Optical phased array radiator

Abstract

An optical phased array (OPA) radiator includes a plurality of unit radiators configured to serve as optical waveguides, each of the unit radiators being made of a silicon material and each having a predetermined length, where the unit radiators are disposed in parallel; a cladding portion configured to cover the plurality of unit radiators; and a plurality of electrodes arranged in parallel with the plurality of unit radiators on the cladding portion, where the plurality of electrodes are arranged so as not to overlap the plurality of unit radiators in a vertical direction. A beam radiated through the unit radiators using a phased array can be efficiently vertically steered.

What is claimed is: 
     
         1 . An optical phased array (OPA) radiator, comprising:
 a plurality of unit radiators configured to serve as optical waveguides, each of the unit radiators being made of a silicon material and each having a predetermined length, wherein the unit radiators are disposed in parallel;   a cladding portion configured to cover the plurality of unit radiators; and   a plurality of electrodes arranged in parallel with the plurality of unit radiators on the cladding portion,   wherein the plurality of electrodes are arranged so as not to overlap the plurality of unit radiators in a vertical direction.   
     
     
         2 . The OPA radiator of  claim 1 , wherein the plurality of electrodes are arranged between the plurality of unit radiators in the vertical direction. 
     
     
         3 . The OPA radiator of  claim 2 , further comprising:
 doping regions formed in a base portion below the plurality of unit radiators to correspond to in number to the plurality of electrodes, respectively; and   conductive lines configured to connect the plurality of electrodes to a plurality of doping regions.   
     
     
         4 . The OPA radiator of  claim 3 , wherein the plurality of doping regions are arranged so as not to overlap the plurality of unit radiators in the vertical direction. 
     
     
         5 . The OPA radiator of  claim 1 , wherein the cladding portion includes a silica cladding having a refractive index that is lower than a refractive index of the unit radiator. 
     
     
         6 . The OPA radiator of  claim 1 , wherein the plurality of unit radiators have a same interval, and an irregular structure is formed in each of the unit radiators at the same interval in a lengthwise direction. 
     
     
         7 . An optical phased array (OPA) radiator, comprising:
 a plurality of unit radiators configured to serve as optical waveguides, each of the unit radiators being made of a silicon material and each having a predetermined length, wherein the unit radiators are disposed in parallel;   a cladding portion configured to cover the plurality of unit radiators;   first electrodes disposed to be spaced apart from each other on one side of an upper surface of the cladding portion in a widthwise direction of the cladding portion; and   second electrodes disposed to be spaced apart from each other and to be opposite to the first electrodes on the other side of the upper surface of the cladding portion in the widthwise direction of the cladding portion.   
     
     
         8 . The OPA radiator of  claim 7 , further comprising:
 a plurality of doping regions formed in a base portion below the plurality of unit radiators and arranged so as not to overlap the plurality of unit radiators in a vertical direction; and   conductive lines configured to connect the plurality of doping regions to the first electrodes or the second electrodes.   
     
     
         9 . The OPA radiator of  claim 8 , wherein the plurality of doping regions are arranged between the plurality of unit radiators. 
     
     
         10 . The OPA radiator of  claim 9 , wherein the plurality of unit radiators have a same interval, and an irregular structure is formed in each of the unit radiators at the same interval in a lengthwise direction. 
     
     
         11 . The OPA radiator of  claim 10 , wherein:
 each of the plurality of unit radiators is divided into an irregular structure region in which the irregular structure is formed and a non-irregular structure region in which the irregular structure is not formed; and   each of the plurality of unit radiators is tapered such that a width is gradually decreased as being away from the irregular structure region.   
     
     
         12 . The OPA radiator of  claim 11 , wherein:
 each of the plurality of doping regions is divided into a first doping region corresponding to a region which corresponds to the irregular structure region and a second doping region corresponding to a region which corresponds to the non-irregular structure region; and   each of the plurality of doping regions is tapered such that a width is gradually increased as being away from the first doping region.   
     
     
         13 . The OPA radiator of  claim 12 , wherein the conductive line is connected to the second doping region of each of the plurality of doping regions. 
     
     
         14 . The OPA radiator of  claim 7 , wherein the cladding portion includes a silica cladding having a refractive index that is lower than a refractive index of the unit radiator.