【摘要】 传统的利用光纤Bragg光栅(FBG)反射光作为长周期光纤光栅(LPFG)入射光的解调方式,无法避免温度的影响。本文提出了一种具有温度补偿功能的LPFG功率解调方案,将FBG的Bragg波长由压电陶瓷(PZT)的驱动电压控制,使得FBG谐振波长始终跟随LPFG谐振波长,以此抵消温度对传统功率解调中的影响。这种解调方案适用于LPFG透射光谱随物理量变化谱形也发生变化的传感,如微弯、横向负载等特性。利用本系统对LPFG的横向负载特性进行试验,结果表明,采用此解调方案获得的实验数据具有与光谱仪相同的功率变化趋势,能够始终监测LPFG的谐振峰幅值,实现温度补偿的功率解调,更适合于动态解调。对LPFG的温度特性进行功率解调实验,结果也验证了解调系统具有温度补偿功能。更多还原

【Abstract】 The traditional power demodulation method uses fiber Bragg grating(FBG) reflected light as the long period fiber grating(LPFG) incident light,which is unable to avoid the influence of the temperature.This paper puts forward a kind of power demodulation scheme which could compensate the environment temperature of the LPFG,and the Bragg wavelength will be controlled by PZT driving voltage,making the FBG resonance wavelength always follow LPFG transmission resonance wavelength,which could counteract the influence of the temperature.This demodulation scheme is suitable for physical quantity measurement,in which the LPFG transmission spectrum shape changes,such as micro bending,lateral load characteristics.From the LPFG transverse load characteristic test by this system,the results show that it has the same trend with optical spectrometer analyzer,it can always monitor LPFG resonant peak amplitude and realize the power demodulation with temperature compensation,and the method is more suitable for dynamic demodulation.From the temperature characteristics of LPFG power demodulation experiments,it is verified that the demodulation system has the function of temperature compensation.更多还原