Laser elements having different wavelenghts formed from one semiconductor substrate

摘要

A set of semiconductor laser elements and manufacturing method. The set of semiconductor laser elements have mutually different oscillation wavelengths, and perform single longitudinal mode oscillation by having periodically varying refractive index within the elements. The set of semiconductor laser elements are formed together from one semiconductor substrate. Duty cycle of a diffraction grating in each element differs from each other corresponding to the oscillation wavelength to realize equal coupling coefficient. Alternatively, a product of coupling coefficient and the length of area in which the diffraction grating is formed or a product of coupling coefficient and the length of the element is made substantially constant. <IMAGE>