Optical switch pathway configuration using control signals

• US 6,320,993 B1
• Filed: 09/16/1999
• Issued: 11/20/2001
• Est. Priority Date: 06/05/1998
• Status: Expired due to Fees

• Current Assignee: Rembrandt Communications LP (Rembrandt IP Management, LLC)
• Original Assignee: Astarte Fiber Networks, Inc. (DZS, Inc.)
• Inventors: Laor, Herzel
• Primary Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US09/397,219
• Time in Patent Office: 796 Days
• Field of Search: 385/16, 385/17, 385/18, 385/19, 385/15, 385/20, 385/23, 385/25, 385/47, 385/52, 385/73, 385/74, 385/92, 385/93, 359/153-156, 250/227.14, 250/227.19, 250/227.24
• US Class Current: 385/16
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• CPC Class Codes: G02B 6/3588 of the processed beams, i.e. controlling during switching of orientation, alignment, or beam propagation properties such as intensity, size or shape
• CPC Class Codes: G02B 6/359 of the position of the moving element itself during switching, i.e. without monitoring the switched beams
• CPC Class Codes: G02B 6/3803 Adjustment or alignment devices for alignment prior to splicing
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/4225 by a direct measurement of the degree of coupling, e.g. the amount of light power coupled to the fibre or the opto-electronic element
• CPC Class Codes: H04Q 11/0003 Details
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0041 Optical control
• CPC Class Codes: H04Q 2011/0043 Fault tolerance
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget
• CPC Class Codes: H04Q 2011/0073 Provisions for forwarding or routing, e.g. lookup tables
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring

Abstract

Control signal systems for use in configuring an optical switch such that a communication signal transmittable from a first fiber end may be transmitted along a desired pathway between the first fiber end and a second fiber end are disclosed. The systems include transmitting a control signal, either on-path or, if the switch is mirror based, off-path with a communication signal pathway over which the communication signal is transmittable in the optical switch. The transmitted control signal is received by a control signal detector that is maintained in a known spatial relation relative to the desired pathway. A feedback signal relating to the spatial relationship between the communication signal pathway and the desired pathway is output by the detector. The feedback signal may be utilized in configuring the optical switch in order to make the communication signal pathway coincident with the desired pathway and thereby achieve transmission of the communication signal over the desired pathway.

Claims

1. A method for use in configuring an optical switch such that a communication signal transmittable from a first fiber end may be transmitted along a desired pathway between the first fiber end and a second fiber end, said method comprising:

transmitting a control signal such that it travels on at least a portion of a communication signal pathway over which the communication signal is transmittable in the optical switch;

receiving the control signal with a control signal detector that is maintained in a known spatial relation relative to the desired pathway; and

outputting a feedback signal from the detector relating to the spatial relationship between the communication signal pathway and the desired pathway, the feedback signal being utilizable in configuring the switch to make the communication signal pathway coincident with the desired pathway.

2. The method of claim 1 wherein said transmitting step includes:

generating the control signal using a control signal transmitter; and

directing the control signal onto the communication signal pathway using a first optical element enabled for receiving the communication signal from the first fiber end on a first entrance pathway and the control signal from the control signal transmitter on a second entrance pathway different than the first entrance pathway and transmitting both the control and communication signal on the communication signal pathway.

3. The method of claim 2 wherein the control signal is generated using a radiation emitting device.

4. The method of claim 2 wherein the communication signal has a first wavelength and the control signal has a second wavelength different than the first wavelength and the first optical element transmits both the control and communication signals on the communication signal pathway by means of wavelength dependent mirror.

5. The method of claim 1 wherein said receiving step includes:

separating the control signal from the communication signal using a second optical element enabled for receiving both the communication and control signals on the communication signal pathway and transmitting the communication signal towards the second fiber end on a first exit pathway and the control signal towards the detector on a second exit pathway different from the first exit pathway.

6. The method of claim 5 wherein the communication signal has a first wavelength and the control signal has a second wavelength different than the first wavelength and the second optical element separates the control signal from the communication signal by means of wavelength dependent mirror.

7. The method of claim 1 wherein in said step of receiving, the control signal is received using a detector which permits substantial transmission of the communication signal therethrough.

8. The method of claim 7 wherein the communication signal has a first wavelength and the control signal has a second wavelength different than the first wavelength and the detector permits substantial transmission of the communication signal therethrough on a wavelength dependent basis.

9. The method of claim 1 wherein the optical switch interfaces the first and second fiber ends by means of positionable mirrors, the feedback signal being utilizable in positioning at least one of the mirrors in order to configure the switch to make the communication signal pathway coincident with the desired pathway.

10. The method of claim 1 wherein the optical switch interfaces the first and second fiber ends by pointing the fiber ends at one another, the feedback signal being utilizable in pointing the first and second fiber ends at one another in order to configure the switch to make the communication signal pathway coincident with the desired pathway.

11. A method for use in configuring a mirror based optical switch having a plurality of positionable mirrors such that a communication signal transmittable from a first fiber end may be transmitted along a desired pathway between the first fiber end and a second fiber end, said method comprising:

transmitting a control signal over a control signal pathway in the optical switch, the control signal pathway being separate from a communication signal pathway over which the communication signal is transmittable in the optical switch and having a known spatial relation relative to the communication signal pathway;

receiving the control signal with a control signal detector that is maintained in a known spatial relation relative to the desired pathway; and

outputting a feedback signal from the detector relating to the spatial relationship between the communication signal pathway and the desired pathway, the feedback signal being utilizable in positioning at least one mirror of the mirror-based optical switch in order to make the communication signal pathway coincident with the desired pathway.

12. The method of claim 11 wherein in said step of transmitting, the control signal pathway is substantially parallel with the communication signal pathway.

13. The method of claim 11 wherein said transmitting step includes:

generating the control signal using a control signal transmitter; and

directing the control signal onto the control signal pathway using a first optical element, the first optical element being enabled for receiving the communication signal from the first fiber end on a first entrance pathway and the control signal from the control signal transmitter on a second entrance pathway different than the first entrance pathway and transmitting the communication and control signals on the communication and control signal pathways, respectively, to the same mirror of the optical switch.

14. The method of claim 13 wherein the control signal is generated using a radiation emitting device.

15. The method of claim 13 wherein the communication signal has a first wavelength and the control signal has a second wavelength different than the first wavelength and the first optical element transmits the communication signal on the communication signal pathway and the control signal on the control signal pathway by means of a wavelength dependent mirror.

16. The method of claim 11 wherein said receiving step includes:

directing the communication signal towards the second fiber end and the control signal towards the control signal detector using a second optical element, the second optical element being enabled for receiving the communication signal on the communication signal pathway and the control signal on the control signal pathway from the same mirror of the optical switch and transmitting the communication signal towards the second fiber end on a first exit pathway and the control signal towards the detector on a second exit pathway different from the first exit pathway.

17. The method of claim 16 wherein the communication signal has a first wavelength and the control signal has a second wavelength different than the first wavelength and the second optical element transmits the communication signal on the first exit pathway and the control signal on the second exit pathway by means of wavelength dependent mirror.