Acousto-optic system having phase-shifting reflector

Patent metadata

Field	Value
Publication number	US-11705686-B2
Application number	US-201816636605-A
Country	US
Kind code	B2
Filing date	Sep 20, 2018
Priority date	Sep 22, 2017
Publication date	Jul 18, 2023
Grant date	Jul 18, 2023

Abstract

A beam positioner can be broadly characterized as including a first acousto-optic (AO) deflector (AOD) operative to diffract an incident beam of linearly polarized laser light, wherein the first AOD has a first diffraction axis and wherein the first AOD is oriented such that the first diffraction axis has a predetermined spatial relationship with the plane of polarization of the linearly polarized laser light. The beam positioner can include at least one phase-shifting reflector arranged within a beam path along which light is propagatable from the first AOD. The at least one phase-shifting reflector can be configured and oriented to rotate the plane of polarization of light diffracted by the first AOD.

First claim

What is claimed is:

1. A beam positioner for deflecting a beam path, along which a diffracted beam of linearly polarized laser light is propagatable, within a two-dimensional scan field, the beam positioner comprising:
a first acousto-optic (AO) deflector (AOD) operative to diffract the laser light so as to deflect the beam path within a first one-dimensional scan field extending along a first axis of the two-dimensional scan field;
a second AOD operative to diffract the laser light so as to deflect the beam path within a second one-dimensional scan field extending along a second axis of the two-dimensional scan field; and
at least one phase-shifting reflector arranged between the first AOD and the second AOD and within the beam path along which the beam of laser light is propagatable from the first AOD, wherein the at least one phase-shifting reflector is operative to effect a phase shift between S and P components in the beam of laser light incident thereupon,
wherein the first AOD, the second AOD and the at least one phase-shifting reflector are arranged such that the first one-dimensional scan field is incident upon the at least one phase-shifting reflector, and such that the first one-dimensional scan field is projectable onto the second AOD from the at least one phase-shifting reflector in a manner that the first axis of the first one-dimensional scan field is not parallel to the second axis of the second one-dimensional scan field,
wherein each of the first AOD and the second AOD is configured and operative to deflect the beam path along only one axis of the two-dimensional scan field.

2. The beam positioner of claim 1 , wherein
the at least one phase-shifting reflector is configured and oriented to rotate a plane of polarization of the laser light diffracted by the first AOD such that the plane of polarization of the laser light diffracted by the first AOD, as projected onto the second AOD, is parallel to the second one-dimensional scan field.

3. The beam positioner of claim 1 , wherein
the second AOD has a second diffraction axis, and
the at least one phase-shifting reflector is configured and oriented to rotate a plane of polarization of the laser light diffracted by the first AOD such that the plane of polarization of the laser light diffracted by the first AOD, as projected onto the second AOD, is perpendicular to the second diffraction axis one-dimensional scan field.

4. The beam positioner of claim 1 , wherein the at least one phase-shifting reflector includes a half-wave phase-shifting reflector.

5. The beam positioner of claim 1 , wherein the at least one phase-shifting reflector includes two quarter-wave phase-shifting reflectors.

6. The beam positioner of claim 5 , wherein the two quarter-wave phase-shifting reflectors includes:
a first quarter-wave phase-shifting reflector having a first reflector surface; and a
a second quarter-wave phase-shifting reflector having a second reflector surface,
wherein the first quarter-wave phase-shifting reflector and the second quarter-wave phase-shifting reflector are oriented relative to one another such that a surface normal of the first reflector surface is perpendicular to a surface normal of the second reflector surface.

7. The beam positioner of claim 5 , wherein the two quarter-wave phase-shifting reflectors includes:
a first quarter-wave phase-shifting reflector having a first reflector surface; and a
a second quarter-wave phase-shifting reflector having a second reflector surface,
wherein the first quarter-wave phase-shifting reflector and the second quarter-wave phase-shifting reflector are oriented relative to one another such that a surface normal of the first reflector surface is parallel to a surface normal of the second reflector surface.

8. The beam positioner of claim 1 , further comprising at least one galvanometer mirror arranged within the beam path, wherein the at least one phase-shifting reflector is arranged between the first AOD and the galvanometer mirror.

9. The beam positioner of claim 1 , wherein the orientation of the at least one phase-shifting reflector is fixed relative to the first AOD.

10. The beam positioner of claim 1 , wherein the orientation of the at least one phase-shifting reflector is variable relative to the first AOD.

11. The beam positioner of claim 1 , wherein the first AOD includes an AO cell formed of a material including germanium.

12. The beam positioner of claim 1 , wherein the first AOD includes an AO cell formed of a material including quartz.

13. The beam positioner of claim 1 , wherein the at least one phase-shifting reflector is formed of a material including at least one material selected from the group consisting of silicon and copper.

14. The beam positioner of claim 1 , wherein the first one-dimensional scan field is projectable onto the second AOD in a manner that the first axis of the first one-dimensional scan field is perpendicular to the second axis of the second one-dimensional scan field.

15. The beam positioner of claim 1 , further comprising an optical relay system arranged between the first AOD and the second AOD such that the first one-dimensional scan field is projectable onto the second AOD via the optical relay system.

16. The beam positioner of claim 15 , wherein the at least one phase-shifting reflector is arranged between the first AOD and the optical relay system.

17. The beam positioner of claim 15 , wherein the at least one phase-shifting reflector is arranged between the second AOD and the optical relay system.

18. The beam positioner of claim 15 , wherein the optical relay system includes a pair of lenses and wherein the at least one phase-shifting reflector is arranged between the lenses of the pair of lenses.

Assignees

• Electro Scient Ind Inc

Inventors

• Brookhyser James
• Kleinert Jan
• Richter Jered
• Eaton Kurt

Classifications

• G02F1/33

  Acousto-optical deflection devices {(circuit or control arrangements therefor G02F1/113)} · CPC title

• G02F1/0136 Primary

  for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation (G02F1/0353 takes precedence) · CPC title

• H01S3/1068 Primary

  using an acousto-optical device · CPC title

• G02B6/42

  Coupling light guides with opto-electronic elements · CPC title

• G02B26/06

  for controlling the phase of light (G02B26/08 takes precedence {, measuring optical phase difference G01J9/00}) · CPC title