<title>Trade-off between IM-DD and coherent system in high-data-rate optical interorbit links</title>

Abstract

Trade-off between Intensity Modulation Direct Detection (IM-DD) and coherent system oriented to the inter-orbit lightwave communication link is performed. Improvement in sensitivity of IM-DD system adopting high power optical fiber booster/pre-amplifiers is discussed preciously. In this paper, IM-DD system with booster/pre-amplifier and five kinds of coherent system (ASK-heterodyne, FSK-heterodyne, PSK-heterodyne, DPSK-heterodyne, and PSK-homodyne) are compared for high-data rate communication. Numerical analysis shows the superior characteristics of coherent communication system in low BER transmission under severe ASE noise.

Performance Optimization of Optically Preamplified Receivers for Return-to-zero and Non Return-to-zero Coding

“…30 ppb) at 10 Gbit/s for differential phase-shift keying (DPSK) [14]. These values outperform all comparable results achieved by coherent reception so far, and thus make optically preamplified receivers a serious contender to coherent receivers for free-space optical communication systems [15,16]. An analysis of commercial availability of components, as well as on their robustness, mass, size, and cost, further emphasizes the superiority of optically preamplified receivers for space-borne communication links [17,18], especially when using the return-to-zero (RZ) data format rather than the more conventional non return-to-zero (NRZ) format.…”