The Development Of Synchronous Optical Signal Source For Rewritable All-optical Buffer

All-optical packet switching is an importent part of all-optical networks.All-optical buffer is one of the key devices in the all-optical switching node.All-optical buffer can store and transmit optical signals without O/E transformation,it can solve the conflict between several optical signals effectively.As a key component,all-optical buffer has the advantages of high speed of writing and reading,excellent buffer depth and high information capacity.We should improve the capability of all-optical buffer so that the technology of all-optical packet switching be developed.In order to make rewritable all-optical buffer work,a optical source is needed which can output accurate pump to make the signals be write in or read out from the buffer.What I have done is manufacturing three optical sources to ouput "write","read" and "clear" pumps for the rewritable all-optical buffer and insure the clock synchronization of three pumps.To develop the optical source of the buffer is a effective way to develop the all-optical buffer.What I have done are as follows:1.Three programmable direct-modulated optical sources are manufactured to ouput "write","read" and "clear" pump for the all-optical buffer.Welding,debugging,testing and enchasing are all completed.The temperature control current range from-700mA to700mA,the optical power output reachs10mW.2.A digital signal processing PCB based FPGA is welded to provide modulation signal for the three optical sources.A program is writed with Verilog HDL in ISE,which can decide the period,phase and duty cycle of modulation signal.3.A single quartz crystal oscillator is choosed to be the reference clock.After frequency multiplication,a program is writed to output three modulation signals which are synchronous.The simulation of clock synchronization between three signals is realized with ISE.4.Three optical signals are coupled to the O/E converter of oscilloscope with a3x1coupler so that we can observe them.Rewriting the program to change the period,phase and duty cycle of optical signals,a expected result is got.