Semiconductor Laser Array Common Anode n-MOSFET Control

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Solution Overview

Problem

Conventional semiconductor laser arrays face challenges with high power dissipation, short switching times, and high control voltage requirements due to large parasitic inductances and capacitances, as well as high costs and geometric dimensions, particularly when using p-MOSFETs, which limit the feasibility of control with shorter current pulses and result in unfavorable control pulse forms and widths.

Innovation Solution

A semiconductor laser array with a common anode and a reverse layer sequence, where the p-doped layers face the substrate and the n-doped layers face the surface, allowing for improved control via n-MOSFETs with a source circuit providing voltage and current gain greater than one, reducing space and weight, and enabling lower control voltage and shorter switching times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If p-MOSFETs are used in the control circuit, then voltage and current gain greater than one is achieved, but power dissipation increases and switching times become longer

Engineering Contradiction:

Improvevoltage and current gainVSAvoidpower dissipation

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent inverts the conventional control approach by using n-MOSFETs with a drain circuit instead of p-MOSFETs with a source circuit. This inversion allows achieving the required voltage and current gain through the circuit configuration rather than relying solely on p-MOSFET characteristics, thereby reducing power dissipation while maintaining control effectiveness.

Inventive Principle:

Principle #13The other way round (Inversion)

2Power

If p-MOSFETs are used in the control circuit, then voltage and current gain greater than one is achieved, but acquisition costs increase

Engineering Contradiction:

Improvevoltage and current gainVSAvoidacquisition costs

Core Design Contradiction:

PowerVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #13The other way round (Inversion)

3Power

If p-MOSFETs are used in the control circuit, then voltage and current gain greater than one is achieved, but geometric dimensions and weight increase

Engineering Contradiction:

Improvevoltage and current gainVSAvoidgeometric dimensions and weight

Core Design Contradiction:

PowerVSWeight of moving object

Solution Approach 1:

Inventive Principle:

Principle #13The other way round (Inversion)

4Ease of operation

If long wire connections are used in the circuit, then circuit connectivity is achieved, but parasitic inductances and capacitances increase

Engineering Contradiction:

Improvecircuit connectivityVSAvoidparasitic inductances and capacitances

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies segmentation by dividing the control circuit into modular units with localized connections. Each laser module has its control circuit closely integrated, minimizing wire lengths and reducing parasitic inductances and capacitances while maintaining full circuit connectivity and control functionality.

Inventive Principle:

Principle #1Segmentation

5Ease of operation

If high control voltage is applied, then transistor control is achieved, but control pulse form and width become unfavorable

Engineering Contradiction:

Improvetransistor controlVSAvoidcontrol pulse form and width

Core Design Contradiction:

Ease of operationVSDuration of action of moving object

Solution Approach 1:

The patent changes the control voltage