1. An amino-acid iodine complex comprising an iodine molecule complexed with a plurality of amino acids such that the iodine molecule is at a coordinate center between first and second of said plurality of amino acids with the iodine molecule being complexed to the first and second amino acids at respective amino groups and carboxyl groups of the first and second amino acids, the complex being of general formula (I)
wherein R1 and R2 may be the same or different and represent side-chain groups of amino-acids, m and n may be the same or different and represent the number of amino-acids in the complex, respectively; and wherein m and n are such that the molecular ratio of amino acid to iodine in the complex is from 2 to 20.
2. The amino-acid iodine complex according to claim 1, wherein the first and second amino acids are simple amino-acids.
3. The amino-acid iodine complex according to claim 2, wherein said simple amino-acids are selected from the group consisting of alanine (Ala), arginine (Arg), asparagine (Asn), aspartic acid (Asp), cysteine (Cys), glutamine (Gln), glutamic acid (Glu), glycine (Gly), histidine (His), isoleucine (lle), leucine (Leu), lysine (Lys), methionine (Met), phenylalanine (Phe), proline (Pro), serine (Ser), threonine (Thr), tryptophan (Trp), tyrosine (Tyr) and valine (Val).
4. The amino-acid iodine complex according to claim 1, wherein at least said first amino acid is a derivative of a simple amino-acid.
5. The amino-acid iodine complex according to claim 1, wherein at least said first amino acid is formed by simple amino-acids, or multiple amino-acids produced by hydrolyzing animal or plant protein.
6. The amino-acid iodine complex according to claim 1, wherein the iodine molecule at the coordinate center comprises a radioactive isotope.
7. The amino-acid iodine complex according to claim 1, wherein the molecular ratio of amino-acid to iodine is from 2 to 5.
8. The amino-acid iodine complex according to claim 1, wherein the first and second amino acids are methionine, and the molecular ratio of methionine to iodine is 2:1.
9. A method for preparing an amino-acid iodine complex of claim 1, comprising forming an amino-acid amino-carboxyl iodine complex by opening inner-complex ring of amino-acid with an acid catalyst and complexing with the iodine molecule, under suitable conditions of time, medium, temperature and pH value.
10. The method for preparing the amino-acid iodine complex according to claim 9, wherein said acid catalyst is an inorganic acid.
11. The method for preparing the amino-acid iodine complex according to claim 10, wherein said inorganic acid is selected from the group consisting of phosphoric acid, hydrochloric acid and sulfuric acid, said organic acid is selected from citric acid, acetic acid, fumaric acid and lactic acid.
12. The method for preparing the amino-acid iodine complex according to claim 9, wherein the medium comprises water, ethanol, petroleum ether, benzyl alcohol and ethyl acetate.
13. The method for preparing the amino-acid iodine complex according to claim 9, wherein the pH value is from about 1 to 5, the temperature is from about 25 to 85\xb0 C., and the time is for a period of from about 30 to 300 mins.
14. The method for preparing the amino-acid iodine complex according to claim 9, wherein said pH value is maintained at a level of from about 2 to 3, said temperature being controlled at from about 40\xb0 C. to 50\xb0 C., and the time is from about 150 to 200 mins.
15. A composition of disinfectant, comprising the amino-acid iodine complex according to claim 1.
16. A composition of feedstuff, comprising the amino-acid iodine complex according to claim 1.
17. The amino-acid iodine complex according to claim 2, wherein at least said first amino acid is a derivative of a simple amino-acid.
18. The amino-acid iodine complex according to claim 2, wherein at least said first amino acid is formed by simple amino-acids or multiple amino-acids produced by hydrolyzing animal or plant protein.
