Out-off wavelength measuring method for lp11 mode in optical fiber and measuring unit

Abstract

Abstract PURPOSE:To establish the LP11 mode cut-off measuring unit which can measure the true value with high accuracy, by cutting off LP01 mode with direct polarization for the incident light to measured optical fiber and measuring the intensity of LP11 mode. CONSTITUTION:The position of the chopper 3, polarizer 4 and lens 5 is set so that the wavelength variable light from the wave length variable light source 1 can be incident to the measured optical fiber 6. Next, the wavelength of the wavelength variable light source 1 is determined so that the mode propagating the measured optical fiber 6 can be single mode, and the direction of polarization of the polarizer 4 is taken as Y axis. The outgoing light of measured optical fiber 6 remains only LP01 mode and the direction of polarization of the detector 7 is taken as X axis, allowing to cut off LP01 mode. The optical detector 10 can measure the intensity of LP11 mode only. This method can substantially measure true value in comparison with the method using bending.

Inventors

• 👤 Yasuyuki Kato
• 👤 Kenichi Kitayama

Bibliographic Details