Burst mode optical transmitters for BPON and GPON access networks

Burst-mode laser driver in 0.35 μm digital CMOS * with dummy metal layer Every ONU receives the same downstream information and selects the data that is addressed to it. Via downstream messages every ONU also finds the timeslots during which it is allowed to send upstream data, so that upstream bursts do not collide when they are combined on the single optical fiber towards the OLT. By consequence only one upstream transmitter is allowed to send data at a time. That is why burst mode transmitters are needed instead of continuous mode transmitters.