Wednesday, March 2, 2011
Shaped pulses make opaque film see-through: The team achieved this through a trial and error process. They used a liquid crystal device which allows precise control of light, called a spatial light modulator (SLM), to manipulate 64-femtosecond-long laser pulses being projected onto a layer of paint. A detector measured the intensity and duration of the pulses that emerged from the other side. This information was then passed to a computer program that used it to tweak the SLM to make the next pulse arriving at the detector both brighter and less spread out in time.