Operational stability of a spectrally encoded optical CDMA system using inexpensive transmitters without spectral control

We show that an 8/spl times/155.52 Mb/s optical code-division multiple-access system applying periodic spectral encoding can be operated with poor quality optical filters and only loosely specified optical sources while still achieving bit-error rates (BER)=10/sup -10/ for each transmitter in asynchronous operation. It is experimentally found that BER<10/sup -9/ is maintained, if the optical receiver filter periodicity is changed by up to /spl plusmn/0.27%. From this finding we deduce that the optical transmitter filters do not need to be actively temperature controlled within the range -40/spl deg/C to +85/spl deg/C. This robustness is qualitatively understood from a simple crosstalk model depicted in the letter.