Optical Tweezers Spatial Light Modulator Phase Pattern
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Solution Overview
Problem
Conventional optical tweezers face a decrease in numerical aperture due to the division of the modulation surface, leading to a reduction in trapping force, making it difficult to maintain a strong object-trapping force over long distances.
Innovation Solution
The optical tweezers employ a spatial light modulator and phase pattern generating means to create multiple output beams with increased numerical aperture by arranging partial phase patterns two-dimensionally, allowing for independent movement of trapping positions and reducing diffraction noise through irregular array configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the modulation surface is divided into plural regions for independent phase patterns, then multiple objects can be trapped and moved individually, but the beam surface area decreases and numerical aperture reduces
Solution Approach 1:
The patent divides the modulation surface into multiple regions, with each region corresponding to a specific trapping position and containing its own independent phase pattern. This segmentation allows independent manipulation of multiple trapped objects while maintaining sufficient beam surface area in each region to preserve numerical aperture and trapping force.
2Force
If the beam is converged in a trapping position with sufficient numerical aperture, then strong trapping force is achieved, but the beam surface area is limited
Solution Approach 1:
The patent transitions from one-dimensional linear arrangement to two-dimensional arrangement of phase patterns on the modulation surface. This dimensional change allows multiple phase patterns to be packed more efficiently, increasing the number of simultaneously controllable trapping positions while maintaining adequate beam surface area and numerical aperture for strong trapping force at each position.
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 enhances the trapping force and maintains a sufficient numerical aperture over long-distance movement, enabling efficient three-dimensional movement and increased freedom in object trapping operations.
Implementation Method 1
The spatial light modulator generates the plural output beams, each of which has been phase-modulated in accordance with the output phase pattern, from the reading light which reaches the spatial light modulator.
Implementation Method 2
The optical traps are formed in, and in the vicinity of, each trapping position by the optical force of the converged beam which reaches the trapping position.
Data Source
AI summary
The present invention relates to optical tweezers having a structure for realizing a great object-trapping force. The optical tweezers form an optical trap for trapping an object in, and in the vicinity of, each of plural trapping positions by converging output beams in each of the trapping positions. The optical tweezers comprise light emitting means for outputting a reading light, hologram generating means for generating an output hologram by arranging plural partial holograms two-dimensionally such that each partial hologram causes an output beam to converge in a corresponding trapping position, and a spatial light modulator for generating plural output beams, each of which has been phase-modulated in accordance with the output hologram, from the reading light which reaches the spatial light modulator. In particular, the hologram generating means arrange partial holograms belonging to a group which corresponds to one of the trapping positions such that the partial holograms are divided between two regions obtained by partitioning the output hologram in two, for example.