Microscope Optical Filter Device Using Achromatic Polarization Manipulator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical filter devices for microscopes, particularly dichroic mirrors, face limitations in spectral selectivity and suppression of partial spectral regions, especially when used with broad-band or multiline light sources, leading to suboptimal performance in fluorescence microscopy.
Innovation Solution
Incorporating a static achromatic polarization manipulator and dichroic mirrors arranged to allow 0° incidence, enabling bidirectional spectral filtering with enhanced suppression and selectivity, along with additional polarization modulators and dichroic mirrors to achieve cumulative spectral blocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dichroic mirrors are used at perpendicular incidence (0°) for maximum selectivity and suppression, then spectral selectivity and suppression are improved, but coupling of multiple beams becomes impossible
Solution Approach 1:
The optical system is segmented into separate illumination and detection beam paths that are spatially separated. The illumination beam path operates at 0° incidence for maximum spectral selectivity, while the detection beam path is directed at 90° angle, allowing both functions to coexist without interfering with each other's optimal performance
Solution Approach 2:
The problem is solved by transitioning from a single-beam path configuration to a two-dimensional beam path arrangement. The illumination beam travels horizontally through the dichroic mirror at 0°, while the detection beam path is routed vertically at 90°, utilizing spatial dimensionality to resolve the contradiction between spectral performance and multi-beam coupling capability
2Ease of operation
If dichroic mirrors are used at 45° incidence for 90° beam path arrangement, then beam path configuration is simplified, but spectral selectivity and suppression are reduced
Solution Approach 1:
The beam path is segmented into distinct illumination and detection routes with different incidence angles on the dichroic mirror. This segmentation allows each beam path to be optimized independently for its specific function rather than requiring a compromise configuration
3Measurement precision
If smaller angles of incidence are used to improve suppression in transmission, then suppression of partial spectral region is improved, but polarization splitting occurs which degrades suppression characteristics near filter edges
Solution Approach 1:
Different regions of the optical system are assigned different optical properties and functions. The dichroic mirror surface is designed with spatially varying reflectivity and transmission characteristics, with the 0° incidence region optimized for maximum spectral selectivity and suppression, while other regions handle beam steering and polarization management to maintain overall system reliability
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 allows for higher spectral selectivity and suppression of partial spectral regions, effectively filtering excitation light and improving measurement accuracy in fluorescence microscopy, especially with broad-band or multiline light sources.
Implementation Method 1
a polarizing beamsplitter (21A, 21B) which separates incident light into two polarization components which are orthogonal to one another and reflects one and transmits the other
Implementation Method 2
the polarization manipulator is constructed (and aligned) in such a way that it (effectively) rotates by 90° (relative to the polarization direction prior to the first passage) a polarization direction of light which a) exits the polarizing beamsplitter at the first input/output
Implementation Method 3
dichroic mirrors have maximum selectivity and suppression at perpendicular incidence (0°)
Implementation Method 4
Optical filter devices are used for removing a partial spectral region (which can also consist of a plurality of separate bands) from a light beam
Data Source
AI summary
An optical filter device having a polarizing beamsplitter, an achromatic polarization manipulator, and at least one dichroic mirror. The polarization manipulator is arranged optically between a first input/output of the polarizing beamsplitter and the dichroic mirror. The polarization manipulator is also constructed in such a way that it effects a 90-degree rotation of a polarization direction of light which a) exits the polarizing beamsplitter at the first input/output, b) traverses the polarization manipulator, c) is reflected by the dichroic mirror, and d) again traverses the polarization manipulator. The optical filter device can also be used as beamsplitter.