Photodetector Matrix Pulse Detection Without an Auxiliary Sensor

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current laser pulse detection systems require an auxiliary sensor for synchronization, leading to increased complexity, cost, and performance limitations due to the need for two sensors, making the system inhomogeneous and limited by the single-element synchronization detector.

Innovation Solution

A method that allows a matrix of photodetectors to autonomously detect laser pulses by adjusting its integration period based on the pulse repetition period and speed of approach, eliminating the need for an auxiliary sensor, and incorporating a tracking phase with a modified integration period to ensure accurate detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an auxiliary sensor is used for synchronization, then the detection system can accurately detect laser pulses, but the system complexity and cost increase due to requiring two sensors

Engineering Contradiction:
Improvedetection accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the synchronization function from a separate auxiliary sensor and integrates it into the matrix photodetector system itself. The matrix autonomously detects the laser pulse arrival instant by monitoring its own input signal, eliminating the need for the auxiliary sensor while maintaining accurate synchronization capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The matrix photodetector is designed to perform multiple functions: both the primary detection of spatial light distribution and the secondary function of temporal synchronization. By making the matrix autonomous in detecting pulse arrival, it becomes a multi-functional device that no longer requires a dedicated auxiliary sensor for synchronization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If an auxiliary sensor is used for synchronization, then the system can trigger integration phases, but the performance is limited by the single-element synchronization detector

Engineering Contradiction:
Improveintegration triggering capabilityVSAvoiddetection performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent merges the synchronization detection function with the matrix photodetector's primary detection function. Instead of using a separate single-element auxiliary sensor, the system combines both functions in the matrix, allowing the same device to perform both spatial detection and temporal synchronization with equal performance.

Inventive Principle:
Principle #5Merging (Combining)

3Quantity of substance

If the matrix integration time is increased to capture laser pulses, then more photons are detected, but the integration period becomes too long to synchronize with pulsed illumination

Engineering Contradiction:
Improvephoton detection quantityVSAvoidintegration time
Core Design Contradiction:
Quantity of substanceVSDuration of action of moving object

Solution Approach 1:

The system performs preliminary detection of the laser pulse arrival instant by the matrix before the main integration phase. By first detecting when the pulse arrives and then triggering the integration at the optimal moment, the system ensures maximum photon capture during the integration window without requiring an excessively long integration period.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The integration period is made dynamic rather than fixed. The system adjusts the integration timing and duration based on the actual pulse arrival time detected by the matrix, allowing optimal synchronization for each pulse while maintaining efficient photon collection.

Inventive Principle:
Principle #15Dynamics

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 enhances detection efficiency and reduces costs by eliminating the need for an auxiliary sensor, making the matrix an autonomous pulse detector with improved sensitivity and performance.

Implementation Method 1

a matrix of photodetectors performs a conversion of photons into electrons in proportion to the illumination received by each photodetector in its spectral band of sensitivity

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP2095507B1Method for detecting laser pulses using a photodetector matrix
Publication Date: 2011.12.21 THALES SA
  • EP2095507B1 patent drawingFigure 1
  • EP2095507B1 patent drawingFigure 2
  • EP2095507B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a method for detecting laser pulses having a repetition period T1 with an amplitude jitter tj, detected using a matrix of photodetectors, said method including the step of integrating charges in a predetermined duration ti and according to a period Tm larger than a minimal period Tmin. The detection is carried out sequentially in the following manner. 1 : detection of a signal having the time characteristics of the expected laser code using the matrix and without using an auxiliary sensor; this phase involves using an integration period equal to the smallest submultiple of Tl+ti-tj larger than Tmin, wherein ti is the matrix integration duration and Tmin is the minimal integration period. 2 : confirming the detection of this first pulse and detecting the following laser pulses; this phase involves using an integration period T1' which is different from the period T1 of the pulses outputted by the laser due to the closing speed between the pulse generator and the matrix. The method can be used for detecting laser pulses without using an auxiliary sensor as the matrix becomes an autonomous pulse detector.