Semiconductor Laser Light Window Segmentation for Absorption Control

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Solution Overview

Problem

The degradation of semiconductor lasers due to light absorption leads to decreased light emission efficiency, and while a wide window structure region can inhibit degradation, it increases free carrier absorption, further reducing efficiency.

Innovation Solution

A semiconductor laser design featuring a waveguide with a narrow width and a light window structure region of greater width, formed continuously or intermittently along the end faces, which inhibits light absorption and reduces free carrier absorption, thereby maintaining light emission efficiency and preventing device degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the window structure region is set in a wide range to inhibit degradation due to light absorption, then device degradation is reduced, but free carrier absorption increases which decreases light emission efficiency

Engineering Contradiction:

Improvedevice degradation resistanceVSAvoidfree carrier absorption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The window structure region is divided into multiple segments: a first window structure region with a first width and a second window structure region with a second width greater than the first width. This segmentation allows different portions to serve different functions - the first region provides degradation resistance while the second region minimizes free carrier absorption, thereby resolving the contradiction between reliability and energy loss.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different widths are assigned to different regions of the window structure. The first window structure region has a narrower width optimized for preventing degradation, while the second window structure region has a wider width optimized for reducing free carrier absorption. This local differentiation allows each region to perform its specific function optimally, resolving the contradiction between degradation resistance and energy efficiency.

Inventive Principle:

Principle #3Local quality

2Loss of energy

If a narrow waveguide width is used to reduce free carrier absorption, then light emission efficiency is maintained, but light absorption in the vertical region increases leading to device degradation

Engineering Contradiction:

Improvefree carrier absorptionVSAvoiddevice degradation resistance

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The waveguide structure is segmented into a first window structure region and a second window structure region with different widths. This segmentation enables the first region to protect against degradation while the second region minimizes free carrier absorption, resolving the contradiction between reliability and energy loss.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different width characteristics are applied locally to different regions. The first window structure region employs a narrower width for degradation protection, while the second window structure region employs a wider width for reduced free carrier absorption, thereby resolving the contradiction between device reliability and energy efficiency.

Inventive Principle:

Principle #3Local quality

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 described design effectively inhibits the decrease in light emission efficiency and semiconductor laser degradation by minimizing light absorption and leak current, enhancing the overall performance of the device.

Implementation Method 1

the light absorption in a region extending in the vertical direction from the semiconductor layer, in particular, the ridge waveguide can be inhibited

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

absorption of free carriers can be inhibited and a decrease in light emission efficiency can be inhibited

Methodology Applied

Scientific EffectFree carrier absorption: Absorption (EM radiation)

Data Source

PatentUS11245248B2Semiconductor laser

Publication Date: 2022.02.08 SONY SEMICON SOLUTIONS CORP

AI summary

A semiconductor laser includes a semiconductor layer including end faces and at least one of the end faces is configured as a light emission end face. The semiconductor layer includes a waveguide and a light window structure region. The waveguide has a first width and is extended between the end faces. The light window structure region includes an opening having a second width greater than the first width arranged along the waveguide and is formed continuously or intermittently from one to another of the end faces.