Feedback stabilization of a loss optimized switch

• US 6,456,751 B1
• Filed: 04/13/2000
• Issued: 09/24/2002
• Est. Priority Date: 04/13/2000
• Status: Expired due to Term

• Current Assignee: Calient Networks Incorporated
• Original Assignee: Calient Networks Incorporated
• Inventors: Bowers, John Edward, Helkey, Roger Jonathon
• Primary Examiner(s): Ullah, Akim E.
• Application Number:
  US09/548,587
• Time in Patent Office: 894 Days
• Field of Search: 385/16, 385/17, 385/18, 385/22, 385/20, 385/24, 385/30-33, 385/39, 385/52, 385/126, 385/127, 385/42, 385/48, 385/147, 359/153-156, 250/227.14, 250/227.19, 250/227.24
• US Class Current: 385/16
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• 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 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams
• CPC Class Codes: G02B 6/422 Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements G02B6/4233, G02B6/4234 take precedence
• 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

Abstract

A system is provided to obtain loss optimized output optical power by way of feedback control and stabilization in an optical signal switching or routing system. The optical signal switching or routing system includes at least two input optical fibers and at least two output optical fibers, a controllable mechanism for directing an optical beam from one of the input optical fibers to one of the output optical fibers, and a mechanism for measuring the optical power applied to output optical fiber. The measuring mechanism provides a measure of the output optical power through a signal processing apparatus to a control apparatus. Possible other inputs to the signal processing apparatus include the input optical power, test optical power, etc. The inputs to the signal processing apparatus are compared and the signal processing apparatus outputs a signal to the control apparatus to provide optimized output power.

Claims

1. An optical system, comprising:

first and second input optical fibers for producing first and second optical beams, respectively;

first and second output optical fibers for receiving either the first or second optical beams;

a control apparatus;

a beam steering apparatus, responsive to the control apparatus, for independently steering the first and second optical beams to and towards the first and second output optical fibers;

first and second output optical power measuring apparatus for measuring the optical power of signals received by the first and second output optical fibers, respectively;

first and second reference optical power sources for providing first and second reference optical power values, respectively;

a signal processing apparatus, communicatively coupled to the first and second reference optical power sources, the first and second output optical power measuring apparatus, and the control apparatus, for;

determining, from the reference optical power values and the measure of the optical power of signals received by said first and second output optical fibers, first and second optimal beam paths which optimize the optical power of signals received by said first and second output optical fibers; and

producing an output control signal which may be employed by the control apparatus for the purpose of controlling the beam steering apparatus to achieve the first and second optimal beam paths.

2. The optical system of claim 1, wherein the first and second reference optical power sources are first and second optical power measuring apparatus, respectively, and the first and second reference optical power values are the input optical power of the first and second input optical fibers, respectively.

3. The optical system of claim 1, wherein the signal processing apparatus includes a ratio circuit, and the output control signal is determined so as to maintain a maximum ratio of the output optical power to the reference optical power.

4. The optical system of claim 1, wherein the ratio is greater than one-half.

5. The optical system of claim 1, wherein the output control signal is determined so as to maintain the optical power received by the first and second optical fibers approximately equal.

6. The optical system of claim 1, wherein the output control signal is determined such that the optical power received by the first and second optical fibers are maintain so as not to exceed a preset value.

7. In a system of the type including at least first and second input optical fibers, first and second output optical fibers, a beam steering apparatus, responsive to a control apparatus, for independently steering optical beams produced by the first and second optical fibers to and towards the first and second output optical fibers, an improvement comprising:

first and second input optical power measuring apparatus for measuring the optical power of signals carried by the first and second input optical fibers, respectively;

first and second output optical power measuring apparatus for measuring the optical power of signals carried by the first and second output optical fibers, respectively;

a signal processing apparatus, communicatively coupled to the first and second input optical power measuring apparatus, the first and second output optical power measuring apparatus, and the control apparatus, for;

determining, from the measure of the optical power of signals carried by the first and second input optical fibers and the measure of the optical power of signals carried by said first and second output optical fibers, first and second optimal beam paths which optimize the optical power of signals carried by said first and second output optical fibers; and

producing an output signal which may be employed by the control apparatus for the purpose of controlling the beam steering apparatus to achieve the first and second optimal beam paths.

8. In the system of claim 7, the improvement further comprising the signal processing apparatus determining the optimal beam paths to correspond to minimized loss between the optical power of signals carried by the first and second input optical fibers and the optical power of signals carried by the first and second output optical fibers.

9. In the system of claim 7, the improvement further comprising the signal processing apparatus determining the optimal beam paths to correspond to a balanced loss between the optical power of signals carried by the first and second output optical fibers.

10. The improvement of claim 7, wherein the first and second input optical power measuring apparatus are communicatively coupled to the first and second input optical fibers, respectively, for measuring the optical power of signals carried by the first and second input optical fibers.

11. The improvement of claim 7, wherein the first and second output optical power measuring apparatus are communicatively coupled to the first and second output optical fibers, respectively, for measuring the optical power of signals carried by the first and second input optical fibers.