Comparison on the sensitivity of fiber optic SONET OC-48 PIN-TIA receivers measured by using synchronous modulation intermixing technique and bit-error-rate tester

The sensitivity of SONET p-i-n photodiode receivers with transimpedance amplifier (PIN-TIA) from OC-3 to OC-48 data rates measured by using a standard bit-error-rate tester (BERT) and a novel synchronous-modulation inter-mixing (SMIM) technique are compared. A threshold inter-mixed voltage of below 15.8 mV obtained by SMIM method corresponding to the sensitivity of PIN-TIA receiver beyond -32 dBm determined by BERT for the SONET OC-48 PIN-TIA receivers with a required BER of better than 10-10 is reported. the analysis interprets that the inter-mixed voltage for improving the PIN-TIA receiver sensitivity from -31 dBm to -33 dBm has to be increased from 12.5 mV to 20.4 mV. As compared to the BERT, the SMIM is a relatively simplified and low-cost technique for on-line mass-production diagnostics for measureing the sensitivity and evaluationg the BER performances of PIN-TIA receivers.