.
3Loss of energy
If anti-reflection coating is applied to laser rod ends, then the optical loss is reduced, but the manufacturing precision requirement increases
Solution Approach 1:
The invention extracts the anti-reflection coating requirement from the laser rod ends by using the cone structure's reflective surfaces to manage optical paths. The cone structure handles the light direction and concentration, eliminating the need for precise anti-reflection coatings on the laser rod ends, thus reducing manufacturing precision requirements while maintaining low optical loss.
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
Effectively concentrates diverging pump light onto the laser rod, enhancing laser gain and amplification efficiency, allowing for the use of man-made diverging light sources like LEDs and LDs for efficient laser pumping.
Implementation Method 1
The pump lights, some of which diverge and initially miss the laser rod, are reflected and concentrated on the laser rod by an inner surface of the cone structure
Implementation Method 2
Optical pumping is one popular scheme, in which, for instance, a diode laser of a first wavelength is focused into a small volume matched to the laser-emission volume in the laser gain medium to efficiently excite the laser radiation and generate a laser of another wavelength
Implementation Method 3
The laser rod with its longitudinal axis parallel to the laser emission axis is disposed on a power-flow path of the pump lights and configured to absorb the pump lights to generate amplified laser lights of another wavelength along the laser-emission axis
Data Source
AI summary
A cone laser-gain module including a pump-light source, a laser rod, and a cone structure, is provided. The cone structure, including a large and a small cone aperture connected by cone axis, is configured to accommodate the laser rod parallel to the cone axis and concentrate the pump light toward the laser rod. The pump light enters the cone structure from a large cone aperture. The laser rod is configured to absorb the pump lights to generate a laser light along a laser-emission axis parallel to the laser-rod axis. In particular, the pump lights, some of which diverge and initially miss the laser rod, are reflected and concentrated on the laser rod by an inner surface of the cone structure. A cone laser amplifier and a cone laser oscillator utilizing single or cascaded cone laser-gain modules are also provided.