An Arbitrary Waveform Optical Frequency Modulation and Source Tracing Device

Abstract

The invention discloses an arbitrary waveform optical frequency modulation and traceability device, which belongs to the technical field of photoelectric measurement. The present invention mainly consists of a laser vibrometer, a first λ / 2 wave plate, a second λ / 2 wave plate, a third λ / 2 wave plate, a fourth λ / 2 wave plate, a first polarizing beam splitter, a second polarizing beam splitter, third polarization beam splitter, fourth polarization beam splitter, beam splitter, first lens, second lens, first plane mirror, second plane mirror, third plane mirror, fourth plane mirror, It consists of the first acousto-optic modulator, the second acousto-optic modulator, FM signal source, arbitrary wave generator, sinusoidal signal source, photodetector, filter amplifier, digital oscilloscope, and electronic computer. Based on the technology of the arbitrary waveform optical frequency modulation device, the present invention realizes the precise demodulation of the modulated laser signal waveform in the optical frequency modulation device, obtains the demodulation result of its arbitrary waveform, and realizes the arbitrary waveform through the index parameters of the digital oscilloscope traceability.

Description

technical field [0001] The invention relates to an arbitrary waveform optical frequency modulation and source tracing device, which belongs to the technical field of photoelectric measurement. Background technique [0002] The laser vibrometer is a general-purpose, basic vibration and shock measuring instrument with high precision, non-contact, and no additional interference and influence on the measured object. Its measurement calibration and performance evaluation have always been difficult problems in the industry. The main reasons are: 1) Its excitation is the movement value (displacement, velocity, acceleration), and the measurement principle used is carried out through the laser Doppler effect, which needs to perceive physical movement through the change of optical frequency, and the output is based on electrical signal data The results are given in different forms, involving different aspects such as mechanical movement, optical frequency control, electronic measureme...

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Problems solved by technology

2) Since the frequency range and accuracy of photoelectric measurement are much higher than those of mechanical motion values, there has been a lack of suitable excitation sources for measurement calibration and performance evaluation, and it is difficult to find satisfactory ones. Devices and Equipment

Since the vibrating table is a physical movement device with an electromechanical structure, it is limited by the limitations of physical and mechanical principles, as well as the limitations of materials and machining capabilities. Compared with photoelectric measuring instruments such as laser vibrometers, its stability is not easy. It is very high, the frequency band is narrow, and the amplitude can reach a relatively large value at low frequencies, but at high frequencies, the amplitude can only achieve a very small value, and the accuracy is low, which is not easy to achieve for laser vibration measurement. Technical requirements for metrological traceability

Although standard laser vibrometers are used for metrological calibration, the uncertainty due to the characteristics of the shaking table and the limitations imposed by its amplitude and frequency range are still the main problems in the metrological calibration of laser vibrometers

4) On the other hand, the use of standard laser vibrometers to trace the source of other laser vibrometers also has a logical problem. The standard laser vibrometers’ own measurement and calibration problems still cannot be solved.

Due to the optical frequency modulation process, whether the arbitrary waveform used as a substantial stimulus maintains the technical characteristics of the original electronic signal waveform needs to be realized in the form of measurement and calibration, which leads to the traceability of the arbitrary waveform optical frequency modulation device

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