Following a post-doctoral fellowship at Pennsylvania, he became a Member of the Technical Staff at Bell Laboratories in Princeton, eventually being appointed Distinguished Member of the Technical Staff. He moved to the faculty of the Physics Department at Case Western Reserve University in 1990 as the Warren E. Rupp Associate Professor of Physics.
Singer has numerous publications and holds two patents.
He is a founder and chairman of the Advisory Committee for Joint Activities of the Optical Society of America and the American Chemical Society and is active in organizing conferences for the Optical Society of America. His main research interests are in nonlinear optical materials and devices.