Apparatus and manufacturing method for an integrated multicast switch, for use in reconfigurable optical add-drop networks

• US 9,998,252 B2
• Filed: 09/25/2014
• Issued: 06/12/2018
• Est. Priority Date: 02/21/2014
• Status: Active Grant

• Current Assignee: DiCon Fiber Optics Incorporated
• Original Assignee: DiCon Fiber Optics Incorporated
• Inventors: Lee, Ho-Shang
• Primary Examiner(s): SANDHU, AMRITBIR K
• Application Number:
  US14/497,032
• Publication Number:
  US 20150244492A1
• Time in Patent Office: 1,356 Days
• Field of Search: 398 45- 57, 385 14- 18
• CPC Class Codes: G02B 2006/1215 Splitter
• CPC Class Codes: G02B 6/30 for use between fibre and thin-film device
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3636 the mechanical coupling means being grooves G02B6/3652 takes precedence
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/003 using switches based on microelectro-mechanical systems [MEMS]
• CPC Class Codes: H04Q 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
• CPC Class Codes: H04Q 2011/0047 Broadcast; Multicast

Abstract

In one embodiment, each of the output/input ports of each one of a plurality of optical splitters is connected to one of a plurality of optical switches by means of optical fibers without any fusion splicing in a majority of the optical fibers, and each of the input/output ports of each one of the switches is connected to one of the optical splitters by means of the optical fibers without any fusion splicing in a majority of the optical fibers. Each of the output/input ports of each one of the optical splitters may be directly connected to the ferrule and one of the input/output ports of one of the switches by the optical fibers. The optical splitters may be implemented in at least one planar lightwave circuit (PLC) chip. Optionally, at least one fiber holder defining a plurality of channels therein may be used to hold the optical fibers each of which is aligned with a corresponding output/input port of one of the optical splitters.

Claims

1. A multicast optical switching device comprising:

M optical splitters, each having one first port and N second ports, and thereby designated as an 1×

N optical splitter, M and N being integers greater than 1;

N optical switches, each having a ferrule, M third ports and one fourth port, and thereby designated as a M×

1 optical switch;

a first set of optical fibers, a majority of the optical fibers in the first set directly connecting one of the N second ports of one of the M optical splitters to the ferrule and one of the third ports of one of the N optical switches, wherein the N second ports of each one of the M optical splitters are connected to the N optical switches without any fusion splicing in the majority of the optical fibers in the first set;

a second set of N optical fibers;

the ferrule of each optical switch of the N optical switches housing the M optical fibers in the first set connected to the M third ports of the each optical switch and an optical fiber in the second set connected to the one fourth port of the each optical switch, each of the N optical switches further comprising a lens and a movable micro-electro-mechanical (MEMS) mirror that are aligned with the ferrule of the each optical switch, and

a third set of M optical fibers each connected to the first port of one of the M optical splitters, wherein by controlling a position of the MEMS mirror in each of the N optical switches, radiation from any one of the M optical fibers in the third set is transmitted to a selected one of the optical fibers in the second set in a forward direction, and radiation from any one of the N optical fibers in the second set is transmitted to a selected one of the M optical fibers in the third set in a reverse direction.

2. The device of claim 1, wherein the ferrule of each of the N optical switches is fixed in position relative to the lens of the each optical switch.

3. The device of claim 1, further comprising an anti-reflection coating on an end face of the ferrule of at least one of the N optical switches.

4. The device of claim 1, wherein the M optical splitters are implemented in at least one planar lightwave circuit (PLC) chip, or as thin-film splitters, or Fused Biconical Taper splitters.

5. The device of claim 1, wherein the M optical splitters are commercially-available components, provided with the first set of optical fibers as fiber pigtails of the commercially-available components.

6. A multicast optical switching device comprising:

at least one planar lightwave circuit (PLC) chip that contains M optical splitters, each splitter having one first port and N second ports, and thereby designated as an 1×

N optical splitter, M and N being integers greater than 1;

N optical switches, each having M third ports and one fourth port and thereby designated as a M×

1 optical switch;

at least one fiber holder defining a plurality of channels therein, the at least one fiber holder separated from the PLC chip by a gap; and

each optical fiber of the plurality of optical fibers being held in one of the plurality of channels and aligned with a corresponding second port of one of the M optical splitters, each optical fiber and the corresponding second port defining there between a corresponding optical path, a majority of the plurality of optical fibers connected to the M third ports of the N optical switches;

wherein the N second ports of each one of the M optical splitters are connected to the N optical switches by means of the plurality of optical fibers and through the corresponding optical paths, without any fusion splicing in the majority of the plurality of optical fibers;

the multicast optical switching device comprising M planar lightwave circuit (PLC) chips and M fiber holders, each of the M PLC chips containing one of the M optical splitters, each of the M fiber holders holding the N optical fibers that are connected to a third port of each of the N optical switches and to the N second ports of a corresponding one of the M optical splitters;

each optical switch of the N optical switches further comprising a lens and movable micro-mechanical systems (MEMS) mirror that are aligned with a ferrule containing the M third ports and the fourth port of the each optical switch;

wherein by controlling a position of the movable MEMS mirror in each of the optical switches, radiation from the second port of a selected one of the M optical splitters is transmitted to the third port of any one of the N optical switches in a forward direction, and radiation from the fourth port of a selected one of the N optical switches is transmitted to the first port of any one of the M optical splitters in a reverse direction, through the plurality of optical fibers.

