All optical fiber frequency domain interference absolute distance measurement method and device

Abstract

The invention relates to an accurate absolute distance measurement system, in particular to an all optical fiber frequency domain interference absolute distance measurement method and device and aims to solve the problems of the prior art. The device is convenient and easy to operate and is capable of measuring the absolute distance between a reflector surface and an optical fiber probe light emitting end face, the measurement accuracy is above 10nm, and the measurement distance can be 100cm. The device comprises a broadband light source, an array optical fiber filter, an optical fiber circulator, an optical fiber probe, an adjustable optical fiber filter and the like. The broadband light source, the array optical fiber filter and a first end of the optical fiber circulator are connected sequentially, a second end of the optical fiber circulator is connected to the optical fiber probe, the optical fiber probe emits the optical wave to the reflector surface and receives the reflected optical wave from the reflector surface, and a third end of the optical fiber circulator, the adjustable optical fiber filter, an optical fiber amplifier, an optical fiber spectrometer and a computer are connected sequentially.

Description

technical field [0001] The invention relates to an absolute distance precision measurement system, in particular to an all-fiber frequency-domain interference absolute distance measurement method and device with micro-nano resolution capability. Background technique [0002] As the first basic physical quantity in physics, distance (or length) has a wide range of uses in the fields of scientific and technological research, engineering applications, and instrument manufacturing. The measurement of distance involves a wide range of areas. Among them, precision distance measurement involves precision measurement. With microelectromechanical systems, etc., many physical quantities, such as acceleration, pressure and stress, can be detected indirectly by measuring distance and its changes. At present, inductive, grating, eddy current and scanning sensors are usually used for precision distance measurement. Inductive sensors have non-sliding contacts. Although they are not affect...

AI Technical Summary

Problems solved by technology

Inductive sensors have non-sliding contacts. Although they are not affected by non-metallic factors such as dust during operation, and have low power consumption and long life, the measurement object must be a metal conductor. In addition, because it is a contact measurement, it may affect the Negative impact on test subjects

Although the grating sensor has the advantages of easy digitization, strong anti-interference ability, no artificial reading error, convenient installation, and reliable use, etc., the measurement accuracy is generally at the micron level, and most grating sensors can only measure the distance generated during the movement of objects. Changing the value (i.e. displacement), cannot measure the absolute distance of the static object relative to a certain origin

The eddy current sensor uses the eddy current effect to measure the distance between the measured metal conductor and the probe surface statically and dynamically, with high linearity and high resolution, but the measured object must be a metal conductor, which limits its wide application.

Scanning sensors include wavelength scanning, time scanning and space scanning. Scanning displacement sensors are difficult to take into account the measurement accuracy and measurement range, and the system's anti-interference ability is poor. Typical wavelength scanning displacement sensor, its measurement accuracy can reach nanometers, but the measurement range is only a few millimeters

To sum up, the current precision distance measurement technology is difficult to take into account the distance measurement accuracy and measurement range, and it is difficult to meet the growing requirements of precision measurement and micro-electromechanical systems.

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