基于硅基双微环谐振腔的高灵敏度电流传感器

High-sensitivity photonic current sensor based on Si dual-ring resonator

提出并制作了基于硅(Si)基双微环谐振腔的高灵敏度电流传感器。所设计的Si基双微环谐振腔的输出功率对波导内传输TE模的有效折射率变化非常敏感,探测由有效折射率变化造成的输出功率改变可实现高灵敏度微弱电流传感。在设计的Si基微环上集成了具有较高加热效率的TiN电阻,当有电流通过该电阻时,电阻发热并改变波导内传输TE模的有效折射率,最终造成微环输出功率改变。通过光功率计检测不同输入电流下微环输出功率,即可实现对电流的测量。实验结果表明,制作的微环传感器在测试范围为0~6mA时,灵敏度高达1 575dBm/A,线性相关系数R2大于0.999。

In this paper, we propose and demonstrate a compact silicon photonic current sensor based on Si dual-ring resonator. The output power of the designed dual-ring resonator is highly sensitive to the effec- tive refractive index of the TE mode propagating in the ring. The dual-ring resonator is fabricated on sili- con-on insulator （SOD by the CMOS compatible process,and the TiN resistors with high heating effi- ciency are fabricated in the ring. The current flowing through the integrated resistive TiN heater pro- duces Joule＇s heat and changes the temperature, which results in the change of refractive index of the TE mode. Finally, the output power of the dual-ring resonator is changed. In low current, the output power of the dual-ring resonator has almost a linear dependence on the current flowing through the TiN heater. A photoelectric detector is used to measure the change of the output power under different input currents. Our experimental results show that the proposed sensor achieves a sensitivity of 1 575 μm/A and a good linearity （RZ〉O. 999 ） in the test range of 0--6 mAThe footprint of the sensor is 70 μm）〈 90 μm, which is quite compact for on-chip current sensing. Meanwhile, the proposed sensor can be applied in areas such as electronic pulse detection and integrated optoelectronic interconnects.