EQUIPMENT AND METHOD FOR MEASURING CROSSTALK BETWEEN CORES OF AN OPTICAL FIBER HAVING MULTIPLE CORES

1 . An apparatus for measuring inter-core crosstalk comprising:

means for injecting a laser beam into one core of an optical fiber having a plurality of cores;

means for converting light emitted from each of the cores provided in the optical fiber into parallel light with an angle difference;

electric field intensity distribution measuring means capable of measuring an intensity distribution of an interference waveform of the parallel light;

interference waveform analysis means capable of independently obtaining an interference component between the one core and any core, different from the one core, provided in the optical fiber and a DC component other than the interference component using the measured intensity distribution of the interference waveform; and

crosstalk analysis means capable of obtaining crosstalk from the one core to any core, different from the one core, using the interference component and the DC component.

2 . The apparatus for measuring inter-core crosstalk according to claim 1 , further comprising: means for converting light emitted from a core disposed at a center of the optical fiber into parallel light parallel to a central axis of the optical fiber.

3 . The apparatus for measuring inter-core crosstalk according to claim 1 , wherein the interference waveform analysis means obtains a two-dimensional spatial frequency spectrum from the interference waveform, and

obtains the interference component and the DC component by extracting a frequency component obtained from the two-dimensional spatial frequency spectrum.

4 . The apparatus for measuring inter-core crosstalk according to claim 3 , wherein the interference waveform analysis means

obtains the DC component by extracting a frequency component, located at an origin, obtained from the two-dimensional spatial frequency spectrum, and

obtains the interference component by extracting a frequency component, located at a position other than the origin, obtained from the two-dimensional spatial frequency spectrum.

5 . The apparatus for measuring inter-core crosstalk according to claim 3 , wherein the interference waveform analysis means obtains a two-dimensional spatial frequency spectrum by performing a two-dimensional Fourier transform on the interference waveform.

6 . A method for measuring inter-core crosstalk of an optical fiber having a plurality of cores, the method comprising:

injecting light into one core of the optical fiber;

converting light emitted from each of the cores provided in the optical fiber into parallel light with an angle difference;

measuring an intensity distribution of an interference waveform of the parallel light;

independently obtaining an interference component between the one core and any core, different from the one core, provided in the optical fiber and a DC component other than the interference component using the interference waveform of the parallel light; and

obtaining crosstalk from the one core to any core, different from the one core, using the interference component and the DC component.

7 . The method for measuring inter-core crosstalk according to claim 6 , further comprising: converting light emitted from a core disposed at a center of the optical fiber into parallel light parallel to a central axis of the optical fiber.