We analyze a code-division multiple access technique where information
is optically encoded by manipulating the coherence between a pair of
transmitted signals. Key features are intrinsic security, operation of
the receiver at only the bit rate of a single channel, and reconfigur
ation without switching optical delays, which are considerable advanta
ges compared to previously proposed CDMA schemes. Experimental results
demonstrating the basic operation of the scheme are presented. The pe
rformance limitations are calculated and novel implementations are pro
posed.