Terabit Optical Wireless-Fiber Communication With Kramer-Kronig Receiver—Part II

Abstract

A high speed optical wireless-fiber solution was proposed in part I of this research with applications such as network backhaul and data center links. The proposed system is based on the utilization of state-of-the-art modulation and multiplexing techniques in optical fiber and optical wireless communications, including multicore fibers (MCFs) and coherent detection based on Kramer-Kronig (KK) receivers. In this paper, we analyze the performance of the proposed system and compare it with an intensity modulation and direct detection (IM/DD) system. Superior performance of the KK receiver is shown for various modulation formats and optical amplification schemes. We also consider the eye-safety constraint for the optical power as a practical design factor. It is demonstrated that the position of optical amplifiers affects the multiplexing gain and achievable data rate when eye-safety constraint is imposed. Further important challenges for the practical deployment of the system are discussed.

Terabit Optical Wireless-Fiber Communication With Kramer-Kronig Receiver—Part I

“…The effect of the eye-safety power constraint is discussed in part II of this work, and it is observed that a higher number of wavelengths can be used for WDM with optical amplification at Rx. Therefore, amplification at Rx results in a higher overall data rate for the full WDM system [17].…”

“…In this paper, it is assumed that the link is terminated at the transmitter (Tx) and receiver (Rx) ends, however, the data modulation and detection units at the Tx and Rx can be replaced by optical switches in order to fit this link within a data center network or apply this design to other applications such as backhaul links. Part II of this work compares the system performance with intensity modulation and studies the eye-safety constraint [17].…”

100G FSO Transmission Using 3-Bit DAC and Self-Coherent Detection

“…Following this need, we have recently demonstrated 200 Gbps FSO transmission using a Kramers-Kronig (KK) self-coherent receiver [5], which allows replacing the full coherent receiver by a single photodiode, while still being compatible with phasepreserving receiver-side processing and advanced modulation, such as probabilistic constellation shaping (PCS) [6]. Noteworthy, this simplified coherent FSO architecture has attracted significant attention, being subject of several recent studies on achievable capacity [7,8].…”