Phase-Sensitive SPR Sensing Using Multi-Angle Beam Reflection
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Solution Overview
Problem
Current Surface Plasmon Resonance (SPR) detection devices face limitations in achieving a wide dynamic range and precise phase-sensitive measurements, which restrict their ability to accurately characterize samples with varying refractive indices.
Innovation Solution
A phase-sensitive SPR sensing apparatus that reflects a testing beam at multiple angles, utilizing a detecting unit to compare the phase of the reflected beam with a reference beam, and includes a focusing unit with a cylindrical lens and a detection unit comprising a photodetector array and phase meter, enabling the detection of differential phase changes across a wide range of illumination angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single-angle SPR measurement is used, then the device complexity is low, but the dynamic range and measurement precision are limited
Solution Approach 1:
The detection is segmented into multiple discrete angle measurements rather than a single measurement. The apparatus divides the angular space into multiple measurement points, with each detector or measurement cycle capturing phase information at a specific angle. This segmentation enables wider dynamic range and higher precision by collecting phase data across multiple angles, which are then processed to extract enhanced sample characteristics.
Solution Approach 2:
The measurement system transitions from single-angle (one-dimensional) to multi-angle (adding an angular dimension). By introducing the angle of incidence as an additional measurement dimension, the system captures phase information across a range of angles rather than a single point, thereby expanding the dynamic range and improving measurement precision through angular diversity.
2Adaptability or versatility
If multiple detection angles are implemented, then the dynamic range is widened, but the device complexity increases
Solution Approach 1:
The detection apparatus is designed with multi-functionality to handle multiple detection angles simultaneously or sequentially. The system can detect reflected beams at various angles using either multiple detectors arranged at different angles or a single detector that scans through multiple angles. This universal detection capability widens the dynamic range while managing complexity through integrated design.
Solution Approach 2:
An intermediary optical element (such as a beam splitter, mirror, or scanning mechanism) is introduced to direct the reflected beams at multiple angles to the detector(s). This intermediary component enables the system to capture phase information across a wide angular range without requiring complex multi-detector arrangements, thereby widening the dynamic range while controlling device complexity.
3Measurement precision
If phase comparison with reference beam is performed, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
A beam splitter is used as an intermediary to divide the incident beam into a reference beam and a probing beam. The reference beam bypasses the sample while the probing beam interacts with the sample. By comparing the phase of the reflected probing beam with the reference beam, the system achieves high measurement precision. The beam splitter and subsequent optical components serve as intermediaries that enable precise phase comparison while managing system complexity.
4Productivity
If a photodetector array is used for multi-angle detection, then the detection capability is enhanced, but the manufacturing precision requirements increase
Solution Approach 1:
The system incorporates self-alignment or self-calibration mechanisms that reduce the stringency of manufacturing precision requirements. Optical elements are designed to automatically align themselves during operation, or the system includes calibration routines that compensate for manufacturing tolerances. This self-service approach enables the photodetector array to achieve accurate multi-angle detection without requiring extremely tight manufacturing precision.
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 dynamic range and precision of SPR measurements, allowing for better characterization of samples with varying refractive indices, as demonstrated by experimental and simulated results showing improved resolution and sensitivity.
Implementation Method 1
Surface Plasmon Resonance (SPR) detection devices
Implementation Method 2
a sensing surface to reflect a testing beam of electromagnetic radiation
Implementation Method 3
the detecting unit compares the phase of said reflected testing beam with the phase of a reference beam
Implementation Method 4
the reference beam and said testing beam are generated by a beam splitter
Implementation Method 5
a focussing unit to focus said testing beam
Implementation Method 6
the focussing unit comprises a cylindrical lens
Implementation Method 7
a detection unit comprising a photodetector array
Implementation Method 8
a polarizer for selecting an intensity ratio between the p- and s-polarization components of the emitted electromagnetic radiation
Implementation Method 9
detecting the interfered electromagnetic radiation from said polariser, and a processor for comparing the phase pattern of the interfered electromagnetic radiation and the reference beam
Data Source
AI summary
There is disclosed a phase sensitive surface plasmon resonance sensing apparatus wherein a testing beam may be reflected from a sensing surface at a plurality of angles. There are also disclosed methods for surface plasmon resonance sensing.