Optical Detector System with Multiple Path Lengths for Tracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional optical detector systems face challenges in maintaining precise alignment of incoming light due to mechanical motions and vibrations, especially in dynamic environments like satellites, which affects the signal-to-noise ratio and requires trade-offs between wide field of view for acquisition and narrow field of view for tracking, leading to inefficiencies and increased complexity.
Innovation Solution
The optical detector system employs different optical path lengths to provide both wide and narrow fields of view simultaneously, using a polarized beam splitter and quarter wave retarders to direct incoming light onto a detector array, allowing for unambiguous determination of the light's relative position and distance, enabling active tracking with fewer adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single optical path length is used, then the device complexity is reduced, but the ability to provide both wide field of view for acquisition and narrow field of view for tracking simultaneously is lost
Solution Approach 1:
The optical detector system divides the incoming light into multiple paths with different optical path lengths. Each path length provides a different field of view (wide for acquisition, narrow for tracking), allowing the system to perform both functions simultaneously without requiring separate detector systems.
Solution Approach 2:
The patent introduces the dimension of optical path length differentiation to achieve multiple field of view capabilities. By varying the optical path length for different light paths while keeping the detector array the same, the system achieves both wide and narrow field of view without adding physical detectors in different locations.
2Measurement precision
If mechanical adjustments are increased to maintain alignment, then tracking accuracy is improved, but mechanical vibrations and complexity increase
Solution Approach 1:
The patent replaces mechanical adjustment mechanisms with an optical solution. By using multiple optical path lengths, the system achieves accurate tracking through optical geometry rather than mechanical repositioning, thereby reducing mechanical vibrations and complexity while maintaining high tracking precision.
3Measurement precision
If a narrow field of view is used for tracking, then alignment precision is improved, but the field of view for acquisition is reduced
Solution Approach 1:
The system segments the field of view requirement into two simultaneous functions: wide field of view for acquisition and narrow field of view for tracking. This is achieved by directing different portions of incoming light through different optical path lengths to the same detector array, allowing both acquisition and precise tracking to occur simultaneously without compromise.
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 allows for efficient acquisition and high-accuracy tracking with reduced iterations, minimizing mechanical vibrations and complexity, thereby maintaining signal alignment effectively in dynamic conditions.
Implementation Method 1
The optical elements include a polarized beam splitter. The first light has a first polarization and the second light has a second polarization
Implementation Method 2
The optical elements include quarter wave retarders
Data Source
AI summary
An optical detector system provides positioning data to facilitate tracking in optical communications. The system provides first and second path lengths to direct light onto an array of photodetectors. Incoming first light with a first polarization is reflected by a polarizing beam splitter (PBS) to the array, resulting in a first path length and a relatively wide field of view (FOV). Incoming second light with a second polarization passes through the PBS, interacts with a first quarter wave retarder (QWR) and a convex mirror, is reflected by the PBS, passes through a second QWR and is reflected by a flat mirror to pass through the PBS again and onto the array. The second light experiences a second path length greater than the first path length, exhibiting a relatively narrow FOV. The resulting spots of light on the array provide information about a position of the incoming beam.