Laser spark plug dream is still alive Thanks for the feature article on laser ignition (“Laser Car Ignition Dream Sparks Multiple Approaches,” September 2012). I worked on laser ignition systems in the early 1980s with PerkinElmer and Sandia National Laboratories, at a time when lasers were so expensive it would have been prohibitive to go beyond proof of concept. But we always knew this would be the future of internal combustion, especially with ethanol, because ethanol can be dyed the same angstrom as the laser light (4912 - 5750 Å), permitting an amazing amount of control over the rate of combustion. Now that computers, control boxes and burning lasers are dirt cheap, I’m surprised it’s taken this long for the auto industry to come around. Maybe the promise of increased fuel efficiency dampened the enthusiasm of old-timers. Let’s hope those days are behind us. We could have had laser ignition 30 years ago, at least in racing, where cost would have been no object. The reason PerkinElmer was interested was because, at the time, it also owned the laser company Spectra-Physics and built the gas chromatographs that monitored the ethanol fuel mixtures used at the Indy 500. Sandia classified all the laser combustion research and wouldn’t even share the final results with its own teams. The reply I got when I asked why was, “You know why!” Remy Chevalier, Web Editor Electrifying Times Erratum Due to an editing error, the Milestones item on Guernsey Coating Laboratories that appeared on page 19 of the April 2013 issue was inaccurate. The company began with one 18-in. vacuum system focusing on just a few applications, such as MgF2, enhanced aluminum and bare aluminum, with each substrate individually inspected, cleaned and evaluated.