MSDS-DBR Laser Tuning via Digital Bias Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing tunable lasers require expensive and power-hungry electronic circuitry for continuous wavelength tunability, often relying on digital-to-analog conversion (DAC) chips, and have complex drive schemes due to shared ground electrodes in vertical p-i-n diode junctions.

Innovation Solution

A multisection digital supermode-distributed Bragg reflector (MSDS-DBR) design with horizontal p-i-n diode junctions and discrete electrical contacts allows for independent biasing of each grating sub-region, eliminating the need for DACs and simplifying the drive circuitry by using a common electrode structure for efficient wavelength tuning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If continuously tunable lasers use DAC chips for wavelength control, then wavelength tunability is achieved, but cost and power consumption increase significantly

Engineering Contradiction:
Improvewavelength tunabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and eliminates the DAC chip from the laser system by implementing direct digital control of the DBR grating sections. Each grating section is controlled by independent digital signals that directly modulate the refractive index, removing the need for analog conversion and associated power-hungry electronics while maintaining full wavelength tunability across the gain spectrum.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/electronic DAC conversion system with a direct optical control mechanism. Digital signals are applied directly to the DBR grating sections through p-i-n diodes, which modulate the refractive index to control wavelength selection. This substitution eliminates the intermediate analog conversion stage, reducing power consumption and component complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If vertically oriented p-i-n diode junctions with common ground are used, then manufacturing is simplified, but drive scheme complexity increases due to shared electrodes

Engineering Contradiction:
Improvefabrication simplicityVSAvoiddrive scheme complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent segments the DBR structure into multiple independently controllable grating sections, each with its own p-i-n diode junction. This segmentation allows each section to be controlled by independent digital signals without sharing ground electrodes, simplifying the drive scheme while maintaining manufacturing simplicity through standard vertical junction fabrication.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-plane electrode configuration to a multi-dimensional control architecture where each grating section has independent electrical access. This dimensional expansion in the electrical control space allows simultaneous independent control of multiple grating sections without electrode sharing, reducing drive scheme complexity while preserving vertical junction manufacturing advantages.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 MSDS-DBR design reduces power consumption and costs by enabling tunable lasers without DACs, providing flexible and efficient wavelength control through independent biasing of each spectral sub-band, allowing for faster operation and reduced complexity in drive schemes.

Implementation Method 1

each grating sub-region being configured to pass or reflect light of its spectral sub-band when an electrical bias is provided between its positive and negative electrical contacts

Methodology Applied
Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentUS9997890B2Discrete wavelength tunable laser
Publication Date: 2018.06.12 ROCKLEY PHOTONICS LTD

AI summary

A multisection digital supermode-distributed Bragg reflector (MSDS-DBR) comprising: a plurality P of digital supermode Bragg reflector (DS-DBR) grating sections arranged along a waveguide; wherein each DS-DBR grating section is configured to pass or reflect light over a given spectral region, the given spectral region being different from the spectral regions of the other DS-DBR grating sections; wherein each DS-DBR grating section comprises a plurality M of grating sub-regions, each sub-region corresponding to a spectral sub-band within the spectral region of the DS-DBR grating section, and wherein each grating sub-region includes a positive electrical contact and a negative electrical contact; said grating sub-region being configured to pass or reflect light of its spectral sub-band when an electrical bias is provided between its positive and negative electrical contacts.