Semiconductor Laser Ridge Stripe Segmentation for Degradation Isolation

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Solution Overview

Problem

Existing semiconductor laser devices are prone to degradation spreading from a degraded portion of the end face to the rest of the end face, leading to a significant reduction in optical power output.

Innovation Solution

The semiconductor laser device features a substrate with multiple ridge stripes separated by insulating sections and electrodes, where each ridge stripe includes a lower cladding layer, active layer, upper cladding layer, and contact layer, with a top surface electrode extending over the ridge stripes and filling the spaces between them, preventing degradation from spreading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a multibeam semiconductor laser device is used, then optical power output is improved, but degradation spreads from a degraded portion to the rest of the end face

Engineering Contradiction:

Improveoptical power outputVSAvoiddegradation resistance

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The active layer is divided into multiple independent ridge stripes separated by separation sections. Each ridge stripe operates as an independent laser beam source, and degradation in one ridge stripe does not spread to other ridge stripes due to the isolation provided by the separation sections, thus maintaining reliability while providing multibeam output

Inventive Principle:

Principle #1Segmentation

2Power

If the end face is entirely degraded, then the semiconductor laser device is prevented from outputting optical power

Engineering Contradiction:

Improveoptical power outputVSAvoidend face degradation

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

By segmenting the active layer into multiple ridge stripes with separation sections, the patent ensures that degradation affecting one ridge stripe does not propagate to other ridge stripes. This segmentation creates isolated failure zones, preserving optical power output from non-degraded ridge stripes even when some portions are degraded

Inventive Principle:

Principle #1Segmentation

3Reliability

If multiple ridge stripes are formed with separation sections, then degradation spread is prevented, but device structure becomes more complex

Engineering Contradiction:

Improvedegradation resistanceVSAvoidstructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The active layer is segmented into multiple ridge stripes with separation sections between them. This segmentation prevents degradation spread while maintaining a relatively simple overall structure that can be fabricated using standard semiconductor processing techniques

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Separation sections act as intermediary structures between adjacent ridge stripes. These separation sections physically isolate the ridge stripes, preventing degradation propagation while being integrated into the overall device structure without adding significant complexity

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8855161B2Semiconductor laser device, method of manufacturing semiconductor laser device, and semiconductor laser array

Publication Date: 2014.10.07 MITSUBISHI ELECTRIC CORP

AI summary

A semiconductor laser device includes a substrate, ridge stripes on the substrate and separated by separation sections, a top surface electrode continuously extending over the ridge stripes, and a bottom surface electrode on a bottom surface of the substrate. Each of the ridge stripes includes a lower cladding layer on the substrate, an active layer on the lower cladding layer, an upper cladding layer on the active layer, and a contact layer on the upper cladding layer.