Analytical Investigation on Self-Homodyne Coherent System Based on Few-Mode Fiber

Author

Zhen Qu ; Songnian Fu ; Minming Zhang ; Ming Tang ; Shum, Ping ; Deming Liu

Author_Institution

Next Generation Internet Access Nat. Eng. Lab., Huazhong Univ. of Sci. & Technol., Wuhan, China

Volume

26

Issue

1

fYear

2014

fDate

Jan.1, 2014

Firstpage

74

Lastpage

77

Abstract

We present an analytical investigation on the amplified spontaneous emission-limited self-homodyne coherent system based on a few-mode fiber. We test the accuracy of our model in the context of 112 Gb/s polarization-multiplexed quadrature phase-shift keying (QPSK) transmission through this system. We find that the application of dc offset elimination is necessary to reduce distortion of QPSK constellation. Meanwhile, a closed-form analytical bit error ratio (BER) formula is verified by numerical simulations with deviation at BER=10^-3, whereas the predicted optimum power ratio between data signal and pilot-tone signal agrees well with the simulation result. In addition, the adaptive equalization using modified constant modulus algorithm is shown effectively for the proposed system. The tolerance of residual time delay is ±18 ns after carrier phase alignment using optical delay line, given 0.5 dB optical signal-to-noise ratio penalty at BER=10^-3.

Keywords

adaptive equalisers; error statistics; numerical analysis; optical delay lines; optical fibre communication; optical fibre polarisation; optical fibre testing; optical noise; quadrature phase shift keying; superradiance; BER; QPSK constellation; adaptive equalization; amplified spontaneous emission-limited self-homodyne coherent system; bit rate 112 Gbit/s; carrier phase alignment; closed-form analytical bit error ratio formula; data signal; dc offset elimination; few-mode fiber; modified constant modulus algorithm; numerical simulations; optical delay line; optical signal-to-noise ratio penalty; pilot-tone signal; polarization-multiplexed quadrature phase-shift keying transmission; residual time delay tolerance; Optical fiber polarization; Optical filters; Optical noise; Optical polarization; Signal to noise ratio; Few-mode fiber (FMF); optical signal-to-noise ratio (OSNR); polarization-multiplexed quadrature phase-shift keying (PM-QPSK); self-homodyne (SH);

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2013.2288332

Filename

6655941