Effective passivation of laser facets is the key to obtaining
the highest power output of
Quality passivation of the laser facets increases the power threshold of the COD
Edge-emitting laser diodes emit very high optical powers from small emission areas, therefore, the optical intensity at the front facet is extremely high. A lot of heat is created in the front facet, where (in addition to normal operation) large numbers of photons are absorbed by different defects, including dangling bonds, threading dislocations, amorphous native oxides, or in short, high level of surface states defects.
This absorption leads to heating of the semiconductor, which shrinks the LD bandgap, resulting in an ever-increased absorption and a further shrinkage of the bandgap. This thermal runaway process melts the semiconductor in Catastrophic Optical Damage (COD). Increasing the power threshold at which the COD happens is an important goal for laser manufacturers.
Currently, a method that provides the best passivating effect is cleaving laser bars in UHV conditions followed by passivating protection, i.e. ZnSe layer, prior to the deposition of the mirror layers. A significant disadvantage of the approach is the complex and very costly implementation of the cleaving step performed in the UHV.
With our novel solution laser bars are cleaved in-air, after which they are treated with an optimized in-situ cleaning process. Once a good clean facet is obtained, the laser bars are passivated in highly controlled conditions before applying the mirror coatings. This way, we achieve results similar to the best processes currently available in the market at significantly reduced costs.
Kontrox increases photoluminescence emission intensity monitored directly from the laser facet active area indicating the improvement of surface quality enabled by Kontrox.
Turnkey laser passivation equipment
To fast-track technology implementation into our customers' production lines, Comptek has launched a turnkey passivation equipment optimized for edge-emitting lasers.
Integrated with cutting-edge cleaning techniques and our novel, proprietary passivation technology, Kontrox LASE 16 is the first machinery in the market precisely designed and optimized for passivation of laser bar facets.
Consisting of a main, processing chamber and a load lock chamber monitored by a PLC-based process controller, this fully automatic machinery enables high-reliability and seamless operation of multiple processes in a strictly controlled and ultra-clean environment.
The new offering is a result of our in-house technological innovation that is based upon our careful selection of premium system components from reputable European system manufacturers for the Comptek team of technical experts to build the laser passivation equipment optimized for Kontrox processes.