Application of low-power fiber optic demodulation technology based on VCSEL laser and wireless monitoring of coal mine roof

The report describes a VCSEL (Vertical Cavity Surface Emitting Laser) based on voltage and current wavelength modulation, along with a fiber grating demodulation technique using acetylene absorption peaks as a wavelength reference. This enables the laser to achieve a wavelength scanning range of 10.5nm, with the entire system operating normally within a temperature range of 0-40℃, and the effective wavelength scanning range of the laser being 4.5nm. Since temperature control is not applied to the laser, its operating temperature varies with ambient temperature changes, resulting in a system characterized by a wide demodulation range, low power consumption, and compact size. Additionally, the study explores self-organizing network technology based on LoRa(Long Range) wireless communication for fiber optic wireless demodulation hosts, relays, and sub-stations. Leveraging the low power consumption characteristics of the demodulation technique, this enables wireless transmission of signals.