Patent ID: 6609842
Filing Date: 2003-08-26
Classification: H01S

Abstract:
A laser diode communication circuit, comprising:an input pulse communication signal; a laser diode having a back-facet photodiode for monitoring the output light signal from the laser diode; a current source coupled to the laser diode; a first operational amplifier having an input coupled to the input pulse communication signal and an output coupled to the current source for causing the current source to supply current to the laser diode in relation to the input pulse communication signal, wherein the laser diode and its back-facet photodiode are configured in a feedback loop between the output and the input of the first operational amplifier; and a spectral-shaping low-pass filter coupled between the input pulse communication signal and the input to the first operational amplifier, wherein the spectral-shaping low-pass filter creates a spectrally-shaped, bandwidth-limited input signal to the first operational amplifier that, when applied to the laser diode through the current source, provides a low-noise pulse communication optical signal from the laser diode.