Semiconductor Laser Thermal Management via Segmented Peltier Cooling
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Solution Overview
Problem
Current semiconductor lasers face challenges in precise and quick temperature control due to low heat transfer efficiency, leading to unstable wavelength output and mode jumps during wavenumber tuning, as traditional heat sink methods result in poor thermal conduction and convection-based heat dissipation.
Innovation Solution
An optical interference light source device with a heat dissipation plate, ring-shaped semiconductor refrigerating sheet, and a PCB board with thermally conductive silicone grease connections, allowing for controlled heating and cooling, and real-time temperature measurement using an NTC thermistor, enhancing thermal conductivity and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a traditional heat sink is used to control the temperature of the semiconductor laser, then the structure is simple, but the heat transfer efficiency is low and the temperature control precision is poor
Solution Approach 1:
The heat dissipation system is segmented into multiple functional components: a heat dissipation plate for primary heat absorption, a PCB board with copper areas for heat conduction and electrical connection, and a ring-shaped semiconductor refrigerating sheet for active temperature control. This segmentation allows each component to perform its specific function optimally, resolving the contradiction between structural simplicity and temperature control precision.
Solution Approach 2:
The patent introduces thermally conductive silicone grease as an intermediary substance between the semiconductor laser housing and the heat dissipation plate, and between the refrigerating sheet and the PCB board. This intermediary ensures efficient thermal contact while accommodating minor surface irregularities, significantly improving heat transfer efficiency without complicating the overall structure.
2Stability of the object's composition
If the ambient temperature of the semiconductor laser is changed to stably change the wavelength, then the wavelength can be changed stably, but the heat transfer efficiency is low due to heat conduction inertia of the heat sink
Solution Approach 1:
The patent employs composite material structures: the PCB board combines copper areas (high thermal conductivity) with fiberglass substrate, the heat dissipation plate uses aluminum or copper alloys, and thermally conductive silicone grease is used as a thermal interface material. This composite approach maximizes heat transfer speed while maintaining wavelength stability during temperature control.
Solution Approach 2:
The patent replaces the traditional passive mechanical heat sink system with an active thermoelectric cooling system (Peltier element). This substitution enables rapid and precise temperature control by applying electrical current to the refrigerating sheet, directly addressing the heat generated by the laser and achieving both fast response and wavelength stability.
3Device complexity
If a traditional heat sink with convection heat transfer is used, then the structure is simple, but the heat dissipation efficiency is poor and mode jumps occur during wavenumber tuning
Solution Approach 1:
The patent implements a feedback control system where a temperature sensor (NTC thermistor) continuously monitors the temperature of the semiconductor laser and feeds this information to a control circuit. The control circuit adjusts the current to the ring-shaped semiconductor refrigerating sheet in real-time to maintain the laser at the desired temperature, preventing mode jumps and ensuring operational stability while keeping the structure relatively simple.
Solution Approach 2:
The patent replaces passive convection-based heat dissipation with active Peltier cooling. The thermoelectric refrigerating sheet directly removes heat from the laser diode through solid-state cooling, providing rapid and controllable heat dissipation that maintains operational stability during wavenumber tuning without requiring complex mechanical convection systems.
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 solution provides high temperature control precision, stable output wavelengths, and increased temperature control range, preventing mode jumps by accelerating heat conduction and improving the stability of the semiconductor laser's operating temperature.
Implementation Method 1
a lower end of a housing of the semiconductor laser is connected to the first circular windowed copper area through a thermally conductive silicone grease
Implementation Method 2
a ring-shaped semiconductor refrigerating sheet is provided with a through hole at a center thereof, a refrigerating surface of the ring-shaped semiconductor refrigerating sheet is connected to the first circular windowed copper area
Implementation Method 3
the thermal sensor is provided on the first circular windowed copper area to detect a temperature of the first circular windowed copper area
Implementation Method 4
the heat generated from the semiconductor laser sequentially passes through a welding layer, an insulation layer and the heat sink and is finally dissipated through convection heat transfer
Data Source
AI summary
Provided is an optical interference light source device of a current-temperature controlled semiconductor laser, including a heat dissipation plate, a ring-shaped semiconductor refrigerating sheet, a semiconductor laser, a PCB board, a thermal sensor and a fixed plate. The first circular window copper area of the PCB is in contact with the second circular copper area through a via. A lower end of a housing of the semiconductor laser is connected to the first circular windowed copper area through a thermally conductive silicone grease. The ring-shaped semiconductor refrigerating sheet is connected to the first circular window copper area through a thermally conductive silicone grease connected to the heat dissipation plate. The thermal sensor is configured to detect a temperature of the first circular windowed copper area. The present disclosure has beneficial effects of simple structures, good thermal conductivities, high temperature control precisions, and stable output wavelengths of the laser.