Optical CDMA-based ATM switches supporting equal-bit-rate and variable-bit-rate communication services

This paper presents the design of new optical ATM switches that use code-division multiple access (CDMA) and strict optical orthogonal codes (OOC's). The cross-correlation and autocorrelation constraints (i.e. lambda(c) and lambda(a)) of strict OOC's are always limited to be "1" for incoherent optical processing, regardless of whether an aperiodic or a periodic pulse sequence is input to optical CDMA decoders. Since the coding and correlation of strict OOC's are performed in the optical domain, the processing speed of proposed ATM switches can be very high. This can support real-time broadband communications. Moreover, the proposed ATM switch can flexibly handle both equal-rate and variable-rate communication services without violating lambda(c) = lambda(a) = 1 and with no any change of optical CDMA encoders/decoders. In so doing, it can substantially improve the switch flexibility without increasing system complexity.