Patent ID: 8521037

Claim:
A method for detecting a target pattern in a data stream, the method comprising: generating N delayed electrical data bitstreams from an electrical data bitstream having N bits, each of the N delayed electrical data bitstreams being delayed by an additional bit time as compared to the previous one of the N delayed electrical data bitstreams; superimposing the data bits from one of the N delayed electrical data bitstreams onto a first optical input bitstream to produce a pair of first-stage optical output bitstreams, the first one carrying the data bits from the one of the N delayed electrical data bitstreams and the second one carrying a complement of the data bits from the one of the N delayed electrical data bitstreams; comparing target bits from an electrical target bitstream having N bits with the data bits carried by the first one of the first-stage optical output bitstreams, and with a complement of the electrical data bit carried by the second one of the first-stage optical output bitstreams, to determine whether each of the target bits is same as each of the respective data bits; repeating the superimposing and the comparing with successive ones of the N delayed electrical bitstreams; and indicating a match when N of the target bits are determined by the comparing to be same.