基于光子集成芯片的可穿戴光纤光栅解调研究

为了实现光纤光栅传感器在可穿戴系统中的应用,提出了一种基于硅基光子集成芯片的可穿戴光纤光栅传感解调系统。基于比利时iSiPP50G工艺的光子集成芯片由4×1长波长VCSEL阵列、1×8阵列波导光栅、2×2 MMI耦合器、4×1光纤光栅耦合器阵列、Ge-on-Si波导光电探测器、直波导和弯曲波导等组成。在完成对VCSEL光源金线键合和光子集成芯片光纤耦合封装的基础上,设计了手环式解调电路,对人体温度和心音信号进行了实时测量。实验结果表明:解调系统的动态波长检测范围为1 540 nm～1 560 nm,波长分辨率为0.08 pm,解调精度为5 pm,温度监测范围为35℃～42℃,误差为±0.1℃;可检测50 Hz～100 Hz频率范围内的心音信号,可识别出第一心音和第二心音,并计算出心动周期、心率、第一心音时限、第二心音时限和心力等特征参数。

Wearable fiber grating demodulation based on photonic integrated chip

In order to realize the application of fiber grating sensor in wearable system, a wearable fiber grating sensor demodulation system based on silicon-based photonic integrated chip was proposed. The photonic integrated chip based on Belgium iSiPP50G process was composed of 4×1 long wavelength VCSEL array, 1×8 array waveguide grating, 2×2 MMI coupler, 4×1 fiber grating coupler array, GE-on-SI waveguide photodetector, straight waveguide and curved waveguide, etc. After completing the gold wire bonding of the VCSEL light source and the optical fiber coupling package of the photonic integrated chip, a wristband demodulation circuit was designed to measure the human body temperature and heart sound signals in real time. The experimental results show that the dynamic wavelength detection range of the demodulation system is 1 540 nm~1 560 nm, the wavelength resolution is 0.08 pm, the demodulation accuracy is 5 pm, the temperature monitoring range is 35 ℃~42 ℃, and the error is ±0.1 ℃. It can detect the heart sound signal in the frequency range of 50 Hz~100 Hz, identify the first heart sound and the second heart sound, and calculate the cardiac cycle, heart rate, the first heart sound time limit, the second heart sound time limit and cardiac parameters.