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Title: Experimental mitigation of the effects of the limited size aperture or misalignment by singular-value-decomposition-based beam orthogonalization in a free-space optical link using Laguerre–Gaussian modes

Limited-size receiver (Rx) apertures and transmitter–Rx (Tx–Rx) misalignments could induce power loss and modal crosstalk in a mode-multiplexed free-space link. We experimentally demonstrate the mitigation of these impairments in a 400 Gbit/s four-data-channel free-space optical link. To mitigate the above degradations, our approach of singular-value-decomposition-based (SVD-based) beam orthogonalization includes (1) measuring the transmission matrixHfor the link given a limited-size aperture or misalignment; (2) performing SVD on the transmission matrix to find theU,Σ<#comment/>, andVcomplex matrices; (3) transmitting each data channel on a beam that is a combination of Laguerre–Gaussian modes with complex weights according to theVmatrix; and (4) applying theUmatrix to the channel demultiplexer at the Rx. Compared with the case of transmitting each channel on a beam using a single mode, our experimental results when transmitting multi-mode beams show that (a) with a limited-size aperture, the power loss and crosstalk could be reduced by∼<#comment/>8and∼<#comment/>23dB, respectively; and (b) with misalignment, the power loss and crosstalk could be reduced by∼<#comment/>15and∼<#comment/>40dB, respectively.

 
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NSF-PAR ID:
10201636
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Optical Society of America
Date Published:
Journal Name:
Optics Letters
Volume:
45
Issue:
22
ISSN:
0146-9592; OPLEDP
Page Range / eLocation ID:
Article No. 6310
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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