Avalanche Photodiode RNG Bias Control for Unbiased Output

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Solution Overview

Problem

Existing random number generators, both software-based and hardware-based, face limitations such as low-quality output, reliance on external particle sources, and high implementation complexity, which hinder their adoption in general computing due to sensitivity to initial seeds and increased costs.

Innovation Solution

A random number generator utilizing two avalanche photodiodes configured to produce '1' and '0' events based on dark electron initiated avalanches, with a feedback circuit to balance avalanche rates through dynamic bias voltage control, eliminating the need for external particle sources and simplifying implementation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If quantum processes are used for Quantum RNGs, then randomness quality is improved, but device complexity and production cost increase due to requiring particle sources and detectors

Engineering Contradiction:

Improverandomness qualityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the particle source function from external components and integrates it within the avalanche photodiode structure itself. The ion implantation creates trapped charge carriers inside the APD that serve as internal particle sources, eliminating the need for external particle sources and detectors while maintaining quantum-level randomness quality

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the particle source, detector, and random number generation functions into a single integrated avalanche photodiode device. The ion-implanted APD combines the particle generation mechanism (through trapped charge carrier release) and detection mechanism (through avalanche multiplication) in one component, significantly reducing device complexity

Inventive Principle:

Principle #5Merging (Combining)

2Device complexity

If classical analogue RNGs are used, then implementation is simpler, but output quality is low and requires heavy software processing

Engineering Contradiction:

Improveimplementation simplicityVSAvoidoutput quality

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces classical analogue physical processes (such as thermal noise or electronic fluctuations) with quantum-level stochastic processes occurring during avalanche multiplication in the photodiode. This substitution provides inherently high-quality random numbers that are native to computing, eliminating the need for heavy software processing while maintaining implementation simplicity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If software-based RNGs are used, then device complexity is reduced, but randomness quality is low due to algorithm dependence and seed sensitivity

Engineering Contradiction:

Improvedevice complexityVSAvoidrandomness quality

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent implements a self-service mechanism where the avalanche photodiode automatically generates high-quality random numbers through its internal quantum processes. The device requires no external particle sources, no complex control systems, and no software-based seed management. The trapped charge carriers spontaneously release and trigger avalanches, providing continuous high-quality randomness with minimal external intervention

Inventive Principle:

Principle #25Self-service

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

The solution provides high-quality, unbiased random number generation with increased throughput and reduced costs, as it leverages dark electron pulses within the photodiodes, eliminating the need for external particle sources and simplifying implementation, making it suitable for general computing environments.

Implementation Method 1

at least one first avalanche photodiode, APD, configured for producing '1' events based on dark electron initiated avalanches in the first APD

Methodology Applied

Scientific EffectAvalanche breakdown: Avalanche Breakdown

Implementation Method 2

dark electron initiated avalanches

Methodology Applied

Scientific EffectImpact ionization:

Data Source

PatentUS10996927B2Random number generator and method of fabricating the same

Publication Date: 2021.05.04 NATIONAL UNIVERSITY OF SINGAPORE

AI summary

A random number generator, RNG, a method of fabricating the same, and a method of generating a random number. The RNG, comprises at least one first avalanche photodiode, APD, configured for producing “1” events based on dark electron initiated avalanches in the first APD; at least one second avalanche photodiode, APD, configured for producing “0” events based on dark electron initiated avalanches in the second APD; and a feedback circuit configured for substantially evening out the respective numbers of generated avalanches in the first and second APDs by independently controlling respective dynamic bias voltages of the first and second APDs.