Structured Illumination Digital Holography for Super-Resolution Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digital holographic microscopy faces limitations in spatial resolution due to optical diffraction limits and mechanical scanning-induced perturbations, leading to reduced axial phase accuracy and sensitivity to environmental vibrations.
Innovation Solution
Structured illumination digital holography using a spatial light modulator and binary random number encoding to generate Moiré fringes, allowing for real-time image reconstruction without complex optical architectures, and overcoming the need for time-multiplexing by synthesizing high and low-frequency bandpass spectra in a single exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical galvanometer is used to rotate incident angle of the beam to scan the object, then spatial resolution can be enhanced, but additional perturbations are caused and axial phase accuracy is reduced
Solution Approach 1:
The patent replaces the mechanical galvanometer scanning system with a spatial light modulator that uses optical phase modulation to achieve angular multiplexing. The SLM modulates the phase of the illumination light to generate structured illumination patterns at different angles without mechanical movement, thereby eliminating mechanical perturbations while maintaining the ability to capture high-frequency object information for super-resolution imaging.
2Measurement precision
If complex optical architecture is used to avoid crosstalk of individual frequency bands, then frequency separation is achieved, but system complexity increases and sensitivity to environmental perturbation increases
Solution Approach 1:
The patent replaces complex optical filtering architectures with computational methods. The spatial light modulator encodes multiple frequency band information into a single holographic interference pattern using phase modulation. Advanced signal processing and algorithms are then applied to the captured hologram to separate and reconstruct different frequency bands, achieving frequency separation without complex optical components and reducing sensitivity to environmental perturbations.
Solution Approach 2:
The patent transforms the problem from spatial domain frequency separation to temporal and computational domain processing. By encoding frequency band information in the phase dimension of the holographic interference pattern and using computational algorithms to decode and separate the bands, the system achieves frequency separation without additional spatial optical components.
3Measurement precision
If time multiplexing is used to separate spectral overlap with at least two sheets of phase shift patterns, then spectral overlap is resolved, but axial phase accuracy is susceptible to environmental vibration and signal-to-noise ratio is affected
Solution Approach 1:
The patent combines multiple frequency band information and spectral data into a single holographic interference pattern captured in one exposure. The spatial light modulator encodes information from different frequency bands and phase shifts simultaneously in the spatial and phase domains of the hologram. Signal processing algorithms then extract and separate the spectral information, achieving spectral separation without time multiplexing and thereby eliminating sensitivity to environmental vibrations during the measurement process.
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
Enhances spatial resolution and axial phase accuracy, reducing sensitivity to environmental perturbations and achieving high-resolution wavefront reconstruction without the need for mechanical scanning or complex optical systems.
Implementation Method 1
interfering an encoded structured object wave with a reference wave to form a single sheet of digital hologram
Implementation Method 2
using a diffraction grating for the incident light separating into the zero order (0th) and a positive one and negative one order diffraction (±1st) terms
Implementation Method 3
uses structured illumination for illuminating an object for generating Moiré fringes to make digital holographic recording
Implementation Method 4
binary random number encoding to generate Moiré fringes, allowing for real-time image reconstruction without complex optical architectures
Implementation Method 5
an illumination objective lens set to amplify or reduce the structured illumination for illuminating on an object to be measured
Implementation Method 6
a plurality of mirrors for changing optical path of the light source
Data Source
AI summary
A method of structured illumination digital holography includes: (a) providing a structured illumination generating unit and binarization random number encoding unit to generate a coded structured illumination pattern; (b) sampling at least two patterns with phase shift which synthesized as a single structured illumination pattern to be encoded; (c) forming a single digital hologram, and wavefront reconstructing the single digital hologram; (d) performing a compressive sensing approach to recover the object wave with at least two phase shift patterns; and (e) reconstructing the separation of overlap spectrum, to obtain an image covering bandpass spectrum with different high frequency and low frequency.