Half-Waveplate Beam Divergence Control Without Boresight Errors
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Solution Overview
Problem
Existing optical systems face challenges in controlling beam divergence without creating boresight or wavefront errors, which can occur when varying the distance between lenses, leading to undesirable line-of-sight and optical aberrations.
Innovation Solution
Utilizing a half waveplate in combination with birefringent lenses to control beam divergence by rotating or repositioning the waveplate, avoiding changes in lens spacing, thus eliminating boresight and wavefront errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the distance between lenses is varied to control beam divergence, then beam divergence control is achieved, but boresight errors and wavefront errors are created
Solution Approach 1:
The patent changes the polarization state of light using a half-wave plate rather than varying lens spacing. By rotating the half-wave plate, the polarization angle changes, which modifies the effective refractive index experienced by different polarization components in the birefringent lens, thereby controlling beam divergence without altering lens positions or introducing mechanical errors.
Solution Approach 2:
The patent replaces the mechanical system of varying lens spacing with an optical system using polarization control. Instead of mechanically moving lenses to control divergence, the system uses a rotating half-wave plate to control the polarization state, which then interacts with the birefringent lens to achieve divergence control without mechanical displacement errors.
2Adaptability or versatility
If lens spacing is adjusted to control beam divergence, then divergence adjustment is possible, but line-of-sight errors are introduced
Solution Approach 1:
The patent changes the polarization parameter of light using the half-wave plate rotation to control beam divergence. This parameter change affects the optical path difference between polarization components in the birefringent lens, enabling divergence adjustment without changing the physical positions of optical elements, thus maintaining line-of-sight accuracy.
3Adaptability or versatility
If lens distance is varied for beam shaping, then beam divergence control is achieved, but optical aberrations increase
Solution Approach 1:
The patent substitutes the mechanical adjustment of lens spacing with an optical polarization control mechanism. The half-wave plate rotates to change polarization states, which interact with the birefringent lens to control beam divergence without mechanical movement, thereby avoiding the introduction of wavefront aberrations that would result from lens displacement.
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
Achieves continuous or fixed beam divergence control without introducing boresight or wavefront errors, enhancing the precision and accuracy of optical systems.
Implementation Method 1
a half waveplate configured to alter a polarization of an input optical beam
Implementation Method 2
at least one of the lenses includes one or more birefringent materials
Data Source
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AI summary
A system includes an optical source configured to generate an input optical beam. The system also includes a half waveplate configured to alter a polarization of the input optical beam. The system further includes multiple lenses configured to reshape the input optical beam and generate an output optical beam, where at least one of the lenses includes one or more birefringent materials. A divergence of the output optical beam is based on the half waveplate and the at least one of the lenses including the one or more birefringent materials. In addition, the system includes an actuator configured to rotate or reposition the half waveplate in order to adjust the divergence of the output optical beam.