PARTICLE COUNTER WITH VERTICAL-CAVITY SURFACE-EMITTING LASER

摘要

An improvement to optical particle counter design using the vertical-cavity surface- emitting laser (VCSEL), giving significant advantages over the existing edge-emitting laser diodes commonly used in optical particle counters. VCSELs have relatively low threshold currents, thus consuming less power and generating less heat than standard semi-conductor laser diodes of the same power output. In addition to lower power consumption, the VCSELs have better sensor resolution, improved reliability, lower temperature sensitivity and higher immunity to mode hopping than the edge-emitting laser diodes. In addition, because VCSEL can be tested at the wafer level, lower cost potentials can be achieved. This overall allows the creation of a more sensitive, higher reliability, lower cost, and smaller package size particle counter.