Propagation Characteristics of Hermite–Gaussian Beam under Pointing Error in Free Space

Abstract

Hermite–Gaussian (HG) beams have significant potential to improve the capacity of free-space optical communication (FSOC). The influence of pointing error on the propagation characteristics of an HG beam cannot be ignored in the FSOC system. Although the average irradiance of the HG beam under a small pointing error from the FSOC tracking mechanism has been investigated through Taylor series approximation, here, we propose that the average irradiance of the HG beam under an arbitrary magnitude pointing error can be deduced through a statistical averaging method. We firstly found that the average irradiance profile of an HG beam finally changes into an approximately Gaussian shape with the increase in pointing error and propagation distance and a larger beam waist at the transmitter could mitigate the profile change. The correlation coefficient between deduced theoretical expression and Monte Carlo simulation reaches 0.999. Additionally, the effective spot size, location of the local extreme value, average received power and signal-to-noise ratio (SNR) loss for an HG beam under pointing error were theoretically deduced and analyzed for the first time. We found that the effective spot size of the higher-order HG beam experiences less broadening under the pointing error than that of the lower-order HG beam. The fundamental theoretical expressions of average irradiance for an HG beam under pointing error have provided effective guidance for analyzing the propagation characteristics and link performance.

Opto-thermo-mechanical phenomena in satellite free-space optical communications: survey and challenges

“…The result of the transmitter pointing error in OAM multiplexed FSOC is discussed by Xie et al 108 and Li et al 109 In mode division multiplexed links, which makes use of other orthogonal beam modes (e.g., Hermite-Gaussian beams) to multiplex the signal, the transmitter pointing error can also be a potential source of crosstalk between the signals. 110…”

Weak measurement of the Goos–Hänchen shift for a Hermite–Gaussian laser beam

“…If the beam has circular or elliptical polarization, these beams can carry spin angular momentum even when they do not carry orbital angular momentum (OAM). Higher-order HG modes have interesting properties compared to the fundamental TEM 00 mode, such as multiple intensity lobes [2], self-acceleration [3], self-healing [4], etc. As a result, these modes are used in many different fields, including optical communication [5], optical manipulation [6], quantum entanglement [7], electron acceleration [3] and many others.…”