Systems and methods for biasing an externally modulated laser. An
inductorless bias T network is provided that includes a terminating
resistor in series with a capacitor. The capacitor is an open circuit for
a bias signal and a virtual ground for an RF signal. Thus, the RF signal
is terminated by the terminating resistor without dissipating the bias
signal through a ground return path of the RF signal. Using a charge pump
inverter, a positive supply can be used to positively bias a laser and
negatively bias the external modulator through the terminating resistor.
A negative power supply is not required. A swing voltage provided by the
RF signal causes the external modulator to modulate the light emitted by
the laser.