Fun with VCSELs

My wife and I recently purchased new iPhone 8’s, after we debated if we should wait for the iPhone X or not. In the end, I decided that the iPhone 8 had the majority of the new technology of the iPhone X minus the OLED screen and at a $200 – $300 discount price to that of the iPhone X. While the displays on OLED phones are beautiful, that price premium was a bit hard for me to swallow.

I’m not one to always have to have the newest iPhone, but at the same time, iPhones, like most technology in general, ages over time, and there can be a cost to maintaining older technology. After 3 years, the battery life on our iPhone 6’s was getting limited, and Apple charges $80 for a replacement battery.  Something tells me all along that Apple had designed its iPhone batteries to fail just about the time when another iPhone was launching. How convenient. 🙂

In the past, I have written about some of the laser applications used to produce a modern smartphone. For example, Coherent’s excimer laser production is currently running at full capacity so as to deliver enough lasers so that OLED fabs can make enough OLED screens for the iPhone X.  Samsung and others, including Chinese smartphone manufacturers also make phones with OLED screens, which has put lots of demand on Coherent to make enough excimer lasers.

The iPhone 8 does not have an OLED screen, but it still takes many lasers to manufacture this phone, including the excimer lasers it takes to make the active LED screens. But the iPhone 8 is also notable because it is the first iPhone that contains lasers, two to be exact. The iPhone 8 contains a lower-power VCSEL (Vertical-Cavity Surface-Emitting Laser) pointing backward and another higher-powered VCSEL facing forward. If you own an iPhone 8, you are holding these lasers in your hand right now but probably never knew it.

In 2013 Apple acquired an Israeli company named PrimeSense, which produced the technology in the first Microsoft Kinect sensor. Then earlier this year, Apple bought another Israeli startup called RealFace. It is believed that Apple incorporated laser technology it had acquired from PrimeSense in the 3D laser scanner it incorporated on the front and back of the iPhone 8. It is also believed that RealFace technology was to be used in a facial security system that could have replaced the fingerprint Touch ID, but apparently it wasn’t working well enough to be included in the iPhone 8, at least at the launch. Rumors of Apple ditching the home button in favor of a fingerprint sensor incorporated into the touchscreen also came to pass.

If the front and rear-facing laser sensors on the iPhone 8 don’t recognize faces, what do they do? First, they assist the iPhone 8’s camera to understand the scene the camera is viewing, and they assist with camera autofocusing. Second, the laser sensors assist virtual reality applications to understanding their physical environment, in the same way autonomous vehicles use LIDAR and cameras to understand their physical environment.

iPhone virtual reality applications are limited at this point, but Ikea has released an interesting one that gives you some idea of the iPhone 8’s VR capability. The application lets you take Ikea virtual furniture and see how it would look in your “real room.” The Ikea application works well, and I can see many more retailers producing these applications so you can see how their virtual wares will fit into your physical life.

Lumentum is producing the majority of the VCSELs that Apple is using in their iPhones, but Apple will also buy some additional VCSELs from other manufacturers like Finisar and II-VI.

While the iPhone 8 is the first Apple smartphone using VCSELs, they have been used in a variety of other smartphones for several years now. The LG G3 contained a VCSEL autofocus system back in 2014, and today a variety of Android smartphones contain VCSEL autofocus systems.

VCSELs have been used in many applications outside of smartphones, including computer mice, and automotive LIDAR systems, but smartphones represent a large opportunity for these lasers. They also should provide smartphone users with a variety of new smartphone features, and for smartphone manufacturers, VCSELs are low-cost and quite small, which is very important for a smartphone.

I track VCSEL uses and applications, and hope to cover them more in future blogs. These versatile low-cost little lasers have a very bright future ahead, and you are sure to see them in many more applications going forward.

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