Tunable Wavelength Laser Control via Stored Driving Conditions

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Solution Overview

Problem

Tunable wavelength lasers face long start-up times due to the inability to control oscillation at wavelengths other than pre-defined grid wavelengths, as existing methods require lengthy calculations for setting values.

Innovation Solution

A method that involves acquiring driving conditions for a tunable wavelength laser, calculating and applying feedback control to adjust the oscillation wavelength based on a wavelength sensing unit's output and a target value, and storing these conditions for future reference, allowing the laser to oscillate at any desired wavelength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If calculation-based setting values are used to enable oscillation at non-grid wavelengths, then wavelength flexibility is improved, but start-up time increases

Engineering Contradiction:

Improvewavelength flexibilityVSAvoidstart-up time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent stores pre-calculated setting values for multiple wavelengths in a memory device before operation. When a wavelength is needed, the system simply retrieves the pre-stored values rather than calculating them in real-time, thus enabling wavelength flexibility without increasing start-up time.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent prepares and stores setting values for various wavelengths in advance during manufacturing or initialization. This beforehand preparation cushions against the time penalty that would otherwise occur during actual wavelength switching operations, allowing immediate retrieval and application of appropriate settings.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Loss of time

If grid wavelength control is used, then start-up time is reduced, but wavelength selection flexibility is lost

Engineering Contradiction:

Improvestart-up timeVSAvoidwavelength selection flexibility

Core Design Contradiction:

Loss of timeVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal control system that can handle both grid wavelengths (for fast start-up) and non-grid wavelengths (for flexibility). The memory stores setting values for multiple wavelengths, allowing the system to function efficiently across different wavelength requirements without being limited to a single wavelength set.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the control parameter from fixed grid wavelengths to variable wavelengths by storing and retrieving different setting values from memory. This allows the system to switch between grid and non-grid wavelengths as needed, maintaining fast start-up performance while gaining wavelength selection flexibility.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If real-time calculation of setting values is performed, then wavelength precision is improved, but processing time increases

Engineering Contradiction:

Improvewavelength precisionVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs the complex calculation work in advance during system initialization or manufacturing, storing the results in memory. This preliminary action eliminates the need for real-time calculations during operation, maintaining wavelength precision while reducing processing time to simple memory retrieval operations.

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 significantly shortens the start-up time of tunable wavelength lasers by enabling oscillation at any wavelength, improving reliability and efficiency by utilizing stored driving conditions.

Implementation Method 1

a wavelength sensing unit configured to sense an oscillation wavelength of the tunable wavelength laser

Methodology Applied

Scientific EffectWavelength sensing:

Data Source

PatentUS9819148B2Method for controlling tunable wavelength laser

Publication Date: 2017.11.14 SUMITOMO ELECTRIC DEVICE INNOVATIONS

AI summary

A driving condition for causing the tunable wavelength laser to conduct laser oscillation at a first wavelength is acquired. a driving condition for causing the tunable wavelength laser to conduct laser oscillation at the second wavelength is calculated. The tunable wavelength laser is driven based on the driving condition of the second wavelength, feedback control that changes the driving condition of the tunable wavelength laser based on a difference between an output of the wavelength sensing unit and the target value is performed, and the tunable wavelength laser is caused to oscillate at the second wavelength. The driving condition of the tunable wavelength laser obtained by the feedback control when oscillation has occurred at the second wavelength is stored in the memory. Thereafter, the tunable wavelength laser is driven with reference to the stored driving condition of the tunable wavelength laser.