Patent ID: 6826219
Filing Date: 2004-11-30
Classification: H01S

Abstract:
A semiconductor saturable absorber device for reflecting at least a proportion of electromagnetic radiation of essentially one given optical frequency impinging on said device, comprisinga substrate, a first layered structure comprising a stack of layers placed on said substrate, said stack comprising alternating layers of a first material having a first index of refraction and of a second material having a second index of refraction, said first and said second indices of refraction being different from each other, said stack forming a Bragg reflector for radiation of said optical frequency, a second layered structure placed adjacent to said first layered structure and comprising at least one layer with semiconductor material having a nonlinear optical absorption at said given optical frequency, and a dielectric coating layer placed on an outermost surface of said second layered structure, such that an interface is formed between said second layered structure and said dielectric coating layer, an index of refraction of said dielectric coating layer being lower than said first index of refraction and said second index of refraction, wherein said stack of layers, said second lay red structure and said dielectric coating layer cooperate such that the field intensity of radiation of said given optical frequency is at a maximum at or near said interface between said second layered structure and said dielectric coating layer.