Abstract: A system and apparatus includes an optical masking unit that is configured for applying a user's mask code. The mask code has a code length of at least equal to a number of users. A light source unit is coupled to the optical masking unit. The light source unit includes a number of coherent lasers. The number of coherent lasers is at least equal to half the number of users. Each of the coherent lasers is configured for operation at a different specific prescribed operating frequency. A modulation unit is configured for applying the user's data to the coherent lasers. An optical combiner unit is operable for combining outputs of the coherent lasers to an optical fiber input.

Abstract: An optical fiber communications system using spread spectrum code division multiple access techniques to achieve better bandwidth utilization. A transmitting user in the system encodes the optical signal using a first coding mask, and a receiving user decodes the received signal using two decoding masks, all of the masks having lengths N. The first mask is divided into two sections of lengths N/2 each, one of the sections defining a first sub-code of length N/2, while the other section blocks light. Each of the second and third masks is also divided into two sections, which correspond to the two sections of the first mask. The section of the second mask corresponding to the coded section of the first mask has a second code that is identical to the first code, and the section of the second mask corresponding to the blocked section of the first mask is also blocked.

Abstract: Methods and apparati for spatially encoding and decoding spread spectrum communication signals using broad band light sources are disclosed. The encoding algorithms involve the use of orthogonal spatial wavelets, which are preferably discrete attenuation functions of light from different sources so that the discrete attenuation function is imposed upon the spectrum of the light source. The function may be used either merely for providing an encoded channel or by providing a second mask that may be, for example, the complement of the discrete attenuation function so that the light beam is discrete with the first attenuation function.