Patent ID: 8073034
Filing Date: 2011-12-06
Classification: H01S

Abstract:
1. A mesa vertical-cavity surface-emitting laser (VCSEL) comprising: a distributed Bragg reflector (DBR) layer of semiconductor material, for reflecting light at a lasing wavelength; an active layer of semiconductor material, disposed on a top surface of the DBR layer, for lasing at the lasing wavelength; a first DBR mesa of semiconductor material, disposed on a mesa region of a top surface of the active layer, for reflecting light at the lasing wavelength; a contact annulus of metallic material, disposed on a contact region of the top surface of the first DBR mesa, for passing current to or from the mesa VCSEL, wherein an inner circumference of the contact annulus defines a window region of the top surface of the first DBR mesa; and a second DBR mesa of dielectric material, disposed at least on the window region of the top surface of the first DBR mesa, for reflecting light at the lasing wavelength; wherein the first DBR mesa has a first reflectance at the lasing wavelength that is insufficient to sustain lasing in the active layer; wherein the first DBR mesa and the second DBR mesa together have a total reflectance at the lasing wavelength that is sufficient to sustain lasing in the active layer under the window region; wherein the first DBR mesa includes a capping layer, disposed at a top surface of the first DBR mesa, for facilitating ohmic contacting with the contact annulus, and a first spacer layer, for mitigating optical absorption by the capping layer at the lasing wavelength, wherein the capping layer is disposed on a top surface of the first spacer layer; and wherein the second DBR mesa includes a second spacer layer, disposed at a bottom surface of the second DBR mesa on a top surface of the capping layer, for mitigating optical absorption by the capping layer at the lasing wavelength.