従来の光検出器は光の時間平均強度を測るもので，光の電場波形あるいは瞬時電場を計測するものではありません．本研究では，光電場による電子のトンネル放出を利用して，光の瞬時電場を高感度に検知するデバイスを開発しました．金属／誘電体界面を流れる電流を外部に取り出すことにより，赤外パルスの光電場の向きと大きさを検知できることを実証しました．瞬時電場の検知を全固体デバイスで実現した点に高い独自性があり，光電場波形を計測する全固体デバイスの基礎になる成果と言えます．
Conventional photodetectors measure the time-averaged intensity of light and do not measure the electric field waveform or instantaneous electric field of light. In this study, we have developed a device that can detect the instantaneous electric field of light with high sensitivity using tunneling emission of electrons due to the optical electric field. It is demonstrated that the direction and magnitude of the optical electric field of an infrared pulse can be detected by externally extracting the current flowing at the metal/dielectric interface. This is highly unique in that the instantaneous electric field detection was achieved using an all-solid-state device, and is an important achievement for all-solid-state devices that measure the waveform of the optical electric field.