It is very critical to improve the tracking stability in inter-satellites optical communication. The definition of the far-field light correlation efficient as been proposed, and the mathematical model that between it and divergence angle of tracking beacon has been established due to correlation of bidirectional beams. The results showed that the light intensity in the far-field is decreasing and dispersing with an increasing divergence angle, but not has an increasing far-field light correlation.
We review space-division multiplexing passive optical networks (SDM-PONs) based on multi-core fibers (MCFs) and few-mode fibers (FMFs). We compare and analyze the characteristics in terms of MCFs and FMFs used in PONs. A scheme of MCF based SDM-PON with colorless ONUs without any signal processing technology is demonstrated, thereby achieving a low cost and making the system design much easier.
In this paper, we compare and analyze some schemes of generating the optical frequency comb. We propose a flexible and low-cost broadband optical frequency comb for dense wavelength-division multiplexing passive optical network (DWDM-PON) system by using a CW laser and electro-optic modulators followed by a dispersion flattened high nonlinear fiber (DF-HNLF). The frequency spacing and center wavelength of the frequency comb can be flexibly adjusted by changing the radio-frequency signal and the output wavelength of a continuous-wave (CW) laser, respectively.