Optical energy transmission system utilizing precise phase and amplitude control

• US 6,708,003 B1
• Filed: 12/16/1999
• Issued: 03/16/2004
• Est. Priority Date: 12/16/1999
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Wickham, Michael G., Upton, Eric L.
• Primary Examiner(s): Pascal, Leslie
• Assistant Examiner(s): SINGH, DALZID E
• Application Number:
  US09/466,370
• Time in Patent Office: 1,552 Days
• Field of Search: 359/157, 359/193, 359/140, 359/123, 359/124, 359/126-129, 359/130-131, 359/132, 359/138, 359/153, 359/161, 359/181-187, 398/53, 398/77, 398/79, 398/82, 398/86-88, 398/93, 398/150, 398/161, 398/162, 398/177, 398/183, 398/190, 398/198, 398/209, 398/212, 398/213, 398/102, 385/14, 385/27, 385/39
• US Class Current: 398/102
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/1307 Stabilisation of the phase
• CPC Class Codes: H01S 3/2383 Parallel arrangements
• CPC Class Codes: H04B 10/1121 One-way transmission
• CPC Class Codes: H04J 14/007 Orthogonal Optical Code Multiplex

Abstract

An optical transmission system includes an optical source for providing an input optical signal to an optical array having a plurality of delay lines, and by utilizing orthogonal code modulation for active optical wave component control, the optical signal split among the plurality of delay lines is phase and amplitude modulated for efficient transmission to a destination point.

Claims

1. An optical transmission system, comprising:

a source for transmitting an input optical signal;

an optical array having a primary input for receiving said optical signal;

a plurality of delay lines, each said delay line having an input, an output, and a predetermined optical path length;

an optical splitter coupled to said primary input, for splitting said input optical signal into a plurality of delay line signals, each of said delay line signals being input to one corresponding delay line input and each said delay carries its respective delay line signal to a destination point located at said delay line outputs;

means for producing a plurality of control signals, utilizing orthogonal code modulation, to control the modulation of an optical wave component of each said delay line signal; and

means for modulating each said delay line optical wave component according to said corresponding control signal;

and wherein said means for producing a plurality of control signals comprises a processor for receiving electrical signals derived from output optical signals sampled at said delay line outputs, and for generating therefrom each one of said control signals by independently determining an optimal modulation value of said optical wave component of each of said corresponding delay line signals.

2. An optical transmission system as recited in claim 1, wherein said delay line optical wave component is an optical phase.

3. An optical transmission system as recited in claim 1, wherein said delay line optical wave component is an optical amplitude.

4. An optical transmission system as recited in claim 1, wherein said means for modulating each said delay line optical wave component comprises:

a plurality of phase modulators, wherein each said phase modulator is a waveguide segment located in a section of one corresponding delay line and having means for adjusting said delay line optical path length according to said corresponding control signal.

5. An optical transmission system as recited in claim 4, wherein said waveguide segment is formed of a material having a variable index of refraction, such that when an electric signal is applied to said waveguide segment said variable index of refraction is correspondingly modified.

6. An optical transmission system as recited in claim 5, wherein said waveguide segment material is a photonics semiconductor material.

7. An optical transmission system as recited in claim 5, wherein said waveguide segment material is selected from the group consisting of lithium niobate and gallium aluminum arsenide.

8. An optical transmission system as recited in claim 4, wherein each said modulator is a piezoelectric device.

9. An optical transmission system as recited in claim 4, wherein said means for modulating each said delay line optical wave component further comprises:

a plurality of amplitude modulators, each said amplitude modulator disposed in a section of one corresponding delay line and having means for adjusting an amplitude of each said delay line signal according to said corresponding control signal.

10. An optical transmission system as recited in claim 1, further comprising:

a plurality of microlenses, each one of said microlenses providing optical focusing of one corresponding said delay line signal output; and

a plurality of optical amplifiers, each one of said amplifiers providing optical amplification of one corresponding said delay line signal.

11. An optical transmission system, comprising:

a source for transmitting an input optical signal;

an optical array having a primary input for receiving said optical signal;

a plurality of delay lines, each said delay line having an input, an output, and a predetermined optical path length;

an optical splitter coupled to said primary input, for splitting said input optical signal into a plurality of delay line signals, each of said delay line signals being input to one corresponding delay line input and each said delay carries its respective delay line signal to a destination point located at said delay line outputs;

means for producing a plurality of control signals, utilizing orthogonal code modulation, to control the modulation of an optical wave component of each said delay line signal; and

means for modulating each said delay line optical wave component according to said corresponding control signal;

and wherein said means for producing said plurality of control signals comprises;

a beam splitter for redirecting a fraction of each said delay line signal;

a lens located at an output of said beam splitter for coupling each said fractional delay line signal into a lens output;

an optical detector disposed adjacent to said lens and receiving said lens output, said detector combining said fractional delay line signals to create a net signal;

a processor having an input for receiving said net signal from said optical detector and means for generating each one of said control signals by independently determining an optimal modulation value of said wave component of one said corresponding delay line signal, wherein a value of said control signal corresponds to an adjustment in power of said net signal; and

an output for outputting said plurality of control signals.

12. An optical transmission system as recited in claim 11, wherein said means for generating said control signals comprises:

a plurality of servo control loops, each one of said servo control loops providing wave component feedback information for one corresponding said delay line, each servo control loop generating said corresponding control signal from said feedback information and a corresponding weight value.

13. An optical transmission system as recited in claim 12, wherein each said servo control loop is an orthogonally CDMA encoded servo control loop.

14. An optical transmission system, comprising:

a source for transmitting an input optical signal;

an optical array having a primary input for receiving said optical signal;

a plurality of delay lines, each said delay line having an input, an output, and a predetermined optical path length;

an optical splitter coupled to said primary input for splitting said input optical signal into a plurality of delay line signals, each of said delay line signals being input to one corresponding delay line input and each said delay carries its respective delay line signal to a destination point located at said delay line outputs;

means for producing a plurality of control signals, utilizing orthogonal code modulation, to control the modulation of an optical wave component of each said delay line signal;

means for modulating each said delay line optical wave component according to said corresponding control signal;

a plurality of microlenses, each one of said microlenses providing a optical focusing of one corresponding said delay line signal output; and

a plurality of optical amplifiers, each one of said amplifiers providing optical amplification of one corresponding said delay line signal;

wherein said means for producing a plurality of control signals comprises a processor for receiving electrical signals derived from output optical signals sampled at said delay line outputs, and for generating therefrom each one of said control signals by independently determining an optimal modulation value of said optical wave component of each of said corresponding delay line signals;

and further comprising a plurality of conjugate phase adjustors, each one of said conjugate phase adjustors imposing a point conjugate solution on the phase of one corresponding said delay line signal.