Bessel Beam Generation via Ring Lens and Fourier Optics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for generating Bessel beams, such as using axicons or spatial light modulators, are inflexible, expensive, and prone to damage, with high losses during beam shaping, making them unsuitable for complex variants and high-performance applications.
Innovation Solution
A beam shaping arrangement using a ring lens and Fourier optics, where a beam pre-shaping element transforms the incident plane wave into a ring-shaped beam, which is then spatially Fourier transformed to produce a Bessel beam, allowing for flexible generation of Bessel beams with a high damage threshold and low losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If axicons are used as beam-shaping elements, then Bessel beams can be generated efficiently, but the device is inflexible, expensive, and prone to damage due to its central tip
Solution Approach 1:
The patent removes the problematic central tip structure from the beam-shaping element. By using a ring lens instead of an axicon, the design extracts the harmful central region that causes damage susceptibility while retaining the essential beam-shaping functionality through the annular aperture and Fourier optics configuration.
Solution Approach 2:
The ring lens configuration uses simpler, more robust optical components that are easier and cheaper to manufacture than axicons. The design trades the complex precision-tip structure of axicons for durable ring-shaped lenses that are less prone to damage and more cost-effective.
2Adaptability or versatility
If spatial light modulators are used to generate complex Bessel beam variants, then flexibility is improved, but the device becomes expensive with low damage threshold and high losses
Solution Approach 1:
The patent achieves flexibility by changing optical parameters (wavelength, ring radius, focal length) rather than using complex programmable devices. By adjusting the ring lens geometry and Fourier optics configuration, different Bessel beam variants can be generated with high efficiency and low losses.
3Loss of energy
If axicons are used for Bessel beam generation, then beam transformation efficiency is high, but manufacturing quality is difficult and cost is high
Solution Approach 1:
The ring lens design uses simpler manufacturing processes compared to axicons. The annular aperture and curved surface are easier to fabricate with standard optical manufacturing techniques, reducing both cost and manufacturing complexity while maintaining high transformation efficiency.
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 efficient, flexible, and robust generation of Bessel beams with low losses and a high damage threshold, suitable for high-performance applications, including material processing, microscopy, and optical tweezers, by avoiding complex and lossy structures.
Implementation Method 1
The Bessel beam is obtained by spatial Fourier transformation of such a ring. According to the invention, an annular lens is used to generate annular radiation.
Implementation Method 2
The annular lens generates a sharp annular beam profile in its focal plane.
Implementation Method 3
This is spatially Fourier-transformed by means of the Fourier optics arranged downstream of the annular lens in the beam path.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to an arrangement for generating a Bessel beam (5), comprising a beam shaping element (2) that transforms an incident beam (1) as a plane electromagnetic wave into a Bessel beam (5), wherein the beam shaping element (2) includes at least one annular lens (3, 3') and a Fourier optic, e.g. in the form of a Fourier lens (4). The invention proposes that a beam pre-shaping element (8) be provided upstream of the beam shaping element (2) in the beam path, which transforms the incident beam (0) into a beam (1) with an annular cross-section.