As Ubiquitous as LEDs?

MICHAEL D. WHEELER, MANAGING EDITOR, michael.wheeler@photonics.com

There’s little doubt that when it comes to autonomous vehicles, the question isn’t if … but when. The high-profile legal battle between this generation’s version of the yellow cab, Uber, and Waymo, the autonomous car unit from Google, only re-affirms this presumption. The dispute centers on lidar, arguably the enabling technology behind autonomous vehicles.

Exactly how lidar systems will be configured in the cars of tomorrow — from the light source to the detectors — remains unanswered. But as Contributing Editor Hank Hogan chronicles in “Semiconductor Lasers Power Up” (read article), such systems will, in all likelihood, incorporate inexpensive and rugged semiconductor lasers, prized for their peak powers, which are critical in determining distance and accurate range information. The prospect of these lasers finding their way into tens of millions of autonomous cars one day, coupled with increased uses in optical communications, could make them as widespread as LEDs.

Speaking of ubiquity, color displays are everywhere — and have been since the cathode ray tube was developed in the mid ’50s. Liquid crystal displays (LCDs) supplanted them a decade ago, relying on LEDs instead of fluorescent tubes as energy-saving and efficient backlighting components. LCD displays remain the most robust technology on the market, but new technologies have emerged as “down-converters.” One is cadmium-based quantum dots, which boast excellent luminescence spanning the entire visible range. But an unconventional alternative — fluorescent proteins — promises a more “eco-friendly approach.” Rubén Costa’s “Quantum Dots, Fluorescent Proteins Vie for Supremacy” (read article).

Elsewhere in the issue:

• CCD time delay integration (TDI) offers the twin advantages of a high dynamic range and lower noise. A novel hybrid sensor design that incorporates both a CCD pixel array and a CMOS structure permits higher readouts, without complex external circuitry — and is ideal for inspecting wafers and printed circuit boards. Don’t miss “Hybrid TDI Sensors Feature Faster Line Rates, Higher Sensitivity,” (read article), by Vieworks’ Junghyun Nam and Wojciech Majewski.

• Marcel Friedrichs and Holger Kreilkamp of the Fraunhofer Institute for Production Technology IPT present an approach that extends the lifetime of molds used with chalcogenide glass, an advance that could prove highly beneficial for the future of high-precision IR optics (read article).

• Finally, the uniformity and consistency of a laser beam are critical to industrial R&D in universities around the world. Ophir’s Dick Rieley presents the case for diagnostic cameras and specialized software in ensuring hot spots and other anomalies aren’t present. Rieley’s “Laser Beam Diagnostics Is a Critical Step in University Research,”(read article).

Enjoy the issue!