Semiconductor Lasers For 3-D Sensing

The November 2017 release of Apple’s iPhone X, with its “Face ID” authentication by facial recognition, highlighted the disruptive potential of 3-D sensing via mobile devices—a technology that could ultimately find use in hundreds of millions of smartphones worldwide. The sudden transition in 3-D sensing in mobile devices has stoked unprecedented demand, and a new market, for vertical-cavity surface-emitting lasers (VCSELs); and, more generally, for the GaAs/AlGaAs near-infrared semiconductor lasers at the heart of these systems. And while semiconductor edge-emitting lasers (EELs) already serve traditional industrial and telecom markets, their fastest future growth could come in 3-D sensing, with the lion’s share going toward mobile electronics.

Compact, efficient, and featuring narrow and stable linewidths (in contrast to the familiar LED light sources already embedded in smartphones), the current generation of GaAs/AlGaAs semiconductor lasers fit the needs of this burgeoning market, as well as other core areas such as autonomous-vehicle sensing. But which of these diode lasers are best suited for which job? In this article, we provide an overview of the key attributes of diode lasers deployed in today’s consumer devices and an update on their state-of-the-art capabilities.

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