Abstract

Part I of this two-part paper uses wave-optics simulations to look at the Monte Carlo averages associated with turbulence and steady-state thermal blooming (SSTB). The goal is to investigate turbulence thermal blooming interaction (TTBI). At wavelengths near 1 μm, TTBI increases the amount of constructive and destructive interference (i.e., scintillation) that results from high-power laser beam propagation through distributed-volume atmospheric aberrations. As a result, we use the spherical-wave Rytov number and the distortion number to gauge the strength of the simulated turbulence and SSTB. These parameters simplify greatly given propagation paths with constant atmospheric conditions. In addition, we use the log-amplitude variance and the branch-point density to quantify the effects of TTBI. These metrics result from a point-source beacon being backpropagated from the target plane to the source plane through the simulated turbulence and SSTB. Overall, the results show that the log-amplitude variance and branch-point density increase significantly due to TTBI. This outcome poses a major problem for beam-control systems that perform phase compensation.

Highlights

  • At wavelengths near 1 μm, the effects of turbulence are often more dominant than the effects of thermal blooming

  • This paper investigates turbulence thermal blooming interaction (TTBI) in the presence of turbulence and steady-state thermal blooming (SSTB). It does so via the Monte Carlo averages associated with the log-amplitude variance and the branch-point density. These metrics result from a point-source beacon being backpropagated from the target plane to the source plane through the simulated turbulence and SSTB

  • We quickly review the details associated with the split-step beam propagation method (BPM), spherical-wave Rytov number, SSTB, distortion number, and parameters of interest

Read more

Summary

Introduction

At wavelengths near 1 μm, the effects of turbulence are often more dominant than the effects of thermal blooming. Before moving on to the section, it is worth mentioning that this paper builds upon the preliminary analysis presented by Murphy and Spencer in a recent conference proceeding.[46] In particular, this paper reduces the overall trade space and uses computationally efficient steady-state simulations to clearly show an increase in both the log-amplitude variance and branch-point density due to TTBI. These results serve as a novel contribution to the atmospheric propagation research community

Setup for the Wave-Optics Simulations
Split-Step Beam Propagation Method
Spherical-Wave Rytov Number
Steady-State Thermal Blooming
Distortion Number
Parameters of Interest
Exploration Using the Wave-Optics Simulations
Number of Phase Screens Needed
Focused High-Power Laser Beam
Backpropagated Point-Source Beacon
Overall Trade Space
Results and Discussion
Conclusion
Full Text
Paper version not known

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