Multicast switch array and beam steering device using same

1 . A beam steering device comprising:

a first waveguide through which light is input;

a switch array comprising a plurality of switches which arranged in a line on a plane of a substrate along the first waveguide and respectively connected to the first waveguide;

a plurality of grating couplers which arranged separately from the plurality of switches and respectively connected to the plurality of switches; and

a lens for receiving the light emitted from the plurality of grating couplers,

wherein the plurality of grating couplers are arranged in a two-dimensional array on the plane of the substrate, and the line of the plurality of switches is disposed outside of an area where the two-dimensional array of the plurality of grating couplers is arranged,

wherein each of the individual switches constituting the plurality of switches provides a second waveguide for transmitting the light to a corresponding single grating coupler connected to the individual switch by switching on, such that the light is branched directly from the first waveguide to the corresponding single grating coupler via only one switch,

wherein each of the plurality of grating couplers provides one fixed beam emission angle determined by a position of each grating coupler relative to the lens, and

wherein the switch array is configured to perform a multicast operation by simultaneously switching on two or more switches to distribute the input light from the first waveguide into two or more second waveguides with a controllable power splitting ratio so that the light passing through the lens forms a predetermined multi-beam pattern corresponding to the two or more switched-on switches.

2 . The beam steering device of claim 1 , wherein each of the plurality of switches comprises a directional coupler configured to distribute at least a part of input light transmitted along the first waveguide to the second waveguide.

3 . The beam steering device of claim 2 , wherein the directional coupler comprises a coupler unit configured to form at least a part of the second waveguide.

4 . The beam steering device of claim 3 , wherein the directional coupler is configured to control an optical power splitting ratio of the input light, based on a distance between the at least a part of the second waveguide and the first waveguide.

5 . The beam steering device of claim 3 , wherein the directional coupler is configured to move the coupler unit to adjust a distance between the at least a part of the second waveguide and the first waveguide.

6 . The beam steering device of claim 5 , wherein the coupler unit is configured to be movable such that the distance between the at least a part of the second waveguide and the first waveguide becomes a predetermined distance value while the at least a part of the second waveguide and the first waveguide remain parallel to each other.

7 . The beam steering device of claim 5 , wherein the directional coupler is configured to move the coupler unit by a micro electro mechanical systems (MEMS)-based actuator.

8 . A switch array for beam steering, the switch array comprising:

a plurality of switches arranged in a line on a plane of a substrate along a first waveguide through which light is input, and connected to the first waveguide,

wherein the plurality of switches are connected to a plurality of grating couplers, each of the plurality of grating couplers provides one beam emission angle,

wherein each of the plurality of switches is configured to provide a second waveguide that branches directly from the first waveguide to a corresponding grating coupler via only one switching stage, wherein each of the plurality of switches comprises a directional coupler configured to control an optical power splitting ratio of the input light from the first waveguide to the second waveguide, and

the switch array is configured to perform a multicast operation by simultaneously switching on two or more switches to distribute the input light into two or more second waveguides with controllable power splitting ratios required for forming a predetermined multi-beam pattern among the plurality of switches.

9 . The switch array of claim 8 , wherein each of the plurality of switches comprises a directional coupler configured to distribute at least a part of input light transmitted along the first waveguide to the second waveguide.

10 . The switch array of claim 9 , wherein the directional coupler is configured to control an optical power splitting ratio of the input light, based on a distance between at least a part of the second waveguide and the first waveguide.

11 . The switch array of claim 9 , wherein the directional coupler is configured to move a coupler unit to adjust a distance between at least a part of the second waveguide and the first waveguide.

12 . The switch array of claim 11 , wherein the coupler unit is configured to be movable such that the distance between the at least a part of the second waveguide and the first waveguide becomes a predetermined distance value while the at least a part of the second waveguide and the first waveguide remain parallel to each other.