in 1965 charles k. kao and george a. hockham of the british company standard telephones and cables (stc) were the first to show that the loss of intensity in optical fibers could be reduced, making fibers a practical communication medium. they proposed that the defects in fibers available at the time was caused by impurities which could be removed. they pointed out the right material to use for such fibers, such as silica glass which has high purity. this discovery earned kao the nobel prize in physics in 2009.