Near-infrared digital heating solutions with power VCSEL arrays

Thermal processes play an essential role in the production and processing of countless industrial and consumer products. Narrow bandwidth near infrared (NIR) light allows contactless transfer of energy with a high power per area that can be tailored to the needs of the application. With arrays of VCSELs (Vertical-Cavity Surface Emitting Laser diodes), NIR emitters can be realized that provide heat where and when it is needed, with a high power conversion efficiency. A scalable system comprises emitters as well as electronic drivers and software, allowing spatial- and time resolved heating profiles of almost arbitrary dimensions. Application tests have shown that for fast firing of solar cells such compact systems can replace bulky belt ovens and achieve benchmark cell efficiencies with unprecedented heating rates of >1000 K/s.