Abstract
The orbital angular momentum (OAM) of light can be another physical dimension that we exploit to make multiplexing in the spatial domain. The design of the OAM mode supporting fiber attracts many attentions in the field of the space division multiplexing (SDM) system. This paper reviews the recent progresses in photonic crystal fiber (PCF) supporting OAM modes, and summarizes why a PCF structure can be used to support stable OAM transmission modes. The emphasis is on the circular PCFs, which possess many excellent features of transmission performance, such as good-quality OAM modes, enough separation of the effective indices, low confinement loss, flat dispersion, a large effective area, and a low nonlinear coefficient. We also compare the transmission properties between the circular PCF and the ring core fiber, as well as the properties between the OAM EDFA based on circular PCF and the OAM EDFA based on the ring core fiber. At last, the challenges and prospects of OAM fibers based on the PCF structure are also discussed.
Highlights
The increase of transmission capacity is always the challenging and urgent task for optical fiber communications
We review the recent main achievements in designing orbital angular momentum (OAM) mode fibers based on photonic crystal fiber (PCF) structures
Based on five requirements for the design rules of OAM fibers for the stable transmission of OAM modes, we summarize the reasons why the PCF-based fibers can support OAM
Summary
The increase of transmission capacity is always the challenging and urgent task for optical fiber communications. Mode [4,5,6,7], which is composed of the even and odd modes of the same vector mode with nearly the same propagation constants The former MDM systems (using few-mode (6–12 modes) fibers) require large and a complex multi-input multi-output (MIMO) digital signal processing algorithm to cope with the strong mode coupling [8,9], while the latter MDM systems are considered to be MIMO-free systems because of the weak coupling between the orthogonal OAM modes [10,11,12,13]. The structure design of the OAM mode supporting fibers is currently a hot topic in the research of the OAM mode-based optical fiber communication system.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
