Bidirectional Electrically Switched Laser

Operation of a double-rooftop ruby laser emitting along directions that are at an angle of 17.45° with respect to one another has been investigated. The ruby is a 3.17-cm cylinder with a 17.45° chisel at each end, one of which is silver-coated. The other end has an antireflection coating, so that external dielectric (or silver) reflectors complete two separate Fabry–Perot cavities, which have about one-third the active medium in common. A polarizer and nitrobenzene Kerr cell in each path allow fast switching from one axis of emission to the other; the switching has been accomplished within 1 μsec in the present experiment. Some implications of the experiment with regard to more general problems of laser deflection are also discussed.