Verfahren und Vorrichtung zur Verbesserung der Freigabereaktion einer Laserdiode in einem optischen Übertragungssystem.

摘要

An apparatus 10 controls the enable response time of a laser diode 12 during the reception of a data signal. The laser diode 12 is powered by the combined outputs from a pulse and bias current supply 14, 16. The pulse current supply 14 is connected to an external controller (not shown), which provides serial pulses of data. The pulse current supply 14 converts the serial pulses of data to a series of current pulses that drive the laser diode 12 between high and low optical output intensity. The bias current supply 16 provides a DC offset to the pulse output of the pulse current supply 14. Further, the apparatus 10 controls the level of the DC offset to maintain the minimum optical output intensity of the laser diode 12 at a preselected desired level. The apparatus 10 constitutes a closed-loop, bias-current-supply controller 20, which employs a feedback path for monitoring the optical output intensity of the laser diode 12 and controlling the optical output intensity to a preselected value. To accomplish stable operation but permit rapid response to an enable signal, the closed-loop, bias-current-supply controller 20 has a first preselected response characteristic for a first preselected period of time in response to receiving the enable signal and a second preselected response characteristic thereafter.