title: Sub-cycle QAM modulation for VCSEL-based optical fiber links.
abstract: QAM modulation utilizing subcarrier frequency lower than the symbol rate is both theoretically and experimentally investigated. High spectral efficiency and concentration of power in low frequencies make sub-cycle QAM signals attractive for optical fiber links with direct modulated light sources. Real-time generated 10-Gbps 4-level QAM signal in a 7.5-GHz bandwidth utilizing subcarrier frequency at a half symbol rate was successfully transmitted over 20-km SMF using an un-cooled 1.5-µm VCSEL. Only 2.5-dB fiber transmission power penalty was observed with no equalization applied.
authors: DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, DK2800 Kgs. Lyngby, Denmark. ptit@fotonik.dtu.dk
authors: Tien-Thang
authors: TT
authors: Pham
authors: Roberto
authors: R
authors: Rodes
authors: Jesper Bevensee
authors: JB
authors: Jensen
authors: Connie J
authors: CJ
authors: Chang-Hasnain
authors: Idelfonso Tafur
authors: IT
authors: Monroy
mesh_terms: D003195:Computer Communication Networks / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*