This week’s EYE ON NPI has frickin’ ceramics with frickin’ lasers on its head – it’s a Wurth Elektronik Vertical-cavity surface-emitting laser (VCSEL) infrared laser emitter (Link) . These pick-and-placeable components look a little like large LEDs, and they sort-of are. Except unlike LEDs, the light wavelength is very narrow band wavelength AND it is ‘coherent’ light (Coherence Physics Link) which means that the emitted waves of light are all in sync.
VCSELs are used pretty much exclusively for creating 3D scanning / Time-of-Flight / LiDAR sensors. For those use cases, you want to bounce light off of a surface and measure how long it takes for the waves to return. LiDARs are, of course, very hip right now, because folks are using them in autonomous robotics, 3D scanning and human identification – think Apple face ID (Wiki Link) or XBox Kinect (Kinect). IR light is invisible to human eyes and is safer than UV light, but still easy enough to work with in electronics. With VCSELs, we don’t need hefty tubes to create coherent light anymore. And the cost of a VCSEL is getting to be on par with a plain LED of the same power capabilities.
We’ve covered all-in-one Time-of-Flight sensors on EYE ON NPI before (Blog Link) – but they use much lower power VCSELs, and are narrow emitters. The Wurth VCSEL is perfect for folks who are doing lower-level engineering, creating their own ToF or infrared-light sensing elements. You’ll need to pair this with a driver and, if doing ToF, a high-speed sensor that can detect the pico-second scale changes in flight-return times.
These could also have some use cases for when you want to bathe an area in IR light and you want a very small package and narrow wavelength compared to LEDs. There’s two versions, model 159353940B1300 (Link) which is 110 degree by 85 degree spread, and the 159353940A6300 (Link) which is 60 degree by 45 degree. Both require a 1 to 2 Amp constant current driver and plenty of heat sinking!
Digi-Key has stock right now of the Wurth VCSELs (Short Link), for immediate shipment! If you order right now, you can measure the Time-of-Flight as under 24 hours..that is, you’ll get it the next day. Hey…that’s basically light speed!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.