Apparatus and method for measuring polarization-dependent loss using repeated high speed polarization scrambling

Abstract

Disclosed is an apparatus and method for measuring a changing amount of insertion loss of an optical device depending on a polarization state of an incident light, i.e., a polarization-dependent loss. An incident light that is periodically subject to all polarization states passes through a testing optical device by a polarization scrambler including a piezoelectric element type optical fiber birefringence modulator, and an optical detector measures intensity of the passing light, in which the measured intensity values are averaged for birefringence modulation having a constant period, and then the polarization-dependent loss is computed from a ratio of maximum power to minimum power for the period. Use of the birefringence modulator shortens measuring time, and decreases an affect of external disturbance to the incident light that is incident into the testing optical component or occurrence probability of the external disturbance, so that the polarization-dependent loss can be precisely measured.

Description

field of invention [0001] The present invention relates to a device and method for measuring the variation of the insertion loss of an optical device, which loss depends on the polarization state of incident light, ie polarization-dependent loss. Background technique [0002] Due to the rapid development of optical communication technology, various optical components have been developed. In order to effectively manage the quality of optical components, the optical communication industry requires optical measurement instruments with high reliability and high measurement speed. In particular, since the introduction of the wavelength division multiplexing (WDM) transmission method has increased the necessity of measuring the characteristics of optical equipment corresponding to various wavelengths in a wide wavelength range, the demand for optical measuring instruments with high measurement speed has also increased. meet this requirement. [0003] Among various specifications...

AI Technical Summary

Problems solved by technology

However, the implementation of this method has the following limitations: the unavoidable calibration process when determining the ratio of the incident and output optical signal intensities of the DUT in the four polarization states, and the requirement that the four polarization states must be accurately obtained after inputting the same signal. Measurement procedure for the composite value of the polarization state

To achieve this, the input polarization state must be free from disturbances, however, if the measurement process is operated for too long, there is the problem that disturbances inevitably appear in the input polarization state

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