Open-axis optical rotary joint

Patent metadata

Field	Value
Publication number	US-11921326-B2
Application number	US-202217714943-A
Country	US
Kind code	B2
Filing date	Apr 6, 2022
Priority date	Apr 6, 2021
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

An optical rotary joint includes a first annular portion and a second annular portion configured to rotate with respect to each other. Optical receivers on a receiver face of the second annular portion receive from optical transmit beam launchers on an emitter face of the first annular portion. The transmit beam launchers transmit optical signals to the optical receivers as the second annular portion rotates with respect to the first annular portion.

First claim

The invention claimed is:

1. An optical rotary joint comprising:
a first annular portion having a receiver face substantially orthogonal to a rotational axis of the rotary joint;
a second annular portion configured to rotate with respect to the first annular portion about the rotational axis, the second annular portion having an emitter face substantially orthogonal to the rotational axis and facing the receiver face;
a plurality of optical receivers on the receiver face facing the emitter face; and
a plurality of optical transmit beam launchers on the emitter face configured to transmit optical signals to the optical receivers as the second annular portion rotates with respect to the first annular portion;
wherein the plurality of optical transmit beam launchers are configured to transmit optical signals at two different wavelengths; and
wherein the plurality of optical receivers further comprise one of two different optical bandpass filters to pass a respective one of the two different wavelengths.

2. The optical rotary joint of claim 1 , wherein the first second annular portion is a rotating portion and comprises a transmit data source, an optical splitter coupled to the transmit data source, and a plurality of optical fibers each coupled to one of the plurality of optical transmit beam launchers at one end and the optical splitter at an opposite end.

3. The optical rotary joint of claim 2 , wherein the transmit data source, the optical splitter and the plurality of optical fibers are all mounted to a supporting structure of the second annular portion.

4. The optical rotary joint of claim 2 , wherein
the optical splitter comprises an optical device that splits the optical signal from the transmit data source into essentially identical replicas for each of the plurality of optical fibers,
the plurality of optical fibers are of nominally equal length, and
the transmit beam launchers comprises a collimator coupled to the respective optical fiber, wherein the collimator is directed to the receiver face.

5. The optical rotary joint of claim 1 , wherein the optical receivers comprise a photodetector and a lens configured to direct a received optical signal to the photodetector and wherein the lens is configured to provide no more than a predetermined time delay variation in optical path length for axial and paraxial optical signals.

6. The optical rotary joint of claim 5 , wherein the predetermined time delay variation is less than one picosecond.

7. The optical rotary joint of claim 5 , wherein the lens consists of a single aspheric element.

8. The optical rotary joint of claim 1 , further comprising a transmit data source for the optical signals at two different wavelengths, an optical splitter coupled to the transmit data source, and a plurality of optical fibers each coupled to one of the plurality of optical transmit beam launchers at one end and the optical splitter at an opposite end.

9. The optical rotary joint of claim 1 , wherein the plurality of optical transmit beam launchers are positioned equiangularly spaced around the emitter face.

10. The optical rotary joint of claim 9 , wherein the optical receivers are positioned on the receiver face with an angular separation of at least 3/2 times the angular separation of the optical transmit beam launchers.

11. The optical rotary joint of claim 1 , wherein the optical receivers convert respective received optical signals to respective electrical signals, the optical rotary joint further comprising a combiner coupled to the optical receivers to receive the electrical signals and combine them to form a single received electrical signal.

12. The optical rotary joint of claim 1 , wherein the transmit beam launchers and the optical receiver are positioned on the emitter face and the receiver face, respectively, so that at least one of the plurality of optical receivers is always receiving an optical signal from at least one of the plurality of transmit beam launchers while the second annular portion rotates with respect to the first annular portion.

13. The optical rotary joint of claim 1 , wherein the transmit beam launchers and the optical receiver are positioned on the emitter face and the receiver face, respectively, so that no optical receivers is receiving an optical signal from two different transmit beam launchers at the same time while the second annular portion rotates with respect to the first annular portion.

14. The optical rotary joint of claim 1 , wherein the transmit beam launchers and the optical receiver are positioned on the emitter face and the receiver face, respectively, so that two different optical receivers receive a same optical signal from two different transmit beam launchers respectively at the same time while the second annular portion rotates with respect to the first annular portion.

15. The optical rotary joint of claim 1 , wherein the transmit beam launchers are positioned over only a portion of the emitter face such that no optical receiver is receiving an optical signal during a portion of the rotation of the second annular portion with respect to the first annular portion and wherein the transmit data source provides transmit data bursts only during the time that the optical signal will be received by an optical receiver.

16. An optical data transmission interface in a rotary joint having a rotational axis comprising:
a first portion of the rotary joint;
a plurality of transmit beam launchers positioned on the first portion and configured to transmit optical beams parallel to the rotation axis;
a second portion of the rotary joint; and
a plurality of optical receivers positioned on the second portion and configured to receive the optical beams from the transmit beam launchers;
wherein the plurality of transmit beam launchers are configured to transmit optical signals at two different wavelengths; and
wherein the plurality of optical receivers further comprise one of two different optical bandpass filters to pass a respective one of the two different wavelengths.

17. The optical data transmission interface of claim 16 , wherein the first portion and the second portion rotate with respect to each other.

18. The optical data transmission interface of claim 16 , wherein the plurality of transmit beam launchers transmit the same optical beam and wherein the optical receivers are positioned to receive the optical beam as the first portion and the second portion rotate with respect to each other.

19. An optical rotary joint comprising:
a first annular portion having a first face substantially orthogonal to a rotational axis of the rotary joint;
a second annular portion configured to rotate with respect to the first annular portion about the rotational axis, the second annular portion having a second face substantially orthogonal to the rotational axis and facing the first face;
a plurality of optical receivers on the first face facing the second face;
a plurality of optical receivers on the second face facing the first face;
a plurality of optical transmit beam launchers on the first face configured to transmit optical signals to the optical receivers on the second face as the second annular portion rotates with respect to the first annular portion; and
a plurality of optical transmit beam launchers on the second face configured to transmit optical signals to the optical receivers on the first face as the second annular portion rotates with respect to the first annular portion;
wherein the plurality of optical transmit beam launchers are confi

Assignees

• Sanmina Corp

Inventors

• Dugan John Michael
• Pastor Curtis
• Alt Mark

Classifications

• G02B6/3604 Primary

  Rotary joints allowing relative rotational movement between opposing fibre or fibre bundle ends · CPC title

• G02B6/4206

  Optical features (G02B6/4207, G02B6/421 take precedence) · CPC title