Micro-current and voltage detection based on metal-dielectric core-shell WGM microcavity

Measurement of low voltage and current is crucial in electronic integrated devices. However, there are certain challenges in directly measuring low voltage and current. Here, we propose a method of detecting micro-current by using laser resonance mode movement in a metal-dielectric core-shell whispering gallery mode (WGM) microcavity. The metal-dielectric core-shell hybrid microcavity is fabricated by using a simple brush-coating method, which has high stability and a low threshold of about 16.8 μJ/cm2. We have achieved electrically tunable WGM lasing by utilizing the thermo-optic effect in the hybrid microcavity. The laser resonant mode of the WGM microcavity can be tuned. The tuning rate is 9.9 nm/V for the lasing peaks. The results provide, to the best of our knowledge, a new strategy for detecting micro-current and voltage.