19. A method for disinfecting an article comprising applying the complex of claim 1 to the article.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of measuring cumulative polarization mode dispersion (PMD) along the length of a fiber-under-test (FUT) using a single-end polarization sensitive optical time domain reflectometer means (POTDR), the method characterized by the steps of:
(i) injecting into an end of the FUT a first group of at least two series of light pulses having at least two different wavelengths, respectively, each of said at least two different wavelengths being closely-spaced from the or each of the other wavelengths by a respective small wavelength step corresponding to a respective small optical frequency difference, the lowermost and uppermost of said at least two wavelengths defining therebetween a first center wavelength (\u03bb1) for said first group, the at least two series of light pulses of the first group having the same state of polarization (SOP1);
(ii)(a) for each of at least some of the light pulses in each series of light pulses, detecting at least one polarization component of the resulting back reflected signal caused by Rayleigh scattering andor discrete reflections along the FUT to provide a corresponding impulse-response, said at least one polarization component being the same for each of the said series, and converting each of the impulse-responses into a corresponding electrical impulse-response signal,
(ii)(b) for each series of light pulses of said first group, sampling and averaging the electrical impulse-response signals of said each of at least some of the light pulses to provide a corresponding first group of OTDR traces each representing detected backscattered power versus time for the corresponding series of light pulses in said first group;
(iii) injecting into said FUT at least a second group of at least two series of light pulses having at least two different wavelengths, respectively, each of said at least two different wavelengths being separated by a small optical frequency difference equal to the corresponding said small optical frequency difference of the said first group, lowermost and uppermost of said at least two wavelengths defining therebetween a second center wavelength (\u03bb2) for said second group, the at least two series of light pulses of the second group having the same state of polarization (SOP2) as each other; and wherein either or both of said state of polarization (SOP2) and center wavelength (\u03bb2) of said second group differ from those of the first group of series of light pulses;
(iv)(a) for each of at least some of the light pulses in each of the at least two series of light pulses in said second group, detecting at least one polarization component of the resulting backreflected signal caused by Rayleigh scattering andor discrete reflections along the FUT to provide a corresponding impulse-response, said at least one polarization component being the same for each of the said series of light pulses of said second group, and converting each of the impulse-responses into a corresponding electrical impulse-response signal,
(iv)(b) for each series of light pulses of said second group, sampling and averaging the electrical impulse-response signals of said each of at least some of the light pulses to provide a corresponding second group of OTDR traces each representing detected backscattered power versus time for the corresponding series of light pulses in said second group; and
(v) computing:
(a) an average OTDR trace from the OTDR traces in the first group of OTDR traces and the second group of OTDR traces, and dividing each of the OTDR traces by the said average OTDR trace, point by point, to obtain a first group of normalized OTDR traces and a second group of normalized OTDR traces,
(b) the difference, point-by-point temporally, between the or each pair of normalized OTDR traces at different wavelengths in each of the first and second groups of normalized OTDR traces,
(c) for at least one temporal point, the mean-square value of said differences to obtain a mean-square difference with respect to time, and
(vi) computing the cumulative PMD value at least one specific distance z along the FUT corresponding to the said at least one temporal point as a predetermined function of said mean-square difference, said predetermined function being dependent upon the respective difference or differences between the wavelengths corresponding to the traces in each said pair thereof.
2. A method according to claim 1, characterized in that step (v) includes the steps of computing:
(d) the relative variance of the normalized OTDR traces, point by point temporally, and
(e) the ratio of the mean-square difference over the relative variance, point-by-point;
and wherein step (vi) then computes the cumulative PMD as a function of said ratio.
3. A method according to claim 5, characterized in that the step (i) of injecting said first group of at least two series of light pulses includes injecting at least one additional series of light pulses having a wavelength (\u03bb1I) intermediate said first uppermost wavelength (\u03bb1U) and said first lowermost wavelength (\u03bb1L) and having the same state of polarization (SOP1), said intermediate wavelength being unequally spaced from the lowermost and uppermost wavelengths, respectively, and said step of injecting into said FUT a second group of at least two series of light pulses having either or both of a different state of polarization (SOP2) and a different center wavelength (\u03bb2), as compared with the first group of at least two series of light pulses, includes injecting at least one additional series of light pulses having a wavelength intermediate the respective wavelengths of the series of light pulses of the second group and unequally spaced therefrom, wherein optical frequency differences between corresponding series of light pulses in said first group and second group, respectively, are equal, the impulse responses of the light pulses of each additional series being processed in a similar manner to the impulse responses of the pulses at the associated uppermost and lowermost wavelengths.
4. A method according to claim 5, characterized in that each group of two or more series of light pulses comprises a duplicate of each of said two or more series of light pulses, the computed OTDR traces including traces for the duplicate series of light pulses.
