Waveguide Laser Thermal Lens Control via Segmented Heat Sink
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Solution Overview
Problem
Conventional mode control waveguide-type laser devices have a limited control range for the focal distance of the thermal lens due to the determination of the excitation region and heat sink tooth spacing based on required laser power, which restricts heat dissipation and lens control.
Innovation Solution
A mode control waveguide-type laser device with a planar laser medium and a heat sink bonded via a cladding, where the refractive index distribution is adjusted by generating a desired temperature distribution, allowing heat to be dissipated across the surface where it is generated and creating a thermal lens where it is needed, thereby broadening the focal distance control range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the excitation region and heat sink tooth spacing are determined based on required laser power, then the laser device can achieve the required power output, but the control range of the thermal lens focal distance is limited
Solution Approach 1:
The heat sink is divided into multiple independent teeth structures, allowing selective bonding to the cladding. This segmentation enables independent control of heat dissipation regions, creating different temperature distributions and refractive index profiles in the laser medium, thereby achieving variable thermal lens focal distances while maintaining required power output.
Solution Approach 2:
The patent makes the thermal lens focal distance adjustable by dynamically changing the bonding area between heat sink teeth and cladding. By varying the bonded area, the temperature distribution in the laser medium changes, which dynamically adjusts the refractive index distribution and thus the thermal lens focal distance, providing adaptability without sacrificing power output capability.
2Adaptability or versatility
If heat is dissipated from limited regions, then the thermal lens focal distance can be controlled within a narrow range, but heat dissipation efficiency is reduced
Solution Approach 1:
Different regions of the heat sink teeth are selectively bonded to the cladding, creating local variations in heat dissipation. Some regions have full bonding for efficient heat removal, while other regions have partial or no bonding to maintain temperature gradients for thermal lensing. This local quality differentiation simultaneously improves heat dissipation efficiency and enables thermal lens focal distance control.
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
This approach enhances the reliability of the laser device by allowing adjustable refractive index and lens effects within the laser medium, enabling effective heat dissipation and thermal lens creation, thus improving the control over the focal distance.
Implementation Method 1
The excitation light entering from the end surface 105a of the laser medium 105 is absorbed in the laser medium 105 to generate gain with respect to the laser light inside of the laser medium 105
Implementation Method 2
A total reflection coating that reflects laser light is provided on an end surface 105a on the incident side of the laser medium 105
Implementation Method 3
an anti-reflection coating that reflects a part of laser light and transmits a part thereof is provided on an end surface 105b on the exit side
Implementation Method 4
a heat sink 102 bonded with a bonding agent 103 onto the lower surface of the cladding 104
Implementation Method 5
the laser medium 105 has a waveguide structure in a thickness direction (y axis) of a cross section perpendicular to an optical axis 106 (z axis) representing a laser oscillation direction, and has a cyclic lens effect in a direction (x axis) perpendicular to the optical axis 106 and the thickness direction
Implementation Method 6
The laser medium 105 is planar and has a waveguide structure in a thickness direction (y axis) of a cross section perpendicular to an optical axis 106 (z axis) representing a laser oscillation direction
Data Source
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AI summary
Provided is a mode control waveguide-type laser device with a broadened control range of the focal distance of a generated thermal lens and with improved reliability. The mode control waveguide-type laser device includes: a laser medium which is planar and has a waveguide structure in a thickness direction of a cross section perpendicular to an optical axis (6), for generating gain with respect to laser light; a cladding bonded onto one surface of the laser medium; and a heat sink (2) bonded via the cladding onto the one surface side of the laser medium. The laser medium generates a lens effect due to a refractive index distribution, and the laser light oscillates in a waveguide mode in the thickness direction, and oscillates in a spatial mode due to the lens effect in a direction perpendicular to the optical axis and the thickness direction. The refractive index distribution within the laser medium is created by generating a desired temperature distribution in the laser medium depending on a junction area of the cladding and the heat sink (2) .