10 x 112Gb/s PDM-QPSK transmission over 5032 km in few-mode fibers

Abstract

Few-mode fibers (FMFs) are used for the first time to transmit over 5000 km. Ten WDM channels with 50GHz channel spacing at 112 Gb/s per channel using PDM-QPSK are launched into the fundamental mode of the FMFs by splicing single-mode fibers directly to the FMFs. Even though few-mode fibers can support an additional spatial mode LP(11) at 1550 nm, the signal remains in the fundamental mode and does not experience mode coupling throughout fiber transmission. After each span the signal is collected by a second single-mode fiber which is also spliced to the FMF. Span loss is compensated by single-mode EDFAs before it is launched to the next FMF span. The lack of mode coupling ensures that the signal does not suffer any impairments that may result from differential mode delay or excess loss. Therefore the FMFs used in this "single-mode operation" have the same bandwidth as single-mode fibers. Experimental results verified that FMFs have the significant advantage of large core size which reduces the nonlinear impairments suffered by the signal. It is shown that FMFs with an effective area of 130 μm(2), have an optimum launch power 2 dB higher compared to standard single-mode fibers and as a result a 1.1 dB improvement in the Q-factor is obtained after 3000 km.

Evaluating effectiveness of optical burst switching networks by analytical models using queuing principle M/M/w/w and simulation on OMNeT++.

“…Đặc biệt, với các kỹ thuật điều chế và xử lý tín hiệu quang tiên tiến như QPSK (Quadrature Hình 1.1. Nguyên lý hoạt động của mạng chuyển mạch burst quang Phase-Shift Keying), PDM-QPSK (Polarization Division Multiplexing -QPSK) cho phép nâng tốc độ truyền tải của mỗi kênh bước sóng lên đến 112 Gbit/s hoặc 448 Gbit/s qua khoảng cách truyền tải lớn [1,2,3,4]. Để khai thác một cách hiệu quả khoảng băng thông cực lớn trên các tuyến truyền dẫn DWDM thế hệ mới, kỹ thuật chuyển mạch burst quang (OBS -Optical Burst Switching) [5] đang được nghiên cứu rộng rãi trên thế giới nhằm tìm ra các giao thức điều khiển tối ưu cho việc truyền lưu lượng IP qua mạng quang DWDM.…”

Design of a mode-field converter based on a two-core optical fiber with a long-period fiber grating

“…For example, it has been demonstrated experimentally that single-mode operation in a dual-mode fiber can be achieved simply by splicing single-mode fibers to both ends. [11][12][13] In this way, FMFs can be used for long-distance transmission without modal dispersion. Therefore, we can design FMFs with large mode areas to reduce the nonlinear effects.…”

“…[11][12][13] However, such a method induces large connection loss especially for large mode area FMFs, owing to the large differences in the mode-field area and distribution between SMFs and FMFs. In addition, such a method will also generate unwanted modes in FMFs, which is the cross talk to the fundamental mode.…”

Reception of Mode and Polarization Multiplexed 107-Gb/s CO-OFDM Signal over a Two-Mode Fiber

“…Tremendous progress has been made in high speed optical transmission utilizing polarization multiplexing, highorder constellation such as 16QAM and coherent optical detection, in both single carrier and OFDM formats [1] [2]. As fiber nonlinearity places a limit on achievable spectral efficiency [3], large effective-area (A eff ) single-mode fiber (SMF) or even multimode fiber (MMF) with selective launch of the fundamental (LP 01 ) mode have been investigated for reducing nonlinearity penalty [4], [5]. Information theory reveals that by adding another degree of freedom namely the spatial mode, the fiber capacity of MMF or few-mode fiber (FMF) can be increased in the form of multiple-input multiple-output (MIMO) transmission [6].…”