Asymmetric Beam Splitter for Full-Field Interferential Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Full-field interference imaging systems face limitations in sensitivity due to the maximum amount of light that can be detected from a sample, which is restricted by the reflection and transmission coefficients of the separator element, resulting in only 25% of the incident light being collected, making it challenging to improve image quality without increasing the light intensity or using multiple cameras.
Innovation Solution
The system employs a separator element with a non-equal reflection and transmission coefficient, where at least 90% of the optical power is directed towards the object arm, and a reflection device that deflects incident light waves, allowing for increased optical power backscattered by the sample to be detected without increasing the incident optical power or the number of cameras, thereby enhancing image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a beam splitter with equal reflection and transmission coefficients (50/50) is used, then the interferometer can be balanced, but only 25% of the incident light can be detected from the sample
Solution Approach 1:
The patent applies asymmetry by using a beam splitter with unequal reflection and transmission coefficients (e.g., 90/10 or 80/20) instead of the conventional 50/50 beam splitter. This asymmetric configuration directs the majority of incident light to the object arm where the sample is placed, thereby increasing the amount of backscattered light from the sample that reaches the detector. The asymmetric beam splitter resolves the contradiction by sacrificing perfect interferometer balance to achieve significantly improved light detection efficiency and reduced overall light loss in the system.
2Measurement precision
If the light intensity of the source is increased to improve image quality, then more light can be detected from the sample, but the photon budget is exceeded and sample photosensitivity is damaged
Solution Approach 1:
The patent applies parameter changes by modifying the beam splitter's reflection and transmission coefficients to optimize the distribution of incident light. Instead of increasing the light source intensity, the system changes the optical parameters of the beam splitter to achieve more efficient light utilization. This parameter optimization allows the system to detect sufficient backscattered light from the sample at lower incident light intensities, thereby improving image quality without exceeding the photon budget or damaging photosensitive samples.
3Measurement precision
If multiple cameras are used to detect both reflected and transmitted light flux, then more light from the sample can be recovered, but the system complexity and cost increase
Solution Approach 1:
The patent applies universality by designing a system where a single camera performs multiple functions: it detects both the backscattered light from the sample and the reference light from the mirror through the asymmetric beam splitter configuration. The beam splitter is positioned and oriented such that both light paths are directed to the same detector, eliminating the need for multiple cameras. This multi-functional approach resolves the contradiction by achieving comprehensive light detection capability while maintaining system simplicity and reducing cost.
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 configuration results in more than a threefold increase in the optical power detected from the sample, improving image quality significantly without the need for higher light intensity or additional cameras.
Implementation Method 1
a beam splitter (130) adapted to receive, via an entrance face (130A), incident light waves and adapted to form an object arm for receiving a sample and a reference arm on which a reflecting device (134, 135) is arranged. The beam splitter has a reflection coefficient and a transmission coefficient that are not equal
Implementation Method 2
The beam splitter has a reflection coefficient and a transmission coefficient that are not equal, such that the proportion of the optical power of the incident light waves sent to the object arm is strictly greater than the proportion of the optical power of the light waves sent to the reference arm
Implementation Method 3
The reflecting device on the object arm is adapted to reflect incident light waves in a direction different from the direction of incidence
Implementation Method 4
the interferometer is adapted to produce, when the sample is placed on the object arm of the interferometer, at each point of an imaging field, an interference between a reference wave obtained by reflection of light waves incident on an elementary surface of the reflecting device corresponding to said point of the imaging field and an object wave obtained by backscattering of light waves incident by a voxel of a slice of the sample at a given depth
Implementation Method 5
an illumination channel including a light source for the emission of incident light waves
Implementation Method 6
a detection channel including a two-dimensional image acquisition device positioned in a conjugate plane of the reflection device and adapted to acquire two-dimensional interferometric signals resulting from the interferences produced at each point of the imaging field
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
According to one embodiment, the invention relates to a system (100) for the full-field interferential imaging of a sample (S), comprising an illumination path (101) with a light source (111), an interferometer (103) with at least one first objective (112), and a separating element (130) for receiving incident light waves via an input face (130A) and for forming an object arm for receiving the sample (S) and a reference arm on which a reflection device (134) is arranged, said reflection device being used to reflect incident light waves in a direction different from the direction of incidence. The separator element has a reflection coefficient and a transmission coefficient that are non-equal such that the proportion of the optical power of the incident light waves sent to the object arm is strictly larger than the proportion of the optical power of the light waves sent to the reference arm. The system (100) also comprises a detection path (102) comprising a two-dimensional image acquisition device (121), the illumination path (101) and the detection path (102) comprising a common path comprising said input face of the separator element (130) and being separated by a reflection element (151).