Modelling and Thermographic Measurements of LED Optical Power.

Area of Science:

• Engineering
• Optoelectronics
• Thermal Management

Background:

• Accurate measurement of optical power is crucial for light-emitting diode (LED) characterization.
• Existing methods can be complex or require specialized equipment.
• Developing simpler, reliable measurement techniques is an ongoing need in optoelectronics.

Purpose of the Study:

• To present a simple engineering method for evaluating LED optical power using infrared thermography.
• To enable optical power calculation independent of heat transfer coefficients.
• To validate the proposed method against established measurement techniques.

Main Methods:

• Simultaneous measurement of electrical power and temperature for an LED and a reference resistor.
• Utilizing infrared thermography to capture thermal data.
• Comparison with the standard integrated sphere method for validation.
• Thermal resistor network (Rth) and 3D-FEM analysis for confirmation.

Main Results:

• The proposed infrared thermography method accurately estimates LED optical power.
• Results showed consistency with the integrated sphere measurement method.
• The tested LED demonstrated a high optical energy efficiency of approximately 30%.
• Uncertainty analysis confirmed the reliability of the findings.

Conclusions:

• The developed engineering method offers a simple and effective approach for LED optical power evaluation.
• Infrared thermography provides a viable alternative for optical power measurement, especially when integrated sphere setups are unavailable.
• The method's independence from heat transfer coefficients simplifies the experimental procedure and enhances its applicability.