Soliton Laser Pulse State Detection via Dual-Channel Energy and Intensity Analysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Ultrashort pulse lasers in soliton operation face challenges in reliably detecting and distinguishing between single and double or multiple pulse states, requiring complex and costly equipment, which can lead to unintended shifts into double-pulse hysteresis, affecting energy and pulse width optimization.

Innovation Solution

A method using two detectors to infer the laser's operating state by measuring average pulse energy and peak power, with one detector recording total energy and the other peak intensity, allowing for the differentiation between single and multi-pulse states through signal ratio analysis, optimizing the laser operating point.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex detection equipment such as autocorrelators or fast photodiodes with picosecond resolution is used to detect double pulses, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvedouble pulse detection precisionVSAvoiddetection equipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex optical-mechanical detection systems (autocorrelators with moving delay lines) with a stationary interferometric detection system using beam splitters and fixed path lengths. This substitution eliminates mechanical moving parts while maintaining detection capability, directly resolving the contradiction between measurement precision and device complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates an optical copy of the pulse train through beam splitting, where one path serves as a reference and the other as the measurement path. This optical copying approach allows detection without directly measuring the original complex pulse structure, simplifying the detection system while preserving measurement accuracy

Inventive Principle:
Principle #26Copying

2Productivity

If the laser operating point is placed close to the hysteresis boundary to optimize energy and pulse width, then productivity is improved, but reliability deteriorates due to finite probability of emitting double pulses

Engineering Contradiction:
Improveenergy and pulse width optimizationVSAvoidsingle-pulse operation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the interferometric detection system continuously monitors the pulse train and provides real-time information about pulse number and quality. This feedback allows dynamic adjustment of operating parameters to maintain single-pulse operation while optimizing energy and pulse width, resolving the contradiction between productivity and reliability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary detection of the pulse state using the interferometric system before the laser output is used for applications. By detecting potential double-pulse conditions in advance, the system can take corrective action to maintain reliable single-pulse operation while operating near the optimal hysteresis boundary

Inventive Principle:
Principle #10Preliminary action

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 provides a simplified, robust, and cost-effective means to identify pulse states, preventing multi-pulse states and optimizing the laser's operating point, ensuring optimal energy and pulse width, thus enhancing industrial suitability.

Implementation Method 1

a first laser detector (13) designed for measuring average pulse power or pulse energy for one or more pulses

Methodology Applied
Scientific EffectOne-photon absorption: Absorption (EM radiation)

Implementation Method 2

a second laser detector (14) designed for measuring pulse peak power or pulse peak intensity for one or more pulses

Methodology Applied
Scientific EffectTwo-photon absorption: Absorption (EM radiation)

Data Source

PatentEP2019462B1Detection of the occurrence of multiple pulses in a LD pumped soliton laser
Publication Date: 2015.09.23 HIGH Q LASER
  • EP2019462B1 patent drawingFigure 1~2
  • EP2019462B1 patent drawingFigure 3~4
  • EP2019462B1 patent drawingFigure 5~7

AI summary

In a detection method for unwanted double or multiple pulse states in an ultrashort pulse laser system operating in the soliton regime for generating femtosecond or picosecond pulses with an amplifying laser medium for generating laser emission, a laser resonator (10) with at least one resonator mirror and a pump source (9), a first signal µ proportional to the pulse power P(t) or pulse energy averaged over the resonator rotation is measured for the laser emission. A second signal ν proportional to the square of the pulse power P(t) averaged over the resonator rotation is measured for the laser emission, and the occurrence of a double or multiple pulse state is detected by comparing the measured signals µ and ν.For this purpose, part of the laser emission is directed to a first detector (13) to measure the pulse energy, and another part to a second detector (14) to measure the pulse peak intensity using two- or multi-photon absorption. Both values ​​were averaged over the resonator orbital period.