5. A method according to claim 1, characterized in that said at least a second group in step (iii) comprises a relatively large number of additional said groups each of at least two series of light pulses, each group of additional series of light pulses having either or both of a different state of polarization and a different center wavelength, and computing steps (v) and (vi) compute said cumulative PMD from at least one pair of normalized OTDR traces in the said first group and the corresponding at least one pair of normalized OTDR traces in each of the said relatively large number of additional said groups.
6. A method according to claim 5, characterized in that the number of different states of polarization andor wavelengths is at least 10.
7. A method according to claim 5, characterized in that the number is at least 200.
8. A method according to claim 5, characterized in that points representing the states of polarization of the series of light pulses on the Poincar\xe9 sphere are uniformly-distributed over the surface of the sphere.
9. A method according to claim 2, characterized in that each of the light pulses has a duration that is equal to or longer than the minimum beat-length of the FUT.
10. A method according to claim 5, characterized in that each of the light pulses has a duration that is less than 0.1 times the minimum beat-length of the FUT.
11. Polarization optical time domain reflectometer means characterized by:
(i) optical means (10, 20) for:
(a) providing groups of series of light pulses and controlling wavelength and state of polarization of each of said series of light pulses so that
(1) light pulses in a particular series have the same wavelength;
(2) all series of light pulses in a particular group have the same state of polarization;
(3) each group of series of light pulses has either or both of a different centre wavelength and a different state of polarization as compared with each other group;
(b) injecting each of said groups of series of light pulses into an end of a fiber-under-test (FUT 16), and
(c) extracting from the FUT, for each of at least some of the light pulses in each series of light pulses, at least one polarization component of the resulting backreflected signal caused by Rayleigh scattering andor discrete reflections along the FUT to provide a corresponding impulse-response, said at least one polarization component being the same for each of the said series in a particular group;
(ii) detector means (26) for converting each of the impulse-responses into a corresponding electrical impulse-response signal,
(iii) sampling and averaging means (28) for sampling and averaging all of the electrical impulse-response signals of said each of at least some of the light pulses to provide an OTDR trace representing detected backscattered power versus time for each series of light pulses;
(iv) control and processing means (30,32) for controlling the optical means (10, 20) and said sampling and averaging means (28) so as to:
(A) cause said optical means (10,20) to inject into an end of the FUT a first group of at least two series of light pulses having at least two different wavelengths, respectively, each of said at least two different wavelengths being closely-spaced from the or each of the other wavelengths by a respective small wavelength step corresponding to a respective small optical frequency difference, the lowermost wavelength (\u03bb1L) and uppermost wavelength (\u03bb1U), respectively, of said at least two wavelengths defining therebetween a first center wavelength (\u03bb1) for said first group, the at least two series of light pulses of the first group having the same state of polarization (SOP1);
(B) cause the optical means (10,20) to extract, for each of at least some of the light pulses in each of said at least two series of light pulses in said first group, at least one polarization component of the resulting backreflected signal caused by Rayleigh scattering andor discrete reflections along the FUT to provide a corresponding impulse-response, said at least one polarization component being the same for each of the said series of light pulses of said first group, and cause said detection means (26) to convert each of the impulse-responses into a corresponding electrical impulse-response signal,
(C) for each series of light pulses in said first group, cause the sampling and averaging means (28) to sample the electrical impulse-response signals of said each of at least some of the light pulses to provide a corresponding first group of OTDR traces each representing detected backscattered power versus time for the corresponding series of light pulses of said first group;
(D) cause said optical means (10,20) to inject into an end of the FUT a second group of at least two series of light pulses having at least two different wavelengths, respectively, each of said at least two different wavelengths of the second group being separated by a small optical frequency difference equal to the corresponding said small optical frequency difference of the said first group, lowermost and upper most of said at least two wavelengths defining therebetween a second center wavelength (\u03bb2) for said second group, the at least two series of light pulses of the second group having the same state of polarization (SOP2) as each other, and wherein either or both of said state of polarization (SOP2) and a center wavelength (\u03bb2) of said second group differ from those of said first group of at least two series of light pulses,
(E) cause the optical means (10,20) to extract, for each of at least some of the light pulses in each of the at least two series of light pulses in said second group, at least one polarization component of the resulting backreflected signal caused by Rayleigh scattering andor discrete reflections along the FUT to provide a corresponding impulse-response, said at least one polarization component being the same for each of the said series of light pulses of said second group, and cause said detection means (26) to convert each of the impulse-responses into a corresponding electrical impulse-response signal,
(F) for each series of light pulses of said second group, cause the sampling and averaging means (28) to sample and average the electrical impulse-response signals of said each of at least some of the light pulses to provide a corresponding second group of OTDR traces each representing detected backscattered power versus time for the corresponding series of light pulses of said second group;
the control and computing means (30,32) being operable to compute:
(a) an average OTDR trace from the OTDR traces in the first group of OTDR traces and the second group of OTDR traces, and divide each of the OTDR traces by the said average OTDR trace, point by point, to obtain a first group of normalized OTDR traces and a second group of normalized OTDR traces,
(b) in each of the first and second groups of normalized OTDR traces, the difference, point-by-point temporally, between the or each pair of normalized OTDR traces, the OTDR traces in each pair corresponding to different wavelengths,
(c) for at least one temporal point, the mean-square value of said differences to obtain a mean-square difference with respect to time, and
(d) the cumulative PMD value at least one specific distance z along the FUT corresponding to the said at least one temporal point as a predetermined function of said mean-square difference, said predetermined function being dependent upon the difference or differences between the wavelengths corresponding to said normalized OTDR traces in each pair thereof.
