LASER DRIVER CONTROL CIRCUIT

摘要

A dual loop laser control circuit using a single preset resistor and a photo diode to control a laser diode (together with the photo diode forming a laser submodule). The coupling coefficient of the laser submodule is used to determine the value of the pre-set resistor prior to circuit assembly. Subsequent trimming of the pre-set resistor is not required as the circuit automatically adjusts for changes in laser efficiency and laser threshold. A data pattern from the input data is utilised in the feedback loops and compared to a data pattern received by the photodiode, thus avoiding data pattern sensitivities. This circuit can be integrated onto a single integrated circuit.