Electrically pumped semiconductor evanescent laser

Abstract

An apparatus and method electrically pumping a hybrid evanescent laser. For one example, an apparatus includes an optical waveguide disposed in silicon. An active semiconductor material is disposed over the optical waveguide defining an evanescent coupling interface between the optical waveguide and the active semiconductor material such that an optical mode to be guided by the optical waveguide overlaps both the optical waveguide and the active semiconductor material. A current injection path is defined through the active semiconductor material and at least partially overlapping the optical mode such that light is generated in response to electrical pumping of the active semiconductor material in response to current injection along the current injection path at least partially overlapping the optical mode.

1 . An apparatus, comprising:
 an optical waveguide disposed in silicon;   an active semiconductor material disposed over the optical waveguide defining an evanescent coupling interface between the optical waveguide and the active semiconductor material such that an optical mode to be guided by the optical waveguide overlaps both the optical waveguide and the active semiconductor material; and   a current injection path defined through the active semiconductor material and at least partially overlapping the optical mode such that light is generated in response to electrical pumping of the active semiconductor material in response to current injection along the current injection path at least partially overlapping the optical mode.   
     
     
         2 . The apparatus of  claim 1  wherein the active semiconductor material comprises an electrically pumped light emitting layer. 
     
     
         3 . The apparatus of  claim 2  wherein the active semiconductor material comprises multiple quantum well (MQW) regions overlapping the optical mode. 
     
     
         4 . The apparatus of  claim 1  wherein the current injection path is further defined through the evanescent coupling interface and through the silicon. 
     
     
         5 . The apparatus of  claim 1  further comprising current injection confinement regions defined on opposite lateral sides of the active semiconductor material to help confine the current injection through the active semiconductor material to overlap the optical mode. 
     
     
         6 . The apparatus of  claim 5  wherein the current injection confinement regions comprise proton implanted regions of the active semiconductor material. 
     
     
         7 . The apparatus of  claim 5  wherein the current injection confinement regions comprise at least semi-insulating material disposed on the opposite lateral sides of the active semiconductor material. 
     
     
         8 . The apparatus of  claim 1  wherein the optical waveguide is included within an optical cavity of a laser. 
     
     
         9 . The apparatus of  claim 8  wherein the cavity is defined between reflectors disposed in the semiconductor material. 
     
     
         10 . The apparatus of  claim 1  further comprising a ring resonator disposed in the semiconductor material and optically coupled to the optical waveguide. 
     
     
         11 . The apparatus of  claim 1  further comprising at least first and second contacts defined at opposite ends of the current injection path. 
     
     
         12 . The apparatus of  claim 11  wherein the at least first and second contacts are directly coupled to the active semiconductor material 
     
     
         13 . The apparatus of  claim 11  wherein the first contact is directly coupled to the active semiconductor material and the second contact is directly coupled to the silicon. 
     
     
         14 . The apparatus of  claim 1  wherein the optical waveguide is one of a plurality of waveguides over which the active semiconductor material is disposed to form a plurality of lasers. 
     
     
         15 . The apparatus of  claim 1  wherein the evanescent coupling interface includes a bonding interface between the optical waveguide and the active semiconductor material. 
     
     
         16 . A method, comprising:
 guiding an optical mode with an optical waveguide disposed in silicon;   overlapping both the optical waveguide and an active semiconductor material evanescently coupled to the optical waveguide with the optical mode guided through the optical waveguide;   electrically pumping the active semiconductor material to inject current directed through the active semiconductor material and through the optical mode; and   generating light in the active semiconductor material in response to the injected current.   
     
     
         17 . The method of  claim 16  further comprising confining the injected current with confinement regions defined in the active semiconductor material to direct the injected current through the optical mode. 
     
     
         18 . The method of  claim 16  wherein injecting current directed through the active semiconductor material further comprises directing the injected current through an evanescent coupling interface between the active passive semiconductor material and silicon and through the optical mode in the optical waveguide. 
     
     
         19 . The method of  claim 16  further comprising lasing light within an optical cavity including the optical waveguide. 
     
     
         20 . A system, comprising:
 a laser including:
 an optical waveguide disposed in silicon; 
 an active semiconductor material disposed over the optical waveguide defining an evanescent coupling interface between the optical waveguide and the active semiconductor material such that an optical mode to be guided by the optical waveguide overlaps both the optical waveguide and the active semiconductor material; 
 a current injection path defined through the active semiconductor material and at least partially overlapping the optical mode such that light is generated in response to electrical pumping of the active semiconductor material in response to current injection along the current injection path at least partially overlapping the optical mode; 
   an optical receiver optically coupled to receive the light generated by the laser; and   an optical fiber through which the light generated by the laser is directed from the laser to the optical receiver.   
     
     
         21 . The system of  claim 20  further comprising an optical modulator optically coupled to modulate the light generated by the laser. 
     
     
         22 . The system of  claim 20  wherein the active semiconductor material comprises multiple quantum well (MQW) regions overlapping the optical mode. 
     
     
         23 . The system of  claim 20  wherein the current injection path is further defined through the evanescent coupling interface and through the silicon.