Optical fiber evaluation method and optical fiber evaluation apparatus
AssigneeNippon Telegraph and Telephone Corporation
InventorsTomokazu Oda, Hiroyuki Oshida, Daisuke Iida, Atsushi Nakamura, Yuto Sagae
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Abstract
An optical fiber testing method is presented for measuring the change amount for the wave number k of a Brillouin Frequency Shift ν in stimulated Brillouin scattering generated in the same acoustic mode with respect to each target propagation mode. In this way, the ratio of the change amount measured at each propagation mode is acquired as the group delay ratio between the modes.
Claims6
An optical fiber testing method for evaluating a group delay ratio between modes of an optical fiber to be measured, the method comprising:
- measuring a change amount for wave number in a Brillouin Frequency Shift for each two propagation modes having same acoustic mode excited when stimulated Brillouin scattering occurs;
- and
- calculating a ratio of the change amount for each of the propagation modes as the group delay ratio between the modes.
An optical fiber testing device for evaluating a group delay ratio between modes of an optical fiber to be measured, the device comprising:
- a measuring instrument for measuring a change amount of wave number in a Brillouin Frequency Shift for each two propagation modes having the same acoustic mode excited when stimulated Brillouin scattering occurs;
- and
- a calculator for calculating a ratio of the change amount for each of the propagation modes as the group delay ratio between the modes.
Dependencies are inferred from the claim text.