Continued < Back Searching for a more reliable, less power-hungry alternative to vacuum tubes, Bell Labs invents the transistor, marking the beginning of Western Electric's semiconductor component business. Two Bell Labs innovations, zone refining and ion implantation, pave the way for reliable semiconductor fabrication. The first transistor production line is established in Allentown, Pa., and the following year transistors are used in the telephone network for the first time. Bell Labs develops a photoresist material that becomes the standard way to print circuitry on silicon wafers. Bell Labs invents the laser. Lasers (light amplification by stimulated emission of radiation) revolutionize the communications industry in terms of their use as light sources in fiber-optic transmission systems.   Caption: One of the original photos distributed to the press showing the relative size of conventional vacuum tubes and a point contact transistor. Caption: Western Electric transistor production Caption: New photoresist coatings developed at Bell Labs. Caption: A.L. Schawlow adjusts a ruby optical maser during an experiment at Bell Labs, while C.G.B. Garrett prepares to photograph the maser flash.