Patent ID: 9184558
Filing Date: 2015-11-10
Classification: B82Y,G02B,H01L,H01S

Abstract:
1. An optical semiconductor device, comprising: a first semiconductor layer including a plurality of first grooves and a plurality of ridges formed along a first direction, each of the plurality of first grooves being between the ridges; a plurality of first diffraction grating layers disposed at a spacing from each other along the first direction above the first semiconductor layer, the width of a lower surface of each of the plurality of first diffraction gratings along the first direction being wider than or equal to the width of an upper surface of the first diffraction grating; a second diffraction grating layer disposed along the first direction, the first and second diffraction grating layers being alternately disposed at a spacing from each other, the width of an upper surface of the second diffraction grating layer along the first direction being wider than the width of a lower surface of the second diffraction layer; a diffraction grating including the first and the second diffraction grating layers; a second semiconductor layer disposed between the first and the second diffraction grating layers and under the second diffraction grating layer, the second semiconductor layer having a refractive index different from any of the first and the second diffraction grating layers and being contact with the upper surface of the first diffraction grating layers, wherein the second diffraction grating layer is disposed in second grooves in the second semiconductor layer, the second grooves in the second semiconductor layer being above the first grooves; and a third semiconductor layer disposed over the first and the second diffraction grating layers, the third semiconductor layer having a refractive index different from any of the first and the second diffraction layers, the third semiconductor layer being in contact with the upper surface of the second diffraction grating layers.