Liquid Crystal Microlens Wavefront Analyzer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical wavefront analyzers face challenges with inflexible microlenses of fixed focal length and complex structures, particularly in adjusting focal length and refractive index, which affects their efficiency and ease of use in applications like astronomical observations and ophthalmological measurements.
Innovation Solution
An optical wavefront analyzer using an array of convergent microlenses formed from a layer of liquid crystal operating in transmission, with a matrix of electrodes defining liquid crystal pixels whose refractive index is controllable by voltage, allowing for monotonic radial variation in refractive index to adjust microlens dimensions, position, and focal length, operating in both refractive and non-diffractive modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed focal length glass microlenses are used, then manufacturing is simple, but flexibility and ease of operation deteriorate due to inability to adjust focal length and position
Solution Approach 1:
The patent uses liquid crystal microlenses whose refractive index can be dynamically adjusted by applying different voltages to electrode pixels. This allows the focal length and position of each microlens to be changed in real-time, transforming a static optical system into a dynamic one that can adapt to different measurement requirements without physical reconfiguration.
Solution Approach 2:
The invention changes the refractive index parameter of the microlens material from a fixed value (glass) to a variable value (liquid crystal). By controlling the voltage applied to each liquid crystal pixel, the refractive index can be precisely adjusted, thereby controlling the focal length and position of each microlens independently through electrical parameters rather than physical manufacturing changes.
2Adaptability or versatility
If liquid crystal microlenses with refractive index steps are used, then adaptability improves, but manufacturing precision deteriorates due to difficulty in achieving continuous refractive index variation
Solution Approach 1:
The patent replaces the mechanical/optical approach of creating physical refractive index steps (as in Fresnel lenses) with an electrical control system. By applying different voltages to each liquid crystal pixel through an electrode matrix, the refractive index distribution is controlled electrically rather than through mechanical manufacturing processes, achieving continuous variation without physical discontinuities.
Solution Approach 2:
The invention uses voltage as a control parameter to continuously adjust the refractive index of liquid crystal pixels. By varying the voltage applied to each pixel, any desired refractive index value within the liquid crystal's range can be achieved, providing continuous and precise control over the microlens optical properties without the discrete steps inherent in manufactured lens structures.
3Ease of manufacture
If diffractive gratings are used for microlenses, then manufacturing is simplified, but measurement precision deteriorates due to strong wavelength dependence of focal length
Solution Approach 1:
The patent changes the operating principle of microlenses from diffractive (strongly wavelength-dependent) to refractive (weakly wavelength-dependent) by using liquid crystal with controllable refractive index. This allows the system to maintain manufacturing simplicity while achieving wavelength-insensitive focal length control, thereby improving measurement precision across different wavelengths.
Solution Approach 2:
The invention discards the diffractive grating approach that causes wavelength-dependent focal length variations and recovers the refractive lens principle with liquid crystal material. This allows the system to eliminate the harmful wavelength dependence while retaining the ability to control focal length through material property adjustment rather than geometric structure.
4Adaptability or versatility
If reflective liquid crystal arrays are used, then adaptability improves, but device complexity worsens due to complex analyzer structure
Solution Approach 1:
The patent inverts the conventional reflective liquid crystal approach by using transmissive liquid crystal microlenses. Instead of reflecting light through programmable patterns, the system transmits light through liquid crystal pixels that directly modulate the refractive index, simplifying the overall analyzer structure while maintaining full programmability and adaptability of the microlens array.
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 solution provides a more efficient and simpler wavefront analyzer with adjustable microlenses, allowing for precise control of focal length and refractive index, reducing dependence on wavelength and improving flexibility and accuracy in wavefront analysis.
Implementation Method 1
a matrix of electrodes defining liquid crystal pixels whose refractive index is controllable by voltage individually applied to each electrode
Implementation Method 2
an array of converging microlenses for subdividing an incident wavefront into multiple beams and creating for each beam a respective focal point
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to optical wave front analyzers. Provided is a wave front analyzer that includes an array of adjustable convergent microlenses for subdividing an incident wave front into multiple beams and generating a respective focal point for each beam, and an array of light-sensitive detectors provided behind the microlense array for detecting the positions of said focal points. The microlens array consists of a liquid crystal layer (10) that transmissively operates and is provided with an array of electrodes defining liquid crystal pixels, the index of refraction of which is controllable by means of a voltage individually applied to each electrode. Each convergent microlens (μL1, μL2) includes a subassembly of pixels grouped into a region constituting the microlens, the indices of the pixels of a subassembly radially varying in a monotonic manner when moving away from a central point (O1, O2) of the region toward the edges of the region, such that the microlens operates in a refractive mode. The number, position, size, and focal length of the microlenses can be adjusted using the profile of voltages applied to the array of pixels.