Study on the sensitivity-frequency response characteristics of DAS systems under prestrain control

【摘要】 Distributed acoustic sensing(DAS) operates by detecting the dynamic strain along the optical fiber.As a key factor,the initial prestrain applied to the fiber significantly influences DAS performance,yet its quantitative impact remains inadequately studied.This work established a quantitative relationship between prestrain and DAS performance metrics—specifically,amplitude-frequency response and sensitivity—through theoretical modeling and experimental validation.The results indicated that an optimal prestrain of approximately 1000 με yields peak sensitivity,achieving a 6.23 dB gain over the slack fiber condition.Furthermore,when prestrain exceeds this optimum,the fiber resonance frequency increases(at a rate of 0.48 Hz per 10~3 κε),while the amplitude response decays(with a coefficient of -2.83 dB per 10~3 με).These findings provide valuable guidance for optimizing DAS deployment and calibration in field monitoring applications.更多还原

【Abstract】 Distributed acoustic sensing(DAS) operates by detecting the dynamic strain along the optical fiber.As a key factor,the initial prestrain applied to the fiber significantly influences DAS performance,yet its quantitative impact remains inadequately studied.This work established a quantitative relationship between prestrain and DAS performance metrics—specifically,amplitude-frequency response and sensitivity—through theoretical modeling and experimental validation.The results indicated that an optimal prestrain of approximately 1000 με yields peak sensitivity,achieving a 6.23 dB gain over the slack fiber condition.Furthermore,when prestrain exceeds this optimum,the fiber resonance frequency increases(at a rate of 0.48 Hz per 10~3 κε),while the amplitude response decays(with a coefficient of -2.83 dB per 10~3 με).These findings provide valuable guidance for optimizing DAS deployment and calibration in field monitoring applications.更多还原