Optical Switch Fixed-Wavelength Light Sources Tunable Filters

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Solution Overview

Problem

Conventional large-scale wavelength routing optical switch devices face challenges with high costs and complexity due to the need for numerous expensive wavelength-tunable light sources and complicated tuning-control mechanisms, especially when scaling beyond 1000 ports, and struggle with the availability and cost-effectiveness of components.

Innovation Solution

The optical switch device employs fixed-wavelength light sources and tunable filters, where the wavelengths of the light sources are fixed and only the tunable filters select the appropriate wavelengths for output, reducing the complexity and cost by using inexpensive components and simplifying the light source configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If wavelength-tunable light sources are used in conventional optical switch devices, then channel switching capability is achieved, but device cost and complexity increase significantly

Engineering Contradiction:

Improvechannel switching capabilityVSAvoidtuning-control mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Instead of using wavelength-tunable light sources where the light source wavelength is adjusted to select channels, this patent inverts the approach by using fixed-wavelength light sources and adjusting the tunable filter wavelength to select channels. This inversion eliminates the complex tuning-control mechanism of the light sources while achieving the same channel switching capability.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces expensive wavelength-tunable light sources with inexpensive fixed-wavelength light sources. The wavelength selection function is transferred to tunable filters, which are cheaper and simpler components, thereby reducing device cost and complexity while maintaining the optical switching function.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Adaptability or versatility

If the number of ports is increased beyond 1000, then larger scale switching capability is achieved, but device cost and complexity increase proportionally

Engineering Contradiction:

Improveport count scalabilityVSAvoidnumber of light sources and control mechanisms

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the wavelength selection function across multiple tunable filters instead of requiring a single complex wavelength-tunable light source for each port. This segmentation allows the system to scale to large port counts (beyond 1000) by using simpler, more affordable tunable filter components rather than proportionally increasing the number and cost of complex light sources.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If wavelength-tunable light sources are used, then optical switching function is achieved, but power consumption increases

Engineering Contradiction:

Improveoptical switching functionVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces power-intensive wavelength-tunable light sources with lower-power fixed-wavelength light sources. The energy consumption is shifted to the tunable filters, which consume less power than wavelength-tunable light sources, thereby reducing the overall power consumption of the optical switch device while maintaining the optical switching function.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 configuration results in a lower-cost, scalable optical switch device capable of handling large port counts, such as 1000x1000, with reduced power consumption and simplified design, suitable for data centers.

Implementation Method 1

MN tunable filters each of which selects a light beam with any one wavelength from among the light beams with the at most M different wavelengths multiplexed by the one multiplexer selected by a corresponding one of the MN N×1 optical switches

Methodology Applied

Scientific EffectWavelength selection: Filter (optical)

Data Source

PatentUS10448128B2Optical switch device

Publication Date: 2019.10.15 NAGOYA UNIVERSITY

AI summary

A wavelength routing SW is a large-scale optical switch device of a conventional technique, and it requires as many wavelength-tunable light sources as the number of input ports. For the wavelength-tunable light sources to achieve a stable oscillating operation across a wide wavelength range, a complicated control mechanism is necessary. This has been an obstacle in providing a large-scale optical switch device in terms of cost and circuit scale. A wavelength routing SW in the present disclosure includes N wavelength group generators, a splitting-selection unit, and MN tunable filters. Each wavelength group generator includes M fixed-wavelength light sources. Inexpensive general-purpose devices that require no control mechanism for wavelength tuning can be used as the fixed-wavelength light source. The channel loss in the optical switch device can also be reduced by using light sources with a limited narrow range of tunable wavelengths and the wavelength-dependent output port selecting function of an AWG.