Measurement of real-time digital signals in a silicon bipolar junction transistor using a noninvasive optical probe

Abstract

We report optical charge sensing of real-time 0.8 V digital signals in a silicon bipolar transistor in a 20 MHz bandwidth using a 1.3 μm semiconductor laser, and in a 100 MHz bandwidth using a 1.3 μm Nd:YAG laser. The probe is noninvasive, inducing a transistor base current of less than 10 nA.