They are dissimilar, between ordinary light and stimulated emission. Ordinary light is emitted naturally but light from stimulation is emitted because an atom or molecule is stimulated and it is less efficient than Ordinary light. Physicists try to solve by amplify the light which from stimulated emission. Charles H.Townes is the first to succeed and build a device, Maser but he does not build it from light amplification, It is from microwave amplification. About 1957, Townes and 2 men, Schawlow and Gould write and publish their idea about light wave amplification but Gould files it for a patent first. Until 1987, on one knows that Who owns the idea yet!