Odd Bounce Image Rotator for Ellipsometer Detector Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electromagnetic radiation detectors exhibit sensitivity to polarization state and beam non-uniformity, leading to reduced measurement accuracy and the need for complex calibration models in ellipsometric and polarimetric systems.
Innovation Solution
Incorporating an odd bounce optical image rotating system with an odd number of reflective elements between the polarizer and analyzer, or between the analyzer and detector, to rotate the beam's polarization state or image, thereby reducing detector polarization state sensitivity and beam non-uniformity effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional detectors are used in ellipsometric systems, then the system structure is simple, but detector polarization state sensitivity and beam non-uniformity reduce measurement accuracy
Solution Approach 1:
The patent introduces an image rotator as an intermediary component between the detector and the optical path. This image rotator rotates the image of the beam incident on the detector, serving as a mediator that decouples the detector's fixed polarization sensitivity from the varying polarization states in the measurement beam, thereby improving measurement accuracy without requiring the detector itself to be complex
Solution Approach 2:
The patent changes the orientation parameter of the beam image relative to the detector by introducing an image rotator. By rotating the image through different angles (typically 0-180 degrees), the system averages out the detector's polarization-dependent response, transforming the measurement parameter from a polarization-sensitive value to a polarization-averaged value that is more accurate
2Measurement precision
If detector polarization state sensitivity is present, then the detector structure remains simple, but complex calibration models are required to compensate for the sensitivity
Solution Approach 1:
The image rotator acts as a physical intermediary that eliminates the need for complex mathematical calibration models. By physically rotating the beam image through various orientations before detection, the system inherently averages out polarization effects, replacing complex post-processing calibration with a simple optical component
Solution Approach 2:
The image rotator enables the detection system to self-correct for polarization sensitivity issues. By continuously or step-wise rotating the image during measurement, the system automatically averages out polarization-dependent detector responses without requiring external calibration procedures or complex data processing algorithms
3Measurement precision
If beam non-uniformity affects the detector, then the optical path remains simple, but measurement accuracy deteriorates due to detector sensitivity to beam non-uniformity
Solution Approach 1:
The image rotator serves as an intermediary that addresses beam non-uniformity effects. By rotating the non-uniform beam image through different orientations, the system ensures that different regions of the non-uniform beam illuminate different regions of the detector over time, effectively averaging out the non-uniformity effects and improving measurement accuracy
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 measurement accuracy by averaging detector signals across different polarization orientations and beam non-uniformities, simplifying calibration models and improving detector performance in ellipsometric and polarimetric systems.
Implementation Method 1
an odd bounce optical image rotating system which comprises an odd number of at least three reflective elements oriented such that a beam of electromagnetic radiation entered thereinto interacts with each of said at least three reflective elements
Data Source
AI summary
Compensating for imperfections in electromagnetic radiation detectors, and more particularly to a system and method for compensating for polarization state sensitivity and/or beam non-uniformity or the like with application in spectroscopic ellipsometers and polarimeters.