Spatially Modulated Clearing Beam for Free-Space Optical Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing free-space optical communication systems face significant challenges due to atmospheric absorption, scattering, and turbulence, which limit the transmission of optical signals through obscurants like clouds, fog, rain, dust, and aerosols, leading to high propagation loss and requiring complex, costly, and energy-intensive solutions.
Innovation Solution
The development of a spatially and temporally modulated clearing channel light beam with regions of low and high intensity, utilizing wavelengths that attract or repel obscurant particles based on their optical properties, creating a clear channel for optical data transmission by using beams with properties such as Bessel or Laguerre-Gaussian profiles, which are collimated to maintain intensity profiles over specified distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to overcome extinction and turbulence by increasing power or aperture size, then transmission reliability is improved, but device complexity and cost increase
Solution Approach 1:
A clearing beam is introduced as an intermediary element that selectively interacts with obscurant particles. This beam acts as a mediator to remove particles from the transmission path, enabling reliable optical transmission without requiring increased power or aperture size of the main communication beam.
Solution Approach 2:
The patent replaces mechanical approaches (increasing aperture size, using multiple transmitters) with an optical field-based solution. The clearing beam uses optical radiation pressure and scattering forces to remove particles, substituting mechanical systems with an optical field interaction approach.
2Reliability
If hybrid systems combining optical and RF beams are used, then transmission reliability is improved, but device complexity and weight increase
Solution Approach 1:
The patent segments the optical beam into functional components: a clearing beam for particle removal and a data transmission beam for communication. This segmentation allows each beam to be optimized for its specific function, avoiding the need for complex hybrid RF/optical systems while maintaining reliability.
Solution Approach 2:
The clearing beam serves multiple functions: it removes particles, defines the transmission channel, and can be used to characterize atmospheric conditions. This multi-functionality reduces the need for separate systems, lowering overall device complexity compared to hybrid approaches.
3Reliability
If multiple transmitters or receivers are used for spatial diversity, then transmission reliability is improved, but device complexity and cost increase
Solution Approach 1:
The clearing beam acts as a shared intermediary resource that enables reliable transmission through a single transmitter-receiver pair by dynamically removing particles from the path. This eliminates the need for multiple transmitters or receivers while maintaining the reliability benefits of spatial diversity.
4Reliability
If RF/MW beams are used for wavelength diversity, then transmission reliability is improved, but data transmission rate decreases
Solution Approach 1:
The system dynamically switches between optical and clearing beam modes based on atmospheric conditions. When the optical channel is degraded, the clearing beam is activated to restore transmission, allowing the system to maintain high data rates by staying in optical mode most of the time while having the capability to switch when needed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces optical attenuation by clearing obscurants from the transmission path, enabling low-loss, compact, and cost-effective free-space optical communication systems capable of maintaining high data rates over extended distances without the need for extensive equipment or infrastructure.
Implementation Method 1
The clearing channel light beam is provided by one of the first or second locations. The clearing channel light beam shape is such that obscurant particles are attracted into the high intensity portions of the spatially modulated light beam, leaving low intensity portions of the clearing channel light beam clear of the obscurant particles.
Data Source
AI summary
A method and apparatus for clearing an optical channel for transmitting data through free space between a first and second location includes a light beam, wherein the light beam has a spatially and/or time-dependent modulated intensity profile, and is substantially collimated so that the intensity profile is conserved over a specified distance of operation. The light beam includes a cross-sectional profile having regions of low and high intensity, portions of which are provided for the transmission of an optical data signal. A light source wavelength and intensity are selected for types of obscurant particles having optical properties whereby the radiation pressure acts on the particles, and the particles may then be either attracted into or repelled from portions of the spatially modulated optical beam, leaving certain portions of the optical channel beam absent of obscurant particles, thereby enabling transmission of optical data through the cleared optical channel with low attenuation.