a laser microphone

Abstract

The invention relates to the technical field of microphones, and provides a laser microphone, which includes a laser emitting unit, a laser beam splitting unit, a laser beam expanding unit, an optical sensor and a signal processing unit. The laser emitting unit emits the laser beam toward the laser beam splitting unit; the laser beam splitting unit divides the laser beam into a reference beam, and the unsplit laser beam enters the laser beam expanding unit; the laser beam expanding unit divides the unsplit laser beam The beam is expanded and collimated and incident on the optical sensor; when the optical sensor is affected by an external sound source, the incident laser beam is modulated, and the modulated laser beam returns along the incident direction, and forms a signal after passing through the laser beam expander unit and the laser beam splitter unit in turn. Light; the reference light and signal light are incident to the signal processing unit, and the signal processing unit performs photoelectric conversion and electrical signal processing on the reference light and signal light to form an electrical signal that can restore the sound of the sound source. The laser microphone of the invention has high sensitivity, strong anti-electromagnetic interference capability and can collect sound remotely and wirelessly.

Description

technical field [0001] The invention relates to the technical field of microphones, in particular to a laser microphone with laser signals as information carriers. Background technique [0002] Microphones have been widely used in various fields in daily life, such as conference venues, telephones, computers, intercom systems, etc. Traditional microphones mainly include dynamic microphones and condenser microphones. The signal pickup is based on the induction diaphragm vibrating with the sound wave and causing changes in the electric field or magnetic field to obtain a corresponding voltage output, which is used to restore the sound. The difference is that the working principle of the dynamic microphone is to use sound waves to push the diaphragm, and the diaphragm drives the coil to move, causing changes in the magnetic field lines, thereby generating a weak voltage; the working principle of the condenser microphone is to use sound waves to push the gold-plated diaphragm. ...

AI Technical Summary

Problems solved by technology

But now the microphone based on MEMS technology is still a capacitance modulation type. The vibration of the MEMS diaphragm is caused by the sound pressure, and the change of the capacitance value is caused by the vibration of the diaphragm. Compared with the traditional condenser microphone, the volume is only reduced, and the sensitivity is not obvious. improve

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