Sub-Picosecond Time-Domain Measurement of Heterojunction Bipolar Transistors and Photodiodes

We demonstrate the time-domain measurement of the dynamic response of heterojunction bipolar transistors (HBT) and uni-travelling carrier photodiodes (UTC-PD) with sub-picosecond resolution. For the HBT, the stimulus is a step applied to the base. For the UTC-PD, we use optical excitation with 150 fs pulses at 1.55 mum. The detection of the electrical response is done using an electroabsorption sampling technique.