Dual Interference Optical Module for Mirror Position Detection
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Solution Overview
Problem
Accurate detection of the position of a movable mirror in an optical module is crucial for determining major parameters like wavelength reproducibility and S/N ratio, but existing technologies face challenges in achieving this precision.
Innovation Solution
The optical module incorporates a dual interference optical system where the first light reciprocates once and the second light reciprocates twice between their respective beam splitters and mirrors, creating a phase difference that effectively uses shorter wavelength light for high-resolution position detection, allowing synchronized movement of both mirrors for accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single interference optical system is used for measurement, then the device structure is simple, but the position detection precision of the movable mirror is insufficient
Solution Approach 1:
The optical system is segmented into two independent interference optical systems: a first interference optical system for measurement using first light, and a second interference optical system for position detection using second light. This segmentation allows each system to be optimized for its specific function, with the second system providing high-precision position detection feedback for the movable mirror in the first system.
Solution Approach 2:
The second light and second interference optical system act as an intermediary measurement mechanism. By detecting the position of the movable mirror through the second interference optical system, the system obtains precise position information that serves as feedback for controlling the movable mirror in the first interference optical system, thereby improving overall measurement precision.
2Manufacturing precision
If light reciprocates more times in the interference optical system, then the wavelength resolution improves, but the optical path length increases
Solution Approach 1:
The patent merges the functions of measurement and position detection into a single integrated optical module. The first and second interference optical systems share common components such as the beam splitter and movable mirror, allowing both functions to be performed within a compact structure. This merging enables the system to achieve high wavelength resolution through multiple reciprocations while controlling the overall optical path length through shared components.
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 enables precise detection of the movable mirror's position, enhancing wavelength resolution and S/N ratio while maintaining a balanced and efficient optical system design.
Implementation Method 1
the first light is split into first light travelling to the first movable mirror and first light travelling to the first stationary mirror by the first beam splitter
Implementation Method 2
the first light split to travel to the first movable mirror and the first light split to travel to the first stationary mirror are composed by the first beam splitter
Implementation Method 3
a phase difference occurring on the interference wave of the second light is larger than a phase difference that occurs on the interference wave of the second light in a case in which the second light travelling to the second movable mirror reciprocates
Data Source
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AI summary
An optical module includes an actuator that includes a movable part to be moved along a predetermined direction; a first interference optical system that includes a first movable mirror, a first stationary mirror, and a first beam splitter; and a second interference optical system that includes a second movable mirror, a second stationary mirror, and a second beam splitter. The first interference optical system is adapted so that first light reciprocates m times (m is a natural number) between the first beam splitter and the first movable mirror along the predetermined direction. The second interference optical system is adapted so that second light reciprocates n times (n is a natural number greater than m) between the second beam splitter and the second movable mirror along the predetermined direction.