Phase modulator performance parameter testing device based on beam coherent combination

Abstract

The invention discloses a phase modulator performance parameter testing device based on beam coherent combination. The phase modulator performance parameter testing device comprises a laser (1), a 1*2 optical beam splitter (2), a first optical fiber, a second optical fiber, a third optical fiber and a fourth optical fiber, a phase modular (4), a first optical collimator, a second optical collimator, a beam combining lens (6), a beam splitter prism (7), a first microobjective, a second microobjective, a digital camera (9), a pinhole (10), a photoelectric detector (11), a frequency response tester (12) and a computer (13). The phase modulator performance parameter testing device simplifies measurement of phase modulator performance parameters and can measure all phase modulators with optical fiber interfaces. Simultaneously, the device can roughly estimate and accurately measure resonant frequency. When accuracy requirements are not high, the digital camera is used for observing far field speckle contrast to obtain the resonant frequency simply and rapidly; and when the accuracy requirements are high, accurate resonant frequency is obtained through analysis and calculation of signals acquired by the photoelectric detector.

Description

Technical field [0001] The invention relates to the field of optical instruments and measurement, in particular to a device and method for testing performance parameters of a phase modulator, in particular to a device and method for testing the phase shift coefficient and resonance frequency of the phase modulator. Background technique [0002] Phase modulators have a wide range of applications in beam coherent combination, optical communication, optical sensing and other fields. In the field of beam coherent synthesis, the phase modulator is the core component of the synthesis system. A certain control algorithm is used to control the phase modulator to compensate for the phase difference between the beams, so that the phases of two or more lights are consistent; in the field of coherent optical communication , The phase modulator can be used to load the signal to be transmitted on the carrier to complete the signal transmission; in the field of optical sensing, the phase modula...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention: Aiming at the problem that the phase shift coefficient and resonance frequency of the phase modulator cannot be well solved in the prior art, according to the active coherent synthesis structure, the far-field spot is introduced along with the phase modulator According to the characteristics and theoretical derivation of optical path difference, a test device and method that can measure the phase shift coefficient and resonance frequency of the phase modulator at the same time are proposed, and the test device can accurately obtain the phase shift coefficient of the phase modulator, and at the same time Can roughly estimate the resonant frequency of the phase modulator and can accurately measure the resonant frequency of the phase modulator

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