Dispersive optical phased array for two-dimensional scanning

Patent metadata

Field	Value
Publication number	US-11249371-B2
Application number	US-202016986539-A
Country	US
Kind code	B2
Filing date	Aug 6, 2020
Priority date	Aug 13, 2019
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A dispersive optical phased array for two-dimensional scanning is disclosed herein. The array comprises antenna blocks positioned adjacent one another. The antenna blocks comprise a plurality of antennas positioned adjacent one another and a plurality of delay lines to couple a coherent source signal to each of the antennas within the block, each delay line having an optical path length. Each of the antenna blocks acts as a dispersive phased array. The antenna blocks are arranged such that the blocks form a larger phased array where the antennas between the blocks are in phase for a discrete set of wavelengths. All antennas over the dispersive phased array can experience the same phase difference such that the beams of the individual antenna blocks align with one of the diffraction orders of the array of blocks.

First claim

What is claimed is:

1. A dispersive optical phased array for two-dimensional scanning, the dispersive optical phased array comprising:
a coherent light source configured to generate coherent light having a time-varying carrier wavelength that varies within a predefined carrier wavelength interval;
a splitter configured to receive the coherent light from the coherent light source;
a first antenna block configured to receive the coherent light from the splitter, the first antenna block comprising a first antenna, a second antenna, and a first delay line, wherein the first antenna and the second antenna are aligned along a line and the first delay line couples the first antenna to the second antenna with a first phase delay that is dependent on the time-varying carrier wavelength; and
a second antenna block configured to receive the coherent light from the splitter, the second antenna block comprising a third antenna, a fourth antenna, and a second delay line, wherein the third antenna and the fourth antenna are also aligned along the line and the second delay line couples the third antenna to the fourth antenna with a second phase delay that is dependent on the time-varying carrier wavelength,
wherein there exists at least one wavelength of the time-varying carrier wavelength within the predefined carrier wavelength interval at which the first antenna, the second antenna, the third antenna, and the fourth antenna are substantially in phase with one another.

2. The dispersive optical phased array according to claim 1 , wherein a third phase delay between the second antenna and the third antenna is substantially equal to the first phase delay between the first antenna and the second antenna for the at least one wavelength.

3. The dispersive optical phased array according to claim 1 , wherein the first antenna block comprises a first plurality of antennas that comprise the first antenna, the second antenna, and a fifth antenna that has a largest phase delay of any antenna of the first plurality of antennas with respect to the first antenna, wherein the second antenna block comprises a second plurality of antennas that comprise the third antenna and the fourth antenna, and wherein a third phase delay between the fifth antenna and the third antenna is substantially equal to the first phase delay between the first antenna and the second antenna for the at least one wavelength.

4. The dispersive optical phased array according to claim 1 , wherein the splitter is configured to provide the coherent light to the first antenna block and the second antenna block at the same phase for substantially all carrier wavelengths within the predefined carrier wavelength interval.

5. The dispersive optical phased array according to claim 1 , further comprising a phase shifter configured to eliminate phase delay of the coherent light between the first antenna block and the second antenna block.

6. The dispersive optical phased array according to claim 1 , further comprising a third antenna block, a fourth antenna block, and a phase shifter configured to phase shift the coherent light provided to the third antenna block and the fourth antenna block with respect to the first antenna block and the second antenna block.

7. The dispersive optical phased array according to claim 1 , wherein the first antenna block and the second antenna block have the same footprint area.

8. The dispersive optical phased array according to claim 1 , wherein the first antenna block has the same number of antennas as the second antenna block.

9. The dispersive optical phased array according to claim 1 , wherein the coherent light source comprises a wavelength tunable laser.

10. The dispersive optical phased array according to claim 1 , wherein the splitter comprises a star coupler.

11. The dispersive optical phased array according to claim 10 , wherein the star coupler is set up in a Rowland configuration.

12. The dispersive optical phased array according to claim 1 , wherein the splitter comprises a star coupler having output waveguides and inputs, wherein the inputs are distributed between the −0.5 and +0.5 diffraction order of the output waveguides such that a phase difference of the coherent light arriving at adjacent antennas is substantially different for each of the inputs.

13. The dispersive optical phased array according to claim 1 , further comprising a third antenna block, wherein the first antenna block, the second antenna block, and the third antenna block are organized in a snake pattern.

14. The dispersive optical phased array according to claim 1 , further comprising a third antenna block, wherein the first antenna block, the second antenna block, and the third antenna block are organized in an imbalanced tree.

15. The dispersive optical phased array according to claim 1 , further comprising a third antenna block, wherein the first antenna block, the second antenna block, and the third antenna block are non-uniformly positioned along the line.

16. The dispersive optical phased array according to claim 1 , further comprising a third antenna block, wherein a spacing between the first antenna block, the second antenna block, and the third antenna block is non-uniform.

17. The dispersive optical phased array according to claim 1 , wherein power is distributed over the first antenna block and the second antenna block in a normal distribution.

18. The dispersive optical phased array according to claim 1 , wherein power is distributed over the first antenna, the second antenna, the third antenna, and the fourth antenna in a normal distribution.

19. The dispersive optical phased array according to claim 1 , wherein an optical path length difference between the first antenna and the second antenna is constant such that the first phase delay is given by k*2πΔL/λ(t).

20. The dispersive optical phased array according to claim 1 , the first antenna block further comprising a fifth antenna, wherein the first antenna, the second antenna, and the fifth antenna are periodically positioned.

Assignees

• Imec Vzw
• Univ Gent

Inventors

• Bogaerts Wim

Classifications

• G01S7/4817 Primary

  relating to scanning · CPC title

• G02B26/10

  Scanning systems · CPC title

• G02B27/0087

  Phased arrays · CPC title

• G02F1/2955 Primary

  by controlled diffraction or phased-array beam steering (controlled diffraction for optical waveguide switching G02F1/313) · CPC title

• G01S17/931

  of land vehicles · CPC title