Degradation analysis of secondary lens system and its effect on performance of LED-based luminaire

• The aged polycarbonate lens increases the radiant flux.
• The lens holder degradation is the major contributor to the changes of the optical parameters.
• The degradation of the lens system leads to a significant impact on color maintenance.

Degradation of a secondary lens system and its effect on LED-based luminaire performance are investigated. A polycarbonate plastic lens system is selected as a test vehicle. The lens system is aged under an actual user condition using high power warm white LEDs. The spectral power distributions (SPDs) of the LED/lens assembly are obtained before and after 9500 h of continuous operation. A detailed SPD analysis is followed to identify the most critical parameter of the lens system degradation.