Laser Diode Current Driver With (1-t/T)^ Time Dependence in 0.35- \mu\text BiCMOS Technology for Quantum Random Number Generators

A laser diode current driver with (1-t/T) -1 time dependence in 0.35-μm BiCMOS technology is presented in this brief. It is intended for application in optical quantum random number generators. The current driver is based on the balanced type of a bipolar junction transistor translinear loop with a sawtooth current as one of its inputs. The controllability of the frequency, shape, amplitude, and dc level of the current pulses is provided. The achievable frequency bandwidth of the current pulses is up to 100 MHz. A relative error of the measured waveform at a frequency of 25 MHz is smaller than 3% in 97.4% of the time period of interest.