Patent ID: 7457341

Claim:
A semiconductor pump laser comprising: a semiconductor chip having a first facet at one end thereof and a second facet at the opposite end thereof; an optical waveguide between the first facet and the second facet, comprising an active layer sandwiched between a n-type layer and a p-type layer to form a diode, wherein the optical waveguide and the first and second facets form an optical cavity capable of supporting multiple lasing modes, wherein the cavity has a cavity length that is between about 800 micron and 3000 micron; a single metal electrode in contact with a p-side current injection area extending along the optical waveguide for pumping a drive current into a pumped area of the active layer; a grating extending from the first facet to the second facet within the waveguide to provide distributed feedback for a plurality of adjacent lasing modes, wherein the grating is coupled to the active layer at a total coupling coefficient—cavity length product not exceeding 0.2.