Constructions for (2×n,{2,2},1)-2D optical orthogonal codes

Optical orthogonal codes (OOCs) have been designed for OCDMA system. Most researches on 2D OOCs have concentrated on the codes with one-pulse per wavelength (OPPW) or at most one-pulse per wavelength (AM-OPPW). However, the OPPW or AM-OPPW 2D OOCs are so sparse that reduce the bandwidth utilization, so the more pulses per wavelength cases should be used. A family of two-dimensional optical orthogonal code (2×n,4,1)-2D OOCs with two-pulses per wavelength is proposed in this paper. A tight upper bound on the maximum possible code size and some direct constructions of almost optimal (2×n  ,{2,2},1)-2D OOCs with n=q,2q,3q,4qn=q,2q,3q,4q, where q is an odd prime, are given.