Surface-Emitting Laser Assembly for Thermal Interference Control
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Solution Overview
Problem
Conventional Q-switched solid-state lasers face challenges in achieving short pulse widths due to thermal interference between the surface-emitting laser and the solid-state laser medium, leading to decreased oscillation efficiency and conversion efficiency of optical wavelengths, while also being costly and difficult to manufacture with high precision.
Innovation Solution
A laser element with a laminated semiconductor layer, a solid-state laser medium, and a heat exhaust unit that includes a high thermal conductivity material to manage heat generated during operation, ensuring coaxial optical axes and integrated bonding of optical components to prevent thermal interference and enhance productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the length of the solid-state laser medium is reduced to obtain shorter pulse width, then the pulse width is shortened, but the excitation efficiency decreases significantly
Solution Approach 1:
The patent transitions from linear excitation to radial excitation by using a surface-emitting laser that irradiates the laser medium from the side rather than from the end. This dimensional change allows the excitation light to penetrate through the medium more effectively, maintaining high excitation efficiency even when the medium length is reduced for shorter pulse width operation.
Solution Approach 2:
The patent introduces a resin layer as an intermediary between the surface-emitting laser and the solid-state laser medium. This resin layer serves as an optical coupling medium that improves light transmission and ensures stable excitation, enabling the system to achieve both short pulse width and high excitation efficiency simultaneously.
2Use of energy by moving object
If the length of the solid-state laser medium is increased to increase the amount of excitation light absorbed, then the excitation efficiency is improved, but the resonator length increases and pulse width is extended
Solution Approach 1:
By changing from longitudinal excitation to radial excitation, the patent allows the laser medium to be excited efficiently in a shorter length configuration. The surface-emitting laser irradiates the medium from the side, enabling sufficient energy absorption without increasing the medium length, thus maintaining short pulse width while achieving high excitation efficiency.
3Reliability
If conventional Q-switched solid-state laser assembly is used with high-precision positioning of optical elements, then the light source output stability is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent combines the surface-emitting laser, resin layer, and solid-state laser medium into a single integrated laminated structure. This merging eliminates the need for separate assembly and high-precision positioning of multiple optical elements, significantly reducing manufacturing complexity while maintaining output stability through the inherent stability of the laminated configuration.
Solution Approach 2:
The resin layer acts as an intermediary that bonds the surface-emitting laser and laser medium together in a stable configuration. This bonding approach ensures positional stability and optical alignment without requiring complex adjustment mechanisms, simplifying manufacturing while maintaining reliable output.
4Volume of moving object
If the solid-state laser medium and surface-emitting laser are integrated to reduce size, then the device size is reduced, but thermal interference occurs between the two components
Solution Approach 1:
The resin layer serves as a thermal intermediary between the surface-emitting laser and the solid-state laser medium. It provides thermal isolation to prevent heat transfer and thermal interference between the two components, while still maintaining optical coupling for efficient excitation. This allows compact integration without thermal problems.
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 allows for the generation of short-pulse lasers with improved oscillation efficiency and conversion efficiency, reducing thermal interference and manufacturing complexities, resulting in a more reliable and cost-effective laser element.
Implementation Method 1
a heat exhaust unit that is disposed between the laminated semiconductor layer and the laser medium, and exhausts heat generated in at least one of the laminated semiconductor layer or the laser medium
Implementation Method 2
a first resonator that causes light of the first wavelength to resonate between the first reflection layer and the third reflection layer
Implementation Method 3
a second resonator that causes light of the second wavelength to resonate between the second reflection layer and the fourth reflection layer
Implementation Method 4
an active layer that performs surface emission at the first wavelength
Implementation Method 5
a decrease in the conversion efficiency of the optical wavelength in the solid-state laser medium
Data Source
AI summary
To prevent a decrease in oscillation efficiency of laser light and a decrease in conversion efficiency of an optical wavelength due to thermal interference. A laser element includes: a laminated semiconductor layer including a first reflection layer with respect to a first wavelength and an active layer that performs surface emission at the first wavelength; a laser medium disposed on a rear side of an optical axis of the laminated semiconductor layer and including a second reflection layer with respect to a second wavelength on a first surface facing the laminated semiconductor layer and a third reflection layer with respect to the first wavelength on a second surface on a side opposite to the first surface; a fourth reflection layer with respect to the second wavelength disposed on the second surface or disposed on a rear side of the optical axis with respect to the second surface; a first resonator that causes light of the first wavelength to resonate between the first reflection layer and the third reflection layer; a second resonator that causes light of the second wavelength to resonate between the second reflection layer and the fourth reflection layer; and a heat exhaust unit that is disposed between the laminated semiconductor layer and the laser medium and exhausts heat generated in at least one of the laminated semiconductor layer or the laser medium.