Passive radiative cooling architecture for high-power optoelectronic packages

Area of Science:

• Optoelectronics
• Materials Science
• Thermal Engineering

Background:

• High-power semiconductor lasers require efficient thermal management, especially in compact TO-can packages.
• Conventional glass windows in these packages have poor thermal conductivity and IR transparency, causing heat buildup and performance degradation.

Purpose of the Study:

• To develop and optimize a thermally and optically transparent polyethylene (PE) film as a substitute for glass windows in semiconductor laser packages.
• To investigate the impact of PE film on thermal dissipation and device performance.

Main Methods:

• Fabrication and optimization of a 100-μm PE film with tailored thickness for enhanced mid-infrared transparency.
• Evaluation of optical transparency at 660 nm and mechanical strength.
• Comparison of thermal performance and device metrics (threshold current, output power, slope efficiency) against glass-covered devices.

Main Results:

• The PE film enabled efficient radiative cooling, reducing window temperature by up to 9.4 °C compared to glass.
• Significant improvements in laser performance were observed, including reduced threshold current, increased output power (approx. 50 mW), and enhanced slope efficiency (0.11 W/A).
• A 7.2 °C cooling advantage was achieved at 80 °C ambient temperature, with sustained modulation bandwidth and improved DCO-OFDM data rates (2.11 Gb/s).

Conclusions:

• The optimized PE film serves as a robust, low-cost, and scalable solution for thermal management in high-power optoelectronic devices.
• This approach effectively enhances device performance and reliability in thermally constrained environments.
• Polyethylene films offer a promising alternative to traditional glass windows for advanced laser packaging.