Novel processing simplifies VCSEL wavelength tuning

Researchers at the University of California (UCSB, Santa Barbara, CA) have built verticalcavity surfaceemitting lasers (VCSELs) in which individual emission wavelengths in twodimensional (2D) laser arrays can be set predictably. Emission wavelengths are adjustable from 965 to 995 nm by a simple postfabrication method in which each cavity length was accurately fixed by anodic oxidation. Such wavelengthtunable VCSEL arrays are potentially useful for applications in freespace optical interconnects