special issue

ilio Segrè Visual Archives; Mehau Kulyk/Science Photo Library; Martin Dohrn/Science Photo Library; Shuji Nakamura; Massachusetts Institute of Technology; Adam R ContosLight fantasticThe laser has become so ubiquitous that it would be impossible to acknowledge everyonewho has played a role in its success. As Roy Glauber said at the 2005 Nobel-prizebanquet, when it comes to lasers, “many hands make light work”. And he should know:the prize Glauber shared with fellow optics pioneers John Hall and Theodore Hänsch isone of more than 10 Nobels awarded (so far!) for laser-related research. This timelinemarking 50 years of the laser contains Physics World’s pick of events from laser history,including prizes (gold text), applications (green) and “firsts” (blue).A team led by Charles Townes builds the first “maser”, a forerunner of thelaser that had been described theoretically (and independently) byNikolay Basov, Alexander Prokhorov and Joseph Weber in 1952. Basov,Prokhorov and Townes share the 1964 Nobel Prize for Physics for their workon the “maser–laser principle”Gordon Gould coins the term “laser” in his lab notebook. The entry becomesthe basis of a 30-year patent disputeTheodore Maiman builds the first functioning laser, observing lasing actionin a crystal of pink ruby (16 May)William Bennett, Donald Herriott and Ali Javan invent the helium–neon gaslaser, the first to produce a continuous beam of laser light (12 December)Charles Campbell and Charles Koester perform the first laser surgery, destroyinga human patient’s retinal tumour using a ruby laserRobert Hall invents the semiconductor diode laserLasers are used to align a subway tunnel beneath San Francisco BayDennis Gabor wins the Nobel Prize for Physics for developing holographyThe first large-scale laser light shows are stagedMilitary laser target designators are used for the first time, during theVietnam WarFirst trials of laser supermarket bar-code scannersJohn Madey invents the free-electron laser195019531957196019611962196619701971197219741976