Azimuthally-Modulated Aperiodic Phase Arrays for Near-Field Spectral Sorting
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Solution Overview
Problem
Current systems are unable to effectively sort spectral components of electromagnetic radiation in the Fresnel near field, particularly within a few microns of a scattering object, limiting their ability to differentiate and separate various spectral components of electromagnetic radiation signals.
Innovation Solution
An optical mask comprising a substrate layer, an opaque layer, and a functional layer, which imparts orbital angular momentum and linear momentum on incoming electromagnetic radiation, allowing for the separation of spectral components by focusing and shifting the radiation based on wavelength, enabling sorting in the Fresnel near field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional spectral sorting systems are used, then spectral components can be sorted in the far-field region, but they cannot sort spectral components in the Fresnel near field within a few microns of a scattering object
Solution Approach 1:
The optical mask is divided into multiple functional layers, each with specific diffractive structures that work together to achieve spectral sorting in the Fresnel near field. The substrate layer, functional layer with azimuthally modulated phase gradient, and output layer are segmented to perform distinct optical functions simultaneously
Solution Approach 2:
The patent introduces azimuthal modulation in the phase gradient, adding an angular dimension to the traditional linear phase gradient. This azimuthal dimension enables the system to sort spectral components in the Fresnel near field by creating wavelength-dependent orbital angular momentum, transforming the sorting mechanism from purely spatial to spatio-angular
2Measurement precision
If an optical mask with azimuthally modulated phase gradient is used, then spectral sorting in the Fresnel near field is achieved, but the device structure becomes more complex
Solution Approach 1:
Multiple optical functions (phase modulation, amplitude modulation, spectral sorting) are merged into a single integrated optical mask structure. The functional layer combines the azimuthally modulated phase gradient with diffractive elements, eliminating the need for separate optical components and reducing overall system complexity despite the advanced functionality
Solution Approach 2:
The optical mask is designed to perform multiple functions simultaneously: it acts as a phase modulator, amplitude modulator, and spectral sorter in a single device. The azimuthally modulated phase gradient structure enables the mask to handle both phase and amplitude modulation while achieving spectral sorting, making the device universally applicable for near-field spectral analysis
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
The solution allows for precise sorting and differentiation of electromagnetic radiation components by transforming spectral differences into spatial intensity variations, enabling accurate identification of different wavelengths and frequencies on an image sensor, even in the Fresnel near field.
Implementation Method 1
The functional layer in conjunction with the opaque layer forms a predefined diffraction pattern that imparts orbital angular momentum and linear momentum on incoming electromagnetic radiation
Implementation Method 2
the imaging plane of the image sensor is in the Fresnel near field
Data Source
AI summary
An electromagnetic radiation sorting device comprises an image sensor having an imaging plane; a substrate layer positioned adjacent to and spaced a distance from the imaging plane of the image sensor such that the imaging plane of the image sensor is in the Fresnel near field; and a functional layer coupled to the substrate layer, the functional layer having a structure that is configured to sort incoming electromagnetic radiation according to frequency by imparting orbital angular momentum and linear momentum on the incoming electromagnetic radiation.