Ten-user truly asynchronous gigabit OCDMA transmission experiment with a 511-chip SSFBG en/decoder

Abstract

A ten-user truly asynchronous gigabit coherentoptical-code-division-multiple-access (OCDMA) transmission was experimentally demonstrated without using any timing coordination. The enabling technologies are a record-length 511-chip superstructured-fiber-Bragg-grating (SSFBG) en/decoder and a supercontinuum (SC)-based optical-thresholding technique to significantly suppress the signal interference beat noise as well as the multiple-access-interference (MAI) noise.

Spectral phase OCDMA encoder/decoder using travelling interference fringe photo-writing technique

“…Bi eff i v n f 2 (2) The effective index of the fiber n eff = 1.447 is calculated for standard telecommunication fiber SMF 28. v is the moving speed of the fiber.…”

“…Therefore, the OCDMA technique is considered today as an attractive solution for next generation optical broadband services such as FTTH technology. It allows numerous signals from different users to share the same transmission medium, optimizing the use of the wide available bandwidth and offers an all optical encoding/decoding processing using optical devices with asynchronous access capability [1][2][3].…”

Demonstration of 1 Gb/s$\,\times \,$15-User CDM Over WDM-PON Using Electrical Spatial Coding and Subcarrier Multiplexing

“…Various PON solutions have been proposed so far, among which optical code division multiple access (OCDMA) [1] is considered as one of the attractive access technologies due to its advantages including high capacity, flexible network management, and the potential of security enhancement for the physical layer, etc. Several all-optical en/decoders have been used in OCDMA systems [2]- [4], which can offer chip rates as high as 640 Gchip/s [3]. However, OCDMA systems based on all-optical en/decoders suffer from severe beat noise and multiple access interference (MAI).…”

A Novel OCDMA Thresholder Based on Nonlinear Polarization Rotation

“…An alternative choice is the optical thresholder, which allows asynchronous operation. Different technologies, including nonlinear gain and phase changes in semiconductor optical amplifier (SOA), second harmonic generation (SHG) in periodically poled lithium niobate (PPLN) [3] and super continuing (SC) generation in dispersionflattened fiber (DFF) [4], have been used for optical thresholding.…”