Integrated planar optical phased array

Patent metadata

Field	Value
Publication number	US-10634845-B2
Application number	US-201514791187-A
Country	US
Kind code	B2
Filing date	Jul 2, 2015
Priority date	Feb 16, 2012
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

An optical phased array includes, in part, a multitude of optical signal emitters and a multitude of optical signal phase/delay elements each associated with and disposed between a different pair of the optical signal emitters. Each optical signal phase/delay element is adapted to cause a phase/delay shift between the optical signals emitted from its associated pair of optical signal emitters. Each optical signal phase/delay element is optically a ring resonator that includes a p-i-n junction. By varying the bias applied to the p-i-n junction, the phase/delay generated by the ring resonator is varied. Furthermore, each optical signal emitter is optionally an optical grating having a multitude of grooves. The groove lengths of the optical gratings are optionally selected so as to increase along the direction of travel of the input optical signal through the optical phase array.

First claim

What is claimed is:

1. An optical phased array comprising:
a first array of N optical signal emitters, said array receiving a first optical signal, each optical signal emitter emitting a portion of the received optical signal into free space, said N being an integer greater than or equal to 2; and
a first array of M optical signal delay elements, each optical signal delay element being associated with and disposed between a different pair of optical signal emitters, each optical signal delay element causing a difference between phases of the optical signals emitted from its associated pair of optical signal emitters, wherein M is an integer greater than or equal to one.

2. The optical phased array of claim 1 wherein the phase difference caused by each of the M optical signal delay elements is variable.

3. The optical phased array of claim 2 wherein the phase differences caused by at least a subset of the M optical signal delay elements are varied so as to change an angle of an output optical signal generated due to interference between one or more of N optical signals emitted by the N optical signal emitters.

4. The optical phased array of claim 1 wherein each of the M optical signal delay elements is a ring resonator.

5. The optical phased array of claim 4 wherein each of the M optical ring resonators is a p-i-n junction causing a phase difference in response to an applied bias.

6. The optical phased array of claim 1 wherein each of the N optical signal emitters is an optical grating comprising a plurality of grooves.

7. The optical phased array of claim 6 wherein groove lengths of the N optical gratings are selected so as to increase along a direction of travel of the first optical signal through the optical phase array.

8. The optical phased array of claim 7 wherein the groove lengths of the N optical gratings are selected so as to achieve a substantially similar intensity for the N emitted optical signals.

9. The optical phased array of claim 1 further comprising:
a second array of K optical signal emitters formed parallel to the first array of the N optical signal emitters, said second array receiving a second optical signal, said K being an integer greater than 2; and
a second array of L optical signal delay elements, each of the L optical signal delay elements being associated with and disposed between a different pair of the K optical signal emitters, each of the L optical signal delay elements causing a difference between phases of the optical signals emitted from its associated pair of optical signal emitters, wherein L is an integer greater than or equal to one.

10. The optical phased array of claim 9 wherein the N optical signals emitted from the first array of N optical signal emitters and the K optical signals emitted from the second array of K optical signal emitters have substantially similar wavelengths.

11. The optical phased array of claim 1 wherein the first array of N optical signal emitters and the first array of M optical signal delay elements are formed in a first semiconductor substrate.

12. The optical phased array of claim 9 wherein the first array of N optical signal emitters, the second array of K optical signal emitters, the first array of the M optical signal delay elements, and the second array of the L optical signal delay elements are formed in a first semiconductor substrate.

13. The optical phased array of claim 9 wherein said first and second optical signals are derived from a same source of optical signal.

14. The optical phased array of claim 9 further comprising:
a third array of P optical signal emitters receiving a third optical signal, said P being an integer greater than 2; and
a third array of Q optical signal delay elements, each of the Q optical signal delay elements being associated with and disposed between a different pair of P optical signal emitters, each of the Q optical signal delay elements causing a difference between phases of the optical signals emitted from its associated pair of optical signal emitters wherein Q is an integer greater than or equal to one.

15. The optical phased array of claim 1 wherein the optical signals emitted by the first array of N optical signal emitters are substantially parallel to a surface of a substrate in which the first array of N optical signal emitters and the first array of M optical signal delay elements are formed.

16. The optical phased array of claim 1 wherein the optical signals emitted by the first array of N optical signal emitters are substantially perpendicular to a surface of a substrate in which the first array of N optical signal emitters and the first array of M optical signal delay elements are formed.

17. A method of generating N optical signals, N being an integer greater than or equal to 2, the method comprising:
forming a first array of N optical signal emitters said array receiving a first optical signal, each optical signal emitter emitting a portion of the received optical signal into free space; said N being an integer greater than or equal to 2; and
forming a first array of M optical signal delay elements, each optical signal delay element being associated with and disposed between a different pair of optical signal emitters, each optical signal delay element causing a difference between phases of the optical signals emitted from its associated pair of optical signal emitters, wherein M is an integer greater than or equal to one.

18. The method of claim 17 further comprising: varying the phase difference caused by each of the M optical signal phase elements.

19. The method of claim 18 further comprising:
varying the phase difference caused by at least a first subset of the M optical signal delay elements so as to change an angle of an output optical signal generated due to interference between one or more of N optical signals emitted by the N optical signal emitters.

20. The method of claim 17 wherein each of the M optical signal delay elements is a ring resonator.

21. The method of claim 20 wherein each of the M optical ring resonators is a p-i-n junction causing a phase difference in response to an applied bias.

22. The method of claim 17 wherein each of the N optical signal emitters is an optical grating comprising a plurality of grooves.

23. The method of claim 22 further comprising:
selecting groove lengths of the N optical gratings in an increasing order along a direction of travel of the first optical signal through the optical phase array.

24. The method of claim 23 further comprising:
selecting the groove lengths of the N optical gratings such that intensities of the N emitted optical signals are substantially similar.

25. The method of claim 17 further comprising:
forming a second array of K optical signal emitters parallel to the first array of the N optical signal emitters, said second array receiving a second optical signal, said K being an integer greater than 2; and
forming a second array of L optical signal delay elements, each of the L optical signal delay elements being associated with and disposed between a different pair of the K optical signal emitters, each of the L optical signal delay elements causing a difference between phases of the optical signals emitted from its associated pair of optical signal emitters, wherein L is an integer greater than or equal to one.

26. The method of claim 25 wherein the N optical signals emitte

Assignees

• California Inst Of Techn

Inventors

• Aflatouni Firooz
• Abiri Behrooz
• Hajimiri Seyed Ali

Classifications

• G02B6/34

  utilising prism or grating {(G02B6/293 takes precedence)} · CPC title

• G02F1/025

  in an optical waveguide structure (G02F1/017, {G02F1/2257} take precedence) · CPC title

• G02B6/124 Primary

  Geodesic lenses or integrated gratings · CPC title

• G02F1/292

  by controlled diffraction or phased-array beam steering (controlled diffraction for optical switching G02F1/31) · CPC title

• G02F2203/15

  involving resonance effects, e.g. resonantly enhanced interaction · CPC title