Latest applications note

February 27th 2018

We have added a new applications note on the Ar gas cluster depth profiling and quantification of layer composition in compound semiconductors.  Devices that contain distributed Bragg reflectors: alternating layers of high- and low refractive-index material (typically GaAs/AlxGa1-xAs) to create a stop-band where a very particular set of wavelengths are almost fully reflected (ideally over 99.9%). Here we demonstrate the characterisation of a vertical cavity surface emitting laser (VCSELs), tiny (low-cost) semiconductor lasers that use a pair of DBRs to form the mirrors of the lasing cavity. In VCSELs, the quality and consistency of the DBRs is important, as a VCSEL has a gain length on average 105 times smaller than an edge-emitting laser, and therefore needs ultra-high reflectivity mirrors to achieve a reasonable threshold current.