Planar Optical Slabs for Rapid Laser Beam Divergence Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser communication systems face challenges in precisely and rapidly changing the divergence of laser beams, especially in maintaining pointing precision and stability, particularly due to temperature variations and mechanical instabilities, which affect alignment and communication efficiency.
Innovation Solution
The method involves using planar optical slabs of different thicknesses inserted between fixed, powered optical lenses to vary the beam divergence without altering the physical path length, allowing for rapid and precise changes in beam divergence while maintaining boresight direction stability, and incorporating an athermal configuration to compensate for thermal effects across varying temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional methods (moving/rotating lenses or mirrors) are used to change beam divergence, then beam divergence can be adjusted, but pointing precision and stability deteriorate due to mechanical movements and temperature variations
Solution Approach 1:
The patent replaces mechanical movement of lenses or mirrors with insertion of planar optical slabs of different thicknesses into the beam path. This substitution eliminates mechanical movements that cause pointing errors and instability, while still achieving beam divergence adjustment through the optical path length modification introduced by the slabs.
Solution Approach 2:
The patent introduces planar optical slabs as intermediary elements between the laser source and the beam delivery system. These slabs modify the optical path length and thus the beam divergence without requiring movement of the laser source or final optics, serving as a stable mediator that achieves divergence control without mechanical instability.
2Productivity
If rapid changes in beam divergence are achieved by moving components, then adaptability improves, but mechanical stability and alignment consistency worsen
Solution Approach 1:
The patent replaces mechanical movement with a selection mechanism that inserts pre-positioned optical slabs of different thicknesses. This allows rapid switching between divergence states by simply selecting different slabs rather than mechanically adjusting components, thereby achieving fast divergence changes without compromising alignment stability.
Solution Approach 2:
The patent pre-positions multiple optical slabs of different thicknesses in the optical path before operation. This preliminary arrangement allows the system to rapidly switch between divergence states by selecting from pre-configured options, eliminating the need for real-time mechanical adjustment and thus maintaining alignment stability while achieving rapid adaptability.
3Device complexity
If temperature variations are not compensated, then device complexity is reduced, but beam pointing stability and divergence consistency worsen
Solution Approach 1:
The patent selects optical slab materials with specific thermal expansion coefficients and refractive index temperature dependencies to compensate for temperature variations. By carefully choosing materials whose optical parameters change with temperature in a compensating manner, the system maintains beam pointing stability and divergence consistency without requiring active thermal compensation mechanisms.
Solution Approach 2:
The patent utilizes controlled thermal expansion of the optical slab materials to counteract temperature-induced changes in the optical system. The optical slabs are selected and positioned such that their thermal expansion and refractive index changes compensate for the thermal effects in the rest of the system, maintaining optical stability across temperature variations without additional active compensation.
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 enables precise and rapid adjustment of laser beam divergence, maintaining high pointing stability and consistency across temperature changes, thereby enhancing the efficiency and reliability of laser communication systems.
Implementation Method 1
planar optical slabs of different thicknesses inserted between fixed, powered optical lenses to vary the beam divergence without altering the physical path length
Implementation Method 2
incorporating an athermal configuration to compensate for thermal effects across varying temperatures
Data Source
AI summary
An optical system including a first lens element having an optical center, a second lens element having an optical center spaced apart from the first lens element and oriented such that a beam passing through the optical center of said first lens element will also pass straight the optical center of the second lens element, the beam defining an optical path; andat least one planar, optical slab configured to be movable between at least two positions, a first position wherein at least a portion of a planar surface of the optical slab is disposed between the first and second lens elements such that a beam transmitted therethrough also passes through the planar, optical slab and a second position wherein the planar, optical slab is fully outside of the optical path created by the first and second lens elements.