Patent ID: 7072373

Claim:
A ridge waveguide semiconductor laser diode comprising: a semiconductor substrate, a front facet and a back facet; at least one active layer disposed over said semiconductor substrate and disposed between said front and back facets, said at least one active layer having a surface, and at least one cladding layer disposed over said at least one active layer and disposed between said front and back facets and having a ridge structure part and an underlying remaining part, said remaining part overlying said at least one active layer and having a thickness D, and wherein the laser diode emits a beam of light from its front facet when operated, the beam having a maximum power level substantially at its center and a peripheral edge where the power level of the beam is a fraction 1/e 2 of the maximum power level, wherein “e” is the base of the natural logarithm, the peripheral edge of the beam having a vertical width W as measured at the front facet and in a direction which is perpendicular to the surface of the at least one active layer, and wherein said thickness D is greater than or equal to 0.5×W.