Laser self-mixing multi-dimensional measuring device and method based on triangular wave current modulation

Abstract

The invention provides a laser self-mixing multi-dimensional measuring device and method based on triangular wave current modulation. The laser self-mixing multi-dimensional measuring device comprises a laser device, optical fibers, an optical fiber beam splitter, an optical fiber focuser, a photoelectric detector and a signal processing circuit. A laser self-mixing sensing system comprises a plurality of paths of different optical path structures with the triangular wave current modulation, and a band-pass filtering signal processing circuit; and the multi-dimensional speed size and direction can be accurately measured on line by virtue of the single laser device and the single detector. The laser self-mixing multi-dimensional measuring device provided by the invention has the advantages of simple structure, easiness in adjustment, low cost and high space resolution, effectively expands a speed sensing method based on a laser self-mixing effect, and particularly provides a reliable solution scheme for non-contact online monitoring on the three-dimensional motion speed of a long-distance object.

Description

technical field

[0001] The invention relates to a laser self-mixing multi-dimensional velocity measurement device and method based on triangular wave current modulation, which is especially suitable for rapid non-contact measurement of water flow velocity and solid particle movement velocity. Background technique

[0002] For complex multi-dimensional motion velocity measurement, laser Doppler velocimetry technology has been proved to be more effective at present. Laser Doppler velocimetry technology has the advantages of non-contact, fast response, and high spatial resolution. It is widely used in flow velocity measurement in many fields such as fluid mechanics, chemical industry, water conservancy, biomedicine, and environment, especially the measurement of three-dimensional flow velocity.

[0003] In the laser Doppler multi-dimensional velocity measurement technology, the system structure scheme of the reference beam type is mainly used. The Doppler frequency shifts in d...

Examples

Embodiment Construction

[0049] Such as figure 1 As shown, the measuring device of the present invention includes: a photodetector 1, a laser 2, a laser modulation module 3, a first optical fiber 4, an optical fiber beam splitter 5, a second optical fiber 6, a third optical fiber 7, a fourth optical fiber 8, a first Fiber focuser 9, second fiber focuser 10, third fiber focuser 11, moving object to be measured 12, differential amplification circuit 13, three-channel filter bank 14, three-channel counter bank 15, computer 16, the laser modulation Module 3 modulates the laser 2 with a triangular wave current. The optical path is divided into three beams by the fiber optic beam splitter and incident on the surface of the object 12 to be measured. Part of the scattered light from each path is fed back to the laser according to the original path to generate the laser self-mixing effect. The photodetector 1 will The self-mixing optical signal is converted into an electrical signal, and the Doppler frequency ...

technical field

[0001] The invention relates to a laser self-mixing multi-dimensional velocity measurement device and method based on triangular wave current modulation, which is especially suitable for rapid non-contact measurement of water flow velocity and solid particle movement velocity. Background technique

[0002] For complex multi-dimensional motion velocity measurement, laser Doppler velocimetry technology has been proved to be more effective at present. Laser Doppler velocimetry technology has the advantages of non-contact, fast response, and high spatial resolution. It is widely used in flow velocity measurement in many fields such as fluid mechanics, chemical industry, water conservancy, biomedicine, and environment, especially the measurement of three-dimensional flow velocity.

[0003] In the laser Doppler multi-dimensional velocity measurement technology, the system structure scheme of the reference beam type is mainly used. The Doppler frequency shifts in d...

Examples

Embodiment Construction

[0049] Such as figure 1 As shown, the measuring device of the present invention includes: a photodetector 1, a laser 2, a laser modulation module 3, a first optical fiber 4, an optical fiber beam splitter 5, a second optical fiber 6, a third optical fiber 7, a fourth optical fiber 8, a first Fiber focuser 9, second fiber focuser 10, third fiber focuser 11, moving object to be measured 12, differential amplification circuit 13, three-channel filter bank 14, three-channel counter bank 15, computer 16, the laser modulation Module 3 modulates the laser 2 with a triangular wave current. The optical path is divided into three beams by the fiber optic beam splitter and incident on the surface of the object 12 to be measured. Part of the scattered light from each path is fed back to the laser according to the original path to generate the laser self-mixing effect. The photodetector 1 will The self-mixing optical signal is converted into an electrical signal, and the Doppler frequency ...

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