Single Photon Image Storage Update

The University of Rochester news release announcing "Ultra-Dense Optical Storage--on One Photon" described in last week's RF Report reached the wrong conclusion about researcher John Howell's work in delaying light. Robert Yankowitz, RF systems manager at CBS in Boston, referred me to the Scientific American article "How Can a Single Photon Produce a Whole Image? Short answer: it can't" by JR Minkel. The University of Rochester news release has been pulled from its Web site, although a cached version remained available through Google and at

Another page on the University of Rochester Web site features the story "Ultra-Sensitive Measurement of Changes in Images" by Daniel Richman and Lois H. Gresh, which offers a more scientific description of the experiment using the same graphics but noting that the image was stored using 2 ns long pulses of light at 7 ns intervals. The incorrect reference to "single photon" in the University's original news release appears to have been a misinterpretation of the research team's use of a single pulse of light.

The results are still intriguing and readers will probably appreciate the more detailed description of the work in "Ultra-Sensitive Measurement of Changes in Images."