7. The device of claim 6, wherein each channel of the M fiber holders includes a V-groove for holding an optical fiber.

8. The device of claim 6, each of the PLC chips including a waveguide structure comprising a cascaded series of 1×

2 splitter elements.

9. The device of claim 6, wherein each of the M fiber holders is bonded to the corresponding one of the M optical splitters to form a sub-assembly.

10. The device of claim 6, further comprising an anti-reflection coating on an end face of at least one of the M fiber holders and an anti-reflection coating on an end face of the one optical splitter corresponding to the at least one M fiber holder.

11. The device of claim 6, wherein at least some of the second ports of the M optical splitters are spaced apart by a distance in between adjacent second ports, and at least some of the plurality of channels are spaced apart by substantially the distance in between adjacent channels.

12. The device of claim 6, wherein the N optical switches are commercially-available components provided with the plurality of optical fibers as fiber pigtails of the components.

13. The device of claim 6 wherein the ferrule of each of the N optical switches is fixed in position relative to the lens of the each optical switch.

14. A method for making a multicast optical switching device comprising:

providing at least one planar lightwave circuit (PLC) chip that contains M optical splitters, each splitter having one first port and N second ports, and thereby designated as an 1×

N optical splitter, M and N being integers greater than 1;

providing N optical switches, each having M third ports and one fourth port and thereby designated as a M×

1 optical switch, each of the N optical switches previously provided with M optical fibers each fiber of the M optical fibers connected to one of the M third ports of the M×

1 optical switch;

providing at least one fiber holder defining a plurality of channels therein;

causing each of the M optical fibers of the N optical switches to be held in one of the plurality of channels;

aligning each of the M optical fibers held in one of the plurality of channels with a corresponding second port of one of the M optical splitters across a gap between the at least one fiber holder and the one optical splitter, each of the M optical fibers and the corresponding second port aligned with one of the M optical fibers defining there between a corresponding optical path;

wherein the N second ports of each one of the M optical splitters are connected to the N optical switches without any fusion splicing in a majority of the optical fibers; and

providing each of the N optical switches with a corresponding movable micro-electro-mechanical (MEMS) mirror, and controlling a position of the moveable MEMS mirror corresponding to each one of the N optical switches, so that radiation from any one of the M optical splitters is transmitted to a selected one of the N optical switches in a forward direction, and so that radiation from any one of the switches is transmitted to a selected one of the M optical splitters in a reverse direction.

15. The method of claim 14, wherein the at least one planar lightwave circuit (PLC) chip is made by forming waveguide structures on a surface of a substrate to implement the M optical splitters formed by a cascaded series of 1×

2 splitters.

16. The method of claim 14, wherein the at least one fiber holder is made by forming V groove structures on a surface of a substrate to implement the plurality of channels, each of the V groove structures suitable for holding an optical fiber.

17. The method of claim 16, wherein at least some of the second ports of the M optical splitters are spaced apart by a distance in between adjacent-second ports, and at least some of the V groove structures are spaced apart by substantially the distance in between adjacent V groove structures.

18. The method of claim 14, wherein the N optical switches are commercially-available components provided with (M×

N) optical fibers as fiber pigtails of said components, and the aligning aligns the optical fibers of the commercially-available components with corresponding second ports of the M optical splitters.

19. A method for making a multicast optical switching device, the method comprising:

providing M optical splitters, each having one first port and N second ports, designated as an 1×

N optical splitter, M and N being integers greater than 1;

providing N optical switches, each having a ferrule, M third ports and one fourth port, designated as a M×

1 optical switch;

directly connecting one of the N second ports of each one of the M optical splitters to the ferrule and to one of the M third ports of one of the N switches by an optical fiber in a first set of optical fibers, so that each of the N second ports of each one of the M optical splitters is connected to one of the N optical switches by a majority of optical fibers in the first set without any fusion splicing in the majority of the optical fibers in the first set, and each of the M third ports of each one of the switches is connected to one of the M optical splitters without any fusion splicing in the majority of said optical fibers in the first set;

aligning the ferrule of a plurality of ferules of each of the N optical switches with a corresponding lens and a corresponding movable micro-electro-mechanical systems (MEMS) mirror after the second ports of the M optical splitters are connected to the plurality of ferrules of the N optical switches; and

controlling a position of the movable MEMS mirror in each of the N optical switches, so that radiation from any one of M optical fibers in a third set is transmitted to a selected one of N optical fibers in a second set in a forward direction, and so that radiation from any one of the N optical fibers in the second set is transmitted to a selected one of the M optical fibers in the third set in a reverse direction.

20. The method of claim 19, wherein the M optical splitters are commercially-available components, provided with the first set of optical fibers as fiber pigtails of the commercially-available components, and said connecting directly connects said fiber pigtails to the ferrules of the N optical switches.