12. Polarization optical time domain reflectometer means according to claim 19, characterized in that said control and computing means (10,20) uses a said predetermined function that is selected for the case where the product (PMD\xb7\u03b4\u03bd) of the cumulative PMD and the optical frequency difference (\u03b4\u03bd) corresponding to said wavelength difference is in the range from relatively small to relatively large.
13. Polarization optical time domain reflectometer means according to claim 12 characterized in that said range is from PMD\xb7\u03b4\u03bd<0.01 to at least PMD\xb7\u03b4\u03bd\u02dc0.15.
14. Polarization optical time domain reflectometer means according to claim 12, characterized in that the cumulative PMD is computed according to the arcsine formula,
PMD
=
3
8
\ue89e
1
\u03c0
\ue89e
\ue89e
\u03b4
\ue89e
\ue89e
v
\ue89e
arc
\ue89e
\ue89e
sin
\ue8a0
(
5
8
\ue89e
\u3008
\u0394
\ue89e
\ue89e
P
2
\u3009
SOP
;
\u03bb
\u03c3
r
2
)
15. Polarization optical time domain reflectometer means according to claim 11, characterized in that said optical means (10,20) comprises a polarizer (22) and a SOP controller (24) and each series of light pulses passes through said polarizer (22) and SOP controller (24) in the direction towards the FUT and the corresponding backreflected signal passes through the SOP controller (24) and the polarizer (22) in an opposite direction towards the detector means (26).
16. Polarization optical time domain reflectometer means according to claim 19, characterized in that the computing means is operable to compute the relative variance of the normalized traces, point by point temporally, and the ratio of the mean-square difference over the relative variance, point-by-point, then compute said cumulative PMD as a function of said ratio.
17. Polarization optical time domain reflectometer means according to claim 19, characterized in that the control means is operable to cause said optical means (10,20), in addition to injecting said first group of at least two series of light pulses, to inject into said FUT at least one additional series of light pulses having a wavelength (\u03bb1I) intermediate said first uppermost wavelength (\u03bb1U) and said first lowermost wavelength (\u03bb1L) and having the same state of polarization (SOP1), said intermediate wavelength being unequally spaced from the lowermost and uppermost wavelengths, respectively, and when injecting into said FUT a second group of at least two series of light pulses having either or both of a different state of polarization (SOP2) and a different center wavelength (\u03bb2), as compared with the first group of at least two series of light pulses, to inject at least one additional series of light pulses having a wavelength intermediate the respective wavelengths of the series of light pulses of the second group and unequally spaced therefrom, the detecting and averaging means and the computing means being operable to detect and process the impulse responses of the pulses in the additional series along with the impulse responses of the pulses at the associated uppermost and lowermost wavelengths.
18. Polarization optical time domain reflectometer means according to claim 11, characterized in that said optical means (10, 20) is caused to inject as part of each group of two or more series of light pulses a duplicate of each of said series of light pulses at a first lowermost wavelength and said series of light pulses at a first uppermost wavelength, the computing means then computing said OTDR traces including traces for the duplicate series of light pulses.
19. Polarization optical time domain reflectometer means according to claim 11, characterized in that said at least a second group of series of light pulses comprises a relatively large number of additional said groups of at least two series of light pulses, each group of additional series of light pulses having either or both of a different state of polarization and a different center wavelength, and the computing means computes said cumulative PMD from at least one pair of normalized OTDR traces in the said first group and the corresponding at least one pair of normalized OTDR traces in each of the said relatively large number of additional said groups.
20. Polarization optical time domain reflectometer means according to claim 11, characterized in that said polarization controller includes a polarizer (22) for selecting the state of polarization of the series of light pulses entering the FUT (16) and selecting said polarization component for detecting the corresponding backreflected signals leaving the FUT.
21. (canceled)
22. (canceled)
23. Polarization optical time domain reflectometer means according to claim 19, characterized in that points representing the states of polarization of the said relatively large number of groups of at least two series of light pulses on the Poincar\xe9 sphere are substantially uniformly-distributed over the surface of the sphere.
24. Polarization optical time domain reflectometer means according to claim 16, characterized in that each of the light pulses has a duration that is equal to or longer than the minimum beat-length of the FUT.
25. Polarization optical time domain reflectometer means according to claim 11, characterized in that each of the light pulses has a duration that is less than 0.1 times the minimum beat-length of the FUT.
26. A method of measuring cumulative polarization mode dispersion (PMD) along the length of a fiber-under-test (FUT), using a single-end polarization sensitive optical time domain reflectometer (POTDR), characterized in that the POTDR is used to inject into an end of the FUT plural series of light pulses arranged in several groups; each group comprising at least two series of light pulses having different but closely-spaced wavelengths defining a centre wavelength and having the same SOP; a large number of such groups being injected and a corresponding OTDR trace obtained for each of the series of light pulses in the large number of groups by averaging the impulse-response signals of the light pulses in that particular series, thereby obtaining a corresponding large number of groups of OTDR traces, wherein each group of series has a different centre wavelength andor SOP as compared with other groups of series; the cumulative PMD, as a function of distance z along the FUT, being obtained by normalizing the large number of groups of OTDR traces to obtain a large number of groups of normalized OTDR traces, computing the difference, point by point, between the or each pair of normalized OTDR traces at different wavelengths in each group of normalized OTDR traces, followed by the mean-square value of these several differences, at least one temporal point, to obtain a mean-square difference as a function of time and, finally, computing the cumulative PMD at least one specific distance z along the FUT corresponding to the said at least one temporal point as a predetermined function of said mean-square difference, said predetermined function being dependent upon the respective difference or differences between the wavelengths corresponding to said normalized OTDR traces in each said pair thereof.
27. A method according to claim 5, characterized in that said predetermined function is selected for the case where the product of the cumulative PMD (PMD\xb7\u03b4\u03bd) and the optical frequency difference (\u03b4\u03bd) corresponding to said wavelength difference is in the range from relatively small to relatively large.
28. A method according to claim 27, characterized in that said range is from PMD\xb7\u03b4\u03bd<0.01 to at least PMD\xb7\u03b4\u03bd\u02dc0.15.
29. A method according to claim 27, characterized in that the cumulative PMD is computed according to the arcsine formula,
PMD
=
3
8
\ue89e
1
\u03c0
\ue89e
\ue89e
\u03b4
\ue89e
\ue89e
v
\ue89e
arc
\ue89e
\ue89e
sin
\ue8a0
(
5
8
\ue89e
\u3008
\u0394
\ue89e
\ue89e
P
2
\u3009
SOP
;
\u03bb
\u03c3
r
2
)
30. A method according to claim 1, characterized in that a large number of such groups are injected and corresponding OTDR traces obtained and processed
31. A method according to claim 1, characterized in that the backreflected light comprises Fresnel-backreflection from the distal end of the FUT, and the measured cumulative PMD comprises the overall PMD of the FUT.
32. Polarization optical time domain reflectometer means according to claim 19, characterized in that the detecting means detects Fresnel-backreflection from the distal end of the FUT and the computing means determines overall PMD of the FUT.
33. A method according to claim 5, characterized in that step (v) includes the steps of computing:
(d) the relative variance of the normalized OTDR traces, point by point temporally, and
(e) the ratio of the mean-square difference over the relative variance, point-by-point;
and wherein step (vi) then computes the cumulative PMD as a function of said ratio.