Voltage control of optical receiver bandwidth

An optical receiver is formed to include a digitally-controlled preamplifier that is used to adjust the bandwidth of the receiver. A measured bandwidth of the receiver is compared to a desired bandwidth and a digital control signal (such as a voltage, current, or any other appropriate parameter) supplied to the preamplifier is thereafter adjusted (either increased or decreased) to increase/decrease the bandwidth of the receiver to the desired value. A voltage regulator and potentiometer may be used as the digital controller and coupled to the input voltage supply of the preamplifier to provide the needed adjustment in voltage.