One of the pioneers of laser research and winner of a Nobel Prize in physics, Arthur L. Schawlow, died April 28 at age 77 in Palo Alto, Calif.

Schawlow worked with Charles H. Townes in the 1950s on a device that evolved into a laser. The pair collaborated at Columbia University in New York, where they initially gained recognition for work on the maser, a microwave predecessor of the laser. Their goal was to invent a device that would amplify light the way a maser amplified microwaves.

When they published their findings in 1957, the work sparked an international race to build the first working laser, a feat accomplished in 1960 by Theodore H. Maiman in Malibu, Calif.

During his career, Schawlow worked at Bell Laboratories in New Jersey, where he studied superconductivity, and worked on laser and microwave spectroscopy at Stanford University. In the years that followed, he and Townes would each win a Nobel award. Schawlow shared a Nobel Prize in 1981 with Nicolaas Bloembergen of Harvard University in Cambridge, Mass., for contributions to laser spectroscopy.