Helium producer and supplier Air Products and Chemicals Inc. of Lehigh Valley, Pa., has announced that it is increasing the price of liquid and gaseous helium by 18 percent. Helium is employed in photonics as a laser gas, as a heat transfer agent for the production of fiber optics and as a shielding gas for welding. The company cited a predicted worldwide shortage of helium through 2005.In May 2000, the National Research Council reported that helium prices were low and supplies high. Congress empowered the council in 1996 to oversee the elimination of the National Helium Reserve in Amarillo, Texas.