Photodetector Calibration Using Known Optical Element
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Solution Overview
Problem
The process of preparing a calibration curve for photodetectors used in spectroscopic analyzers is time-consuming and requires significant equipment, especially when dealing with nonlinear light intensity relationships, making it difficult to maintain or repair devices efficiently.
Innovation Solution
A method that uses an optical element with known wavenumber transmission or reflection characteristics to adjust light intensity, allowing for the calculation of photodetector output values through a simple arithmetic expression by measuring outputs with and without the optical element, thereby linearizing the intensity range and simplifying the calibration process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple reference light beams with different intensities are prepared to measure nonlinear response, then measurement precision is improved, but loss of time increases significantly
Solution Approach 1:
An optical element with known wavenumber transmission or reflection characteristics is introduced as an intermediary in the light path. This element modifies the incident light intensity in a predictable manner, allowing the photodetector's nonlinear response to be characterized using only a single reference light beam, thereby dramatically reducing calibration time while maintaining measurement precision
Solution Approach 2:
The optical element changes the intensity parameter of the incident light in a controlled and known manner. By measuring the photodetector output with and without the optical element, the nonlinear response characteristics can be determined through parameter comparison, eliminating the need for multiple reference beams with different intensities
2Manufacturing precision
If multiple reference light beams are used to cover nonlinear intensity range, then manufacturing precision of calibration curve is improved, but device complexity increases
Solution Approach 1:
The optical element serves as a simple intermediary that can be inserted or removed from the light path. It provides known modification to light intensity without requiring complex equipment, thereby achieving high calibration curve accuracy while minimizing device complexity
Solution Approach 2:
The need for complex multi-beam reference light sources is extracted and replaced by a simple optical element that can be added to an existing single-beam setup. This extraction of complexity maintains calibration accuracy while simplifying the overall device requirements
3Reliability
If comprehensive calibration is performed to account for nonlinear response, then reliability of photodetector output is improved, but ease of repair deteriorates
Solution Approach 1:
The optical element with known characteristics serves as a portable intermediary that can be used for both initial calibration and subsequent re-calibration at the destination. This approach ensures reliable photodetector output while making repair and re-calibration straightforward, as the same simple optical element used during manufacturing can be utilized again without requiring specialized equipment
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
Enables rapid preparation of a photodetector output correction expression with minimal equipment, reducing the time and effort required for calibration and facilitating easy maintenance or re-calibration at the point of delivery.
Implementation Method 1
an optical element having a known wavenumber transmission characteristic or a known wavenumber reflection characteristic
Implementation Method 2
an optical element having a known wavenumber transmission characteristic or a known wavenumber reflection characteristic
Implementation Method 3
a photodetector such as a MCT photodetector is used to detect the intensity of the light beams
Data Source
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AI summary
The present invention makes possible to correct the output of (prepare a calibration curve for) a photodetector 4 used for a spectroscopic analyzer 100 or a spectroscope, in a short period of time with a simple configuration. The present invention is adapted to make light beams emitted from a light source 1 enter the photodetector 4 both when interposing an optical element 6 having known characteristics and when not interposing the optical element 6, and acquire a first output value and a second output value that are the output values of the photodetector 4 with respect to each of light beams that respectively have predetermined multiple wavenumbers and are included in the incident light beams ,and obtain an arithmetic expression for calculating intensity of incident light beams from an output value of the photodetector, using parameters that are a ratio between the first output value and the second output value at each of the predetermined wavenumbers and the wavenumber transmission or reflection characteristic of the optical element.