Laser Repetition Frequency Control via Phase Difference Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems fail to dynamically adjust the difference in repetition frequency between two lasers, limiting their operational flexibility and precision.
Innovation Solution
A repetition frequency control device comprising a master laser, a slave laser, reference and measurement comparators, a phase difference detector, a loop filter, and an adder, which adjusts the slave laser's repetition frequency based on a control signal to match a predetermined value, allowing for dynamic changes in the frequency difference between the two lasers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the repetition frequency difference between two lasers is kept constant by independent control, then the system stability is maintained, but the operational flexibility and precision are limited
Solution Approach 1:
The patent implements a feedback control system where the repetition frequency of the first laser is used as a reference, and the repetition frequency of the second laser is adjusted based on the phase difference detection between the two lasers. This feedback mechanism enables dynamic adjustment of the frequency difference while maintaining stability, thereby improving operational flexibility without requiring completely independent control of both lasers.
Solution Approach 2:
The control system uses a universal reference signal from the first laser to control both the frequency stabilization and the frequency difference adjustment. By making the first laser's repetition frequency serve multiple purposes (reference for stability and basis for frequency difference control), the system reduces complexity while maintaining both stability and flexibility.
2Measurement precision
If the repetition frequency of the slave laser is dynamically adjusted, then the precision and flexibility are improved, but the system complexity increases
Solution Approach 1:
The patent employs a phase difference detector that continuously monitors the phase relationship between the first and second lasers, feeding this information back to adjust the repetition frequency of the second laser. This feedback loop enables precise frequency control by dynamically compensating for drift and variations, achieving high precision without overly complex control mechanisms.
Solution Approach 2:
The patent introduces a phase difference detector as an intermediary component that simplifies the control task. Instead of directly controlling the frequency difference between two independent lasers, the system uses the phase difference signal as an intermediate parameter to indirectly and more precisely control the frequency relationship, reducing the complexity of direct frequency control.
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 precise and flexible control of laser repetition frequencies, maintaining the slave laser's frequency in sync with the master laser, even with fluctuations, thereby enhancing the system's operational flexibility and accuracy.
Implementation Method 1
the slave laser may include a piezo element; the output from the adder may be fed to the piezo element; and the resonator length of the slave laser may be changed by extension and contraction of the piezo element
Implementation Method 2
a loop filter that removes a high-frequency component of an output from the phase difference detector
Implementation Method 3
the repetition frequency control device may include: a photoelectric conversion unit that receives the slave laser light pulse
Data Source
AI summary
According to the repetition frequency control device, a master laser outputs a master laser light pulse the repetition frequency of which is controlled to a predetermined value. A slave laser outputs a slave laser light pulse. A reference comparator compares a voltage of a reference electric signal the repetition frequency of which is the predetermined value and a predetermined voltage with each other, thereby outputting a result thereof. A measurement comparator compares a voltage based on a light intensity of the slave laser light pulse and the predetermined voltage with each other, thereby outputting a result thereof. A phase difference detector detects a phase difference between the output from the reference comparator and the output from the measurement comparator. A loop filter removes a high-frequency component of an output from the phase difference detector.