Digital Coherence Enhancement Enabling 6-GBd DP-64QAM Using a 1.4-MHz Linewidth Laser

Author

Lavery, Domanic ; Maher, Robert ; Paskov, Milen ; Thomsen, Benn C. ; Bayvel, Polina ; Savory, Seb J.

Author_Institution

Dept. of Electron. & Electr. Eng., Univ. Coll. London, London, UK

Volume

25

Issue

22

fYear

2013

fDate

Nov.15, 2013

Firstpage

2213

Lastpage

2216

Abstract

This letter demonstrates the possibility of using digital coherence enhancement-a means of estimating and digitally compensating local oscillator laser phase noise using a secondary, low speed coherent receiver-to enable the reception of high order quadrature amplitude modulation (QAM) using a monolithically integrated tunable semiconductor laser as local oscillator. We show that this coherence enhancement technique compensates both the Lorentzian and non-Lorentzian distributed phase noise of this laser, enabling reception of DP-64QAM without differential decoding, and with a record (linewidth)×(symbol duration) product of 2.3×10^-4.

Keywords

laser noise; laser tuning; light coherence; optical modulation; optical receivers; phase noise; quadrature amplitude modulation; semiconductor lasers; DP-64QAM; Lorentzian distributed phase noise; coherent receiver; digital coherence enhancement; digital compensation; frequency 1.4 MHz; high order quadrature amplitude modulation; laser phase noise; local oscillator laser; monolithically integrated tunable semiconductor laser; nonLorentzian distributed phase noise; symbol duration; Laser noise; Measurement by laser beam; Optical interferometry; Optical noise; Optical receivers; Phase noise; Coherent receivers; laser linewidth; optical communications; quadrature amplitude modulation (QAM);

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2013.2283744

Filename

6612652