Optical sensor digital demodulation device and method based on frequency sweep light source

Abstract

The invention discloses an optical sensor digital demodulation device and method based on a sweep frequency light source. The device comprises the sweep frequency light source, an optical sensor, a photoelectric detector, a comparator, a digital timer and a digital demodulation device which are connected in sequence. The sweep frequency light source outputs a first light signal; the optical sensor receives the first optical signal and outputs a second optical signal carrying sensing information; the photoelectric detector converts the second optical signal into a first electric signal and outputs the first electric signal; the comparator receives the first electric signal and outputs a second electric signal of a digital level; the digital timer receives the second electric signal and outputs a first digital signal; and the digital demodulation device receives the first digital signal, and demodulates the sensing information by analyzing the characteristics of the pulse width sequence in the first digital signal. The spectrum of the optical sensor is demodulated in a digital demodulation mode, the sensing signal data volume is reduced by several orders of magnitude, and the processing problem of time domain demodulation huge data is fundamentally solved.

Description

technical field [0001] The invention belongs to the technical field of signal demodulation, and in particular relates to an optical sensor digital demodulation device and method based on a frequency-sweeping light source. Background technique [0002] The use of optical technology can achieve higher sensitivity sensing of external environmental variables, and the change of external parameters can be obtained by demodulating the spectral response variation of the optical sensor. The demodulation of the optical sensor spectrum can generally be divided into two types: spectral domain demodulation and time domain demodulation. Spectral domain demodulation usually uses a spectrometer to directly measure the spectral change of the sensor device, but spectral domain demodulation has high cost, slow demodulation speed, and low resolution (the resolution of a common spectrometer is 0.02nm, that is, 2.5GHz resolution) And other shortcomings, which make it limited in practical applica...

AI Technical Summary

Problems solved by technology

Spectral domain demodulation usually uses a spectrometer to directly measure the spectral change of the sensor device, but spectral domain demodulation has high cost, slow demodulation speed, and low resolution (the resolution of a common spectrometer is 0.02nm, that is, 2.5GHz resolution) And other shortcomings, making it limited in practical applications (such as wearable health monitoring, portable safety engineering monitoring, etc.)

Another time-domain demodulation, based on frequency-time mapping technology, maps the spectrum to the time domain and then collects the sensing information through an analog-to-digital converter. It has the advantages of fast speed and small size. The disadvantage is that the hardware cost is not low, and the computing power High cost, difficult to use in wearable monitoring application scenarios

The reason for its high cost of computing power is that high-speed acquisition in the time domain will generate a huge amount of data in a short period of time. Ordinary low-power chips cannot meet the computing power requirements at all. Even a personal computer is not competent, and the computing power requires high It also directly brings about the problem of high power consumption, which is difficult to achieve in wearable applications

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