Method of generation of two electromagnetic modes using squeezers

• US 5,353,362 A
• Filed: 05/17/1993
• Issued: 10/04/1994
• Est. Priority Date: 05/17/1993
• Status: Expired due to Fees

• Current Assignee: Tucci, Robert R.
• Original Assignee: Tucci, Robert R.
• Inventors: Tucci, Robert R.
• Primary Examiner(s): Healy, Brian
• Application Number:
  US08/062,316
• Time in Patent Office: 505 Days
• Field of Search: 385/27, 385/28, 385/11, 385/29, 385/24, 385/30, 385/31, 385/42, 385/3, 385/13, 385/15, 250/227.11, 359/115, 359/116, 359/122, 356/345, 356/351, 356/359
• US Class Current: 385/27
• CPC Class Codes: G01J 9/02 by interferometric methods using interferometers for measuring optically the linear dimensions of objects G01B9/02

Abstract

A device, referred to as a covmuter, transforms two initial electromagnetic modes into two final ones. The probabilistic fluctuations of the amplitudes of the initial pair of modes are characterized by an initial covariance matrix. Similarly, the final pair of modes is attributed a final covariance matrix. We show how a covmuter can be used to produce a final pair of modes possessing any desired covariance matrix. We also show how a covmuter can be used to measure the covariance matrix of any initial pair of modes. Simplified covmuter devices that result from omitting some of the components of the covmuter and some uses of such simplified covmuters are also presented. The invention applies both in the quantum mechanical and classical regimes.

Claims

1. A method for transforming a travelling electromagnetic wave comprising two initial modes lying in an initial 2-mode state into a travelling electromagnetic wave comprising two final modes lying in a final 2-mode state, said method comprising the steps of:

STEP (1) obtaining said two initial modes, and using them as the two input modes for the next step,

STEP (2) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step,

STEP (3) inducing a mutual squeezer to transform the two input modes for this step into the two input modes for the next step,

STEP (4) inducing a mode coupler to transform the two input modes for this step into the two input modes for the next step,

STEP (5) obtaining the two input modes for this step, and identifying them as said two final modes.

2. A method for transforming a travelling electromagnetic wave comprising two initial modes lying in an initial 2-mode state into a travelling electromagnetic wave comprising two final modes lying in a final 2-mode state, said method comprising the steps of:

STEP (1) obtaining said two initial modes, and using them as the two input modes for the next step,

STEP (2) inducing a mutual squeezer to transform the two input modes for this step into the two input modes for the next step,

STEP (3) inducing a mode coupler to transform the two input modes for this step into the two input modes for the next step,

STEP (4) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step,

STEP (5) obtaining the two input modes for this step, and identifying them as said two final modes.

3. The method of claim 2, comprising additional Steps 6, 7 and 8 to be performed between Steps 1 and 2, and comprising additional Step 9, to be performed between Steps 2 and 3, and comprising additional Step 10, to be performed between Steps 3 and 4, and comprising additional Step 11, to be performed between Steps 4 and 5, said additional steps being as follows:

STEP (6) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step,

STEP (7) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step, said one mode acted upon in this step coming from the input mode for Step 6 which was not acted upon by said self-squeezer in Step 6,

STEP (8) procuring the action of phase shifting means for multiplying one of the two input modes for this step by a unit modulus complex number, and procuring the action of phase shifting means for multiplying the other of said two input modes for this step by a unit modulus complex number, to produce the two input modes for the next step,

STEP (9) procuring the action of phase shifting means for multiplying one of the two input modes for this step by a unit modulus complex number, and procuring the action of phase shifting means for multiplying the other of said two input modes for this step by a unit modulus complex number, to produce the two input modes for the next step,

STEP (10) procuring the action of phase shifting means for multiplying one of the two input modes for this step by a unit modulus complex number, and procuring the action of phase shifting means for multiplying the other of said two input modes for this step by a unit modulus complex number, to produce the two input modes for the next step,

STEP (11) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step, said one mode acted upon in this step coming from the input mode to Step 4 which was not acted upon by said self-squeezer in Step 4.

4. The method of claim 3, wherein said final 2-mode state has the desired covariance parameters, wherein said initial 2-mode state is a diagonal 2-mode state, and comprising additional Steps 12 and 13 to be performed before Step 1, and comprising additional Steps 14 and 15 to be performed between Steps 11 and 5, said additional steps being as follows:

STEP (12) calculating from said desired covariance parameters, the required values for;

the two noise intensities of said initial 2-mode state, the characteristic parameters of the mode coupler, the mutual squeezer and the self-squeezers to be used in Steps 6, 7, 2, 3, 4 and 11,

STEP (13) procuring the action of generating means for generating a diagonal 2-mode state possessing said noise intensities calculated in Step 12, and using the two modes of said diagonal 2-mode state as said two initial modes,

STEP (14) varying the characteristic parameters of said mode coupler, of said mutual squeezer and of all said self-squeezers, until agreement with said required values that were calculated in Step 12 is achieved,

STEP (15) varying the phase shifting means used in Steps 8, 9 and 10, until satisfaction is achieved of certain angular constraints between the phase shifts produced in Steps 8, 9 and 10, the satisfaction of said angular constraints being a prerequisite for said required values calculated in Step 12 to be applicable.

5. The method of claim 3, wherein said final 2-mode state is a diagonal 2-mode state, and comprising additional Step 12 to be performed between Steps 11 and 5, said additional step being as follows:

STEP (12) varying the characteristic parameters of said mode coupler, of said mutual squeezer and of all said self-squeezers, until certain extremum conditions are satisfied among the noise intensities of the two output modes of said mutual squeezer, of said mode coupler and of said self-squeezers, said extremum conditions being such that their satisfaction guarantees that said final state is a diagonal 2-mode state.

6. The method of claim 5, whereby the covariance parameters of said initial state can be measured, comprising additional Step 13 to be performed between Steps 11 and 12, and comprising additional Steps 14 and 15 to be performed between Steps 12 and 5, said additional steps being as follows:

STEP (13) varying the phase shifting means used in Steps 8, 9 and 10, until satisfaction is achieved of certain angular constraints between the phase shifts produced in Steps 8, 9 and 10, the satisfaction of said angular constraints being a prerequisite for the calculations of Step 15 to be applicable,

STEP (14) collecting, after Step 12 is completed, the following data;

the noise intensities of said two final modes, and the characteristic parameters of said mode coupler, of said mutual squeezer and of all said self-squeezers,

STEP (15) calculating said covariance parameters of said initial 2-mode state using said data collected in Step 14.

7. A method for transforming a travelling electromagnetic wave comprising two initial modes lying in an initial 2-mode state into a travelling electromagnetic wave comprising two final modes lying in a final 2-mode state, said method comprising the steps of:

STEP (1) obtaining said two initial modes, and using them as the two input modes for the next step,

STEP (2) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step,

STEP (3) inducing a mode coupler to transform the two input modes for this step into the two input modes for the next step,

STEP (4) inducing a mutual squeezer to transform the two input modes for this step into the two input modes for the next step,

STEP (5) obtaining the two input modes for this step, and identifying them as said two final modes.

8. A method for transforming a travelling electromagnetic wave comprising two initial modes lying in an initial 2-mode state into a travelling electromagnetic wave comprising two final modes lying in a final 2-mode state, said method comprising the steps of:

STEP (1) obtaining said two initial modes, and using them as the two input modes for the next step,

STEP (2) inducing a mode coupler to transform the two input modes for this step into the two input modes for the next step,

STEP (3) inducing a mutual squeezer to transform the two input modes for this step into the two input modes for the next step,

STEP (4) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step,

STEP (5) obtaining the two input modes for this step, and identifying them as said two final modes.

9. The method of claim 8, comprising additional Steps 6, 7 and 8 to be performed between Steps 1 and 2, and comprising additional Step 9, to be performed between Steps 2 and 3, and comprising additional Step 10, to be performed between Steps 3 and 4, and comprising additional Step 11, to be performed between Steps 4 and 5, said additional steps being as follows:

STEP (6) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step,

STEP (7) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step, said one mode acted upon in this step coming from the input mode for Step 6 which was not acted upon by said self-squeezer in Step 6,

STEP (8) procuring the action of phase shifting means for multiplying one of the two input modes for this step by a unit modulus complex number, and procuring the action of phase shifting means for multiplying the other of said two input modes for this step by a unit modulus complex number, to produce the two input modes for the next step,

STEP (9) procuring the action of phase shifting means for multiplying one of the two input modes for this step by a unit modulus complex number, and procuring the action of phase shifting means for multiplying the other of said two input modes for this step by a unit modulus complex number, to produce the two input modes for the next step,

STEP (10) procuring the action of phase shifting means for multiplying one of the two input modes for this step by a unit modulus complex number, and procuring the action of phase shifting means for multiplying the other of said two input modes for this step by a unit modulus complex number, to produce the two input modes for the next step,

STEP (11) inducing a self-squeezer to act on one of the two input modes for this step, to produce the two input modes for the next step, said one mode acted upon in this step coming from the input mode to Step 4 which was not acted upon by said self-squeezer in Step 4.

10. The method of claim 9, wherein said final 2-mode state has the desired covariance parameters, wherein said initial 2-mode state is a diagonal 2-mode state, and comprising additional Steps 12 and 13 to be performed before Step 1, and comprising additional Steps 14 and 15 to be performed between Steps 11 and 5, said additional steps being as follows:

STEP (12) calculating from said desired covariance parameters, the required values for;

the two noise intensities of said initial 2-mode state, the characteristic parameters of the mode coupler, the mutual squeezer and the self-squeezers to be used in Steps 6, 7, 2, 3, 4 and 11,

STEP (13) procuring the action of generating means for generating a diagonal 2-mode state possessing said noise intensities calculated in Step 12, and using the two modes of said diagonal 2-mode state as said two initial modes,

STEP (14) varying the characteristic parameters of said mode coupler, of said mutual squeezer and of all said self-squeezers, until agreement with said required values that were calculated in Step 12 is achieved,

STEP (15) varying the phase shifting means used in Steps 8, 9 and 10, until satisfaction is achieved of certain angular constraints between the phase shifts produced in Steps 8, 9 and 10, the satisfaction of said angular constraints being a prerequisite for said required values calculated in Step 12 to be applicable.

11. The method of claim 9, wherein said final 2-mode state is a diagonal 2-mode state, and comprising additional Step 12 to be performed between Steps 11 and 5, said additional step being as follows:

STEP (12) varying the characteristic parameters of said mode coupler, of said mutual squeezer and of all said self-squeezers, until certain extremum conditions are satisfied among the noise intensities of the two output modes of said mutual squeezer, of said mode coupler and of said self-squeezers, said extremum conditions being such that their satisfaction guarantees that said final state is a diagonal 2-mode state.

12. The method of claim 11, whereby the covariance parameters of said initial state can be measured, comprising additional Step 13 to be performed between Steps 11 and 12, and comprising additional Steps 14 and 15 to be performed between Steps 12 and 5, said additional steps being as follows:

STEP (13) varying the phase shifting means used in Steps 8, 9 and 10, until satisfaction is achieved of certain angular constraints between the phase shifts produced in Steps 8, 9 and 10, the satisfaction of said angular constraints being a prerequisite for the calculations of Step 15 to be applicable,

STEP (14) collecting, after Step 12 is completed, the following data;

the noise intensities of said two final modes, and the characteristic parameters of said mode coupler, of said mutual squeezer and of all said self-squeezers,

STEP (15) calculating said covariance parameters of said initial 2-mode state using said data collected in Step 14.

13. A method of transforming a travelling electromagnetic wave comprising two initial modes into a travelling electromagnetic wave comprising two final modes, whereby the mutual squeezing parameter of said two initial modes can be measured, said method comprising the steps of:

(1) obtaining said two initial modes, and using them as the two input modes for the next step,

(2) inducing a mutual squeezer to transform the two input modes for this step into the two input modes for the next step,

(3) obtaining the two input modes for this step, and identifying them as said two final modes,

(4) varying the characteristic parameters of said mutual squeezer until the noise intensity of one of said two final modes is minimized,

(5) collecting, after Step (4) is completed, the following data;

the noise intensities of said two final modes, and the characteristic parameters of said mutual squeezer,

(6) calculating said mutual-squeezing parameter of said two initial modes using said data collected in Step (5).

14. A method of transforming a travelling electromagnetic wave comprising an initial mode into a travelling electromagnetic wave comprising a final mode, whereby the self-squeezing parameter of said initial mode can be measured, said method comprising the steps of:

(1) obtaining said initial mode, and using it as the input mode for the next step,

(2) inducing a self-squeezer to transform the input mode for this step into the input mode for the next step,

(3) obtaining the input mode for this step, and identifying it as said final mode,

(4) varying the characteristic parameters of said self-squeezer until the noise intensity of said final mode is minimized,

(5) collecting, after Step (4) is completed, the following data;

the noise intensity of said final mode, and the characteristic parameters of said self-squeezer,

(6) calculating said self-squeezing parameter of said initial mode using said data collected in Step (5).

15. A method of transforming a travelling electromagnetic wave comprising two initial modes into a travelling electromagnetic wave comprising two final modes, whereby the N₁₂ parameter of said two initial modes can be measured, said method comprising the steps of:

(1) obtaining said two initial modes, and using them as the two input modes for the next step,

(2) inducing a mode coupler to transform the two input modes for this step into the two input modes for the next step,

(3) obtaining the two input modes for this step, and identifying them as said two final modes,

(4) varying the characteristic parameters of said mode coupler until the larger of the two noise intensities of said two final modes is maximized,

(5) collecting, after Step (4) is completed, the following data;

the noise intensities of said two final modes, and the characteristic parameters of said mode coupler,

(6) calculating said N₁₂ parameter of said two initial modes using said data collected in Step (5).