Annular Optical Buffer for Monolithic Integration

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Solution Overview

Problem

Current optical buffers face challenges with small capacity, large size, and difficulty in integration, particularly in implementing unordered random storage and reading of optical signals, due to prolonged transmission times and conflicts at output ends in existing recirculation fiber loop systems.

Innovation Solution

An annular optical buffer is introduced, featuring a first bent straight-through waveguide with multiple optical delay waveguide loops and pairs of optical switches, controlled by an external device via a controller that performs optical-to-electrical conversion and generates control signals for unordered random storage and reading, utilizing slow light effect waveguides to manage signal transmission rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If recirculation fiber loops are used to store optical signals, then optical buffering function is achieved, but the device size becomes large and integration becomes difficult

Engineering Contradiction:
Improveoptical buffering functionVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The optical buffer is divided into multiple independently controllable buffer units, each with its own optical delay waveguide loop and optical switches. This segmentation allows each unit to be compact while the overall system achieves large capacity through parallel operation of multiple units.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The optical delay waveguide loops are integrated within a compact photonic circuit structure, with multiple loops nested in a planar configuration. This nesting approach allows multiple buffer units to be packed into a small area, reducing the overall device size while maintaining buffering functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Quantity of substance

If fiber length is increased to prolong transmission time, then optical signal storage capacity is improved, but the device size increases and integration becomes more difficult

Engineering Contradiction:
Improvestorage capacityVSAvoidfiber length
Core Design Contradiction:
Quantity of substanceVSLength of stationary object

Solution Approach 1:

The optical delay is made dynamically controllable through optical switches that can redirect signals to different delay paths or recirculation loops. This dynamic control allows variable storage capacity without requiring fixed long fiber lengths, enabling compact design with adjustable buffering capacity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The transmission delay is controlled by changing the routing parameters through optical switches rather than physically changing fiber length. By adjusting switch states, the effective delay can be varied between different waveguide paths, achieving multiple storage capacities without increasing physical device size.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If optical signals are stored in recirculation fiber loops, then buffering is achieved, but signal conflicts occur at output ends when multiple signals need simultaneous access

Engineering Contradiction:
Improvesignal storageVSAvoidsignal access efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Multiple independently controllable buffer units with separate optical switches at input and output ends allow simultaneous access to different stored signals without conflict. Each unit can be independently accessed, enabling parallel signal retrieval and improving overall system productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The optical switches enable selective routing where signals can be directed to different output paths or held in different buffer units. This selective routing prevents conflicts by allowing the system to manage multiple signal access requests through different paths, recovering from potential conflicts through alternative routing.

Inventive Principle:
Principle #34Discarding and recovering

4Reliability

If traditional optical buffer structures are used, then optical signal storage is achieved, but monolithic integration becomes difficult

Engineering Contradiction:
Improveoptical signal storageVSAvoidmonolithic integration
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple buffer units, optical switches, and waveguide loops are merged into a single integrated photonic circuit structure. The entire optical buffer system is fabricated using standard photonic integration processes, combining previously separate components into one monolithic device that is easier to manufacture and integrate into optical networks.

Inventive Principle:
Principle #5Merging (Combining)

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 monolithic integration and unordered random storage and reading of optical signals, overcoming capacity and size limitations while reducing transmission time and preventing signal conflicts, thereby enhancing the efficiency of optical packet switching systems.

Implementation Method 1

a slow light effect waveguide 104a, disposed on the first bent straight-through waveguide 101a that is between an optical switch closest to the input end and the beamsplitter, and configured to slow a transmission rate of an optical signal transmitted within the slow light effect waveguide 104a

Methodology Applied
Scientific EffectSlow light effect:

Implementation Method 2

perform optical-to-electrical conversion on this part of optical signal to obtain an electrical signal

Methodology Applied
Scientific EffectOptical-to-electrical conversion: Photoelectric Effect

Data Source

PatentEP3079311B1Annular optical buffer and optical signal storage and reading method
Publication Date: 2019.09.18 HUAWEI TECH CO LTD
  • EP3079311B1 patent drawingFigure 1A~1B
  • EP3079311B1 patent drawingFigure 2~3
  • EP3079311B1 patent drawingFigure 4~5A

AI summary

An annular optical buffer (100) and methods for storing and reading an optical signal are disclosed. The optical buffer (100) includes: a first bent straight-through waveguide (101a), functioning as a transmission bus of an optical signal; multiple optical delay waveguide loops (103), configured to temporarily store optical signals; multiple pairs of optical switches (102), whose quantity is the same as that of the multiple optical delay waveguide loops (103), where each pair of optical switches (102) are configured to control on and off of an optical paththat is ontwo arms of the first bent straight-through waveguide (101a) and two sides of an optical delay waveguide loop (103) corresponding to each pair of optical switches (102); a beamsplitter (106), configured to obtain a part of optical signal by splitting the optical signal that is input from an input end and transfer the part of optical signal to a controller (105) through a second bent straight-through waveguide (101c); a slow light effect waveguide (104a), configured to slow a transmission rate of an optical signal transmitted within the slow light effect waveguide; and the controller (105), configured to control storage and read of the optical signal. By means of the foregoing annular optical buffer (100), monolithic integration of an optical buffer and unordered random storage and reading of an optical signal can be implemented.