a ultraviolet curing epoxy designed for use in optical assemblies was used to attach the sensitive material to the optic fiber it is sold under the tradename of norland optical adhesive 61 norland products new brunswick n j the laser utilized was a commercial neodymium glass laser with a wavelength of 1 05 micrometers pulse energy and length were about 9 joules into the fiber in about 10 milliseconds the pulse energy and pulse length were both much more than required since the black powder ignites in about 0 5 millisecond or less laser light was focussed into the fiber optic with a 2 inch focal length lens the sensitive material used was black powder with a typical maximum dimension of 2 to 3 millimeters with a mass of approximately 10 milligrams the system was assembled by placing drops of the epoxy glue on the side of the fiber and placing black powder grains into the glue the glue was cured under a ultraviolet for a period of about several minutes observations were made with linear high speed photography and photomultiplier tubes recording light emission which is indicative of ignition the light signal from one position of a linear photography record is shown in.