In the course of writing a feature for this issue on the inroads that quantum cascade lasers are making into the medical arena, I was reminded once again of the many hurdles that new technologies (and devices that employ them) face on the track from bench to bedside. Not only must a technology be proven viable – and viable for targeted applications – but it must also face myriad challenges not specifically related to the technology. In explaining a potential application for QCLs in diabetes detection, Dr. Federico Capasso expressed part of the challenge when he said that “any such tests would have to be FDA approved. What is needed is a lot of research, with doctors and biologists teaming up with QCL researchers and developers.” Capasso is a Harvard professor and part of the team that 20 years ago first demonstrated the quantum cascade laser at Bell Labs. With a QCL-based microscope platform now on the market, Daylight Solutions is well positioned to talk about both the technology and the market challenges. Matt Barre, business development manager for the California company, said the instrument faces other hurdles “related to validation of the technique involving large-scale trials, establishing standards, generating databases, etc.” The microscope platform will allow medical professionals to experience “the power of the technique,” Barre said. Read the article, “QCLs for Medicine: The Promise and the Payoff,” beginning on page 34. And for a look at how another technology – photoacoustics – is making inroads in medicine, see “Photoacoustics Applications Expand Beyond Cancer,” by Managing Editor Laura S. Marshall, starting on page 22. Fans of QCLs will find more on the subject there, where Dr. Werner Mäntele of Johann Wolfgang Goethe University in Frankfurt explains how the high laser power available from QCLs has given photoacoustics increased sensitivity, which will in turn open up more applications for the technology. Also in this issue, contributing editor Marie Freebody talks about the hurdles to clear before terahertz spectroscopy can find commercial success in “Challenges Not Insurmountable for Terahertz Spectroscopy,” beginning on page 26; and Barbara Foster of The Microscopy & Imaging Place Inc. describes how more complex biology experiments are demanding multiple wavelengths in tunable formats in “Microscopy Light Sources Illuminate Research Biology,” starting on page 29. And if you have an interest in microscopy light sources, check out our recent webinar with researcher Dr. Aaron Slepkov of Trent University in Ontario, Canada. You can find the archived version of “Light Sources for Stimulated Vibrational Microscopy” at www.photonics.com/webinars. Enjoy the issue.