Coherent Sources/Solid-state laser

The high-speed fiber Bragg grating (FBG) interrogator is designed to precisely demodulate the center wavelength of FBG sensors. Based on tunable semiconductor laser swept-frequency demodulation technology, the interrogator uses all-solid-state components with no moving parts internally, offering advantages such as low power consumption, excellent shock resistance, and high precision. The interrogator consists of a laser source, laser driver, return light receiver, and a main control unit. A constant-current driver and a temperature-control module drive the laser to emit a swept-frequency laser beam, which passes through optical components including a collimator, a circulator, and a coupler before entering the FBG sensor. The reflected light returns through the circulator and is converted from optical intensity signals into electrical signals by a photoelectric conversion module. The main control unit processes the intensity information of the return light at different frequencies and employs a peak-seeking algorithm to accurately demodulate the sensor's center wavelength.