VCSEL Technology in the Data Communication Industry: The advantages, challenges and new opportunities that single-mode VCSELs bring in datacom

A VCSEL – vertical-cavity surface-emitting laser – is a semiconductor laser diode with a monolithic laser resonator where the laser beam emission leaves the device in a direction perpendicular to the chip surface. VCSELs combine the high power density and simple packaging of an IRED with the spectral width and speed of a laser. Unlike laser diodes, VCSELs are much less sensitive to temperature fluctuations. The short resonator easily enables single-frequency operation combined with some wavelength tunability. The wavelength of VCSELs may be tuned, within the gain band of the active region, by adjusting the thickness of the reflector layers. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.