Tunable coherent infrared techniques show progress

Recently several groups have produced tunable coherent infrared sources; some of these sources are tunable over a broad range of wavelengths. They vary in their ability to be continuously tuned. The most novel of these sources was reported by James J. Wynne in an invited paper at the Washington meeting of the American Physical Society on 23 April. Wynne, Peter Sorokin and John Lankard, all of IBM Research Center, reported that they had produced a continuously tunable source over the range 2–24 microns with no apparent fundamental limitation to achieving longer‐wavelength generation. Groups at MIT National Magnet Laboratory, Bell Laboratories, Rice University and the University of California at Berkeley have all recently reported on tunable coherent infrared sources.