System for measuring half-wave voltage of phase modulator and measurement method

Abstract

The invention relates to a system for measuring half-wave voltage of a phase modulator and a measurement method. The measurement system comprises a laser generator, a polarization controller, a microwave signal generator, an optical interferometer, a power meter and a processor. The method comprises the following steps of: connecting a phase modulator to be measured into a detection system; determining working parameters of the system, and adjusting working conditions of the system; measuring optical power values under the condition of modulating microwave signals with different amplitudes, and comprehensively processing data; and measuring the half-wave voltage at different frequencies. By the system and the method, all the parameters measured at the same detection frequency are comprehensively processed by the characteristic of high resolution of modulation signals generated by the microwave signal generator to obtain a half-wave voltage value at the frequency, and the half-wave voltage value is circularly processed to obtain half-wave voltage values at various detection frequencies; and therefore, the system and the method have the characteristics that the system and the method are high in resolution of measurement frequency, the phase modulator has a plurality of measurement frequency points and a plurality of half-wave voltage measurement values and is high in accuracy, the using performance of a high-speed phase modulator can be exerted, the system and the method are systematical in measurement and low in measurement cost, and the like.

Description

technical field [0001] The invention belongs to a measurement system and a measurement method for half-wave voltage of a phase modulator in the fields of optoelectronic technology and microwave photonics, in particular to a measurement system and a measurement method for a high-speed phase modulator half-wave voltage. technical background [0002] Phase modulators are widely used in optical communication, microwave photonic filters, ROF and other fields. The basic principle of electro-optic phase modulator modulation is to use the electro-optic effect of crystals or anisotropic polymers, that is, by changing the applied voltage of crystals or anisotropic polymers to change their refractive index, thereby changing the phase of the passing light wave. The phase modulator has the advantages of simple structure, low insertion loss, and no need for external bias. The half-wave voltage is one of the most important parameters of the phase modulator, which characterizes the modulat...

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Problems solved by technology

[0006] However, the spectral analysis method is limited by the resolution of the existing spectral analyzer. The resolution of the spectral frequency in the spectral analysis method is generally about 1.25GHz (0.01nm). There are few frequency points to be measured, the interval between the measurable frequency points is large, and the measured value of the half-wave voltage obtained is small, resulting in the fact that the half-wave voltage of some frequency points that need to be measured cannot be directly measured through experiments, and can only be measured by adjacent The half-wave voltage at the measurable frequency point or the average value of the half-wave voltage at two adjacent frequency points is used instead. Therefore, this method has low resolution of the measurable frequency, poor adaptability and measurement accuracy, and it is difficult to ensure the use of high-speed phase modulators. The performance does not meet the requirements of practical applications, and the high cost of the measuring instruments used

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