This document discusses using code division multiple access (CDMA) technique for optical fiber transmission. It aims to take advantage of optical fiber's large bandwidth and use CDMA to allow multiple users to access the channel simultaneously with unique PN codes. The key points are: 1. CDMA uses digital coding instead of frequency or time division for multiple access, giving each user a unique pseudorandom noise (PN) code. 2. The system uses PN codes to spread user signals before combining them and transmitting over fiber. Receivers correlate with assigned PN codes to separate signals. 3. Experiments are designed to test low pass, band pass, and electrical-optical conversion circuits needed for the CD