Clues in the Altocumulous

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

Clouds — those mesmerizing cotton puffs in the sky — cover some 70 percent of the earth’s surface at any given time. While they’re made up of mere water droplets and tiny ice particles, their complexity is reflected in their swift formation and dispersion, and rapidly changing hues.

For scientists, clouds represent the biggest source of uncertainty when it comes to understanding climate change. Are they accelerating warming or cooling the earth? Or both?

That mystery has prompted current and upcoming satellite missions from the world’s space agencies to incorporate lidar and other photonics technologies to help profile clouds and their cousins, aerosols — suspensions of sand, volcanic ash or other materials that scatter and absorb sunlight. Beyond lidar, sophisticated new sensors are tracking absorption lines throughout the infrared spectrum, extracting highly accurate atmospheric temperature and water vapor changes, as just one example. Read article for “Space-Based Remote Sensing Yielding New Insights into Climate Change.”

In keeping with our remote sensing theme, senior editor Justine Murphy previews this month’s SPIE Defense + Commercial Sensing Conference to be held April 17-21 in Baltimore. Billed as “the leading global sensing and imaging event for commercial applications,” the must-attend event covers advances in cameras, high-precision optics, fiber sensors, spectroscopy, IR detectors and more (read article).

Before we turn from remote sensing, don’t miss “New Indium Antimonide-Based IR Detectors Surpass Previous Limitations”, by IRCameras’ Arnold Adams, Len Kamlet and Elliott Rittenberg (read article). Advancements in the production of InSb focal plane arrays are extending the wavelength response of today’s cameras below 3 µm.

Also in this issue, Uwe Vogel of the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, explores the expanding market for OLED microdisplays, and offers an overview of recent technical advances, from subpixel patterning to the development of stacked OLEDs. Vogel’s “OLED Microdisplays: Advancing Virtual and Augmented Reality Smart Glasses” (read article).

Finally in this month’s print exclusive, contributing editor Marie Freebody’s “Delivering Optical Devices to the Medical Market” (read article) recounts the opportunities and potential pitfalls of commercializing medical devices that integrate optics or photonics technologies. It’s not enough to answer an unmet need; device manufacturers must account for clinical trials and lengthy regulatory approvals. Yet with a global market that is expected to reach $538.7 billion in 2018, according to BCC Research, fueled by an explosion in wearable devices, there may never be a better time to enter the market than now.

Enjoy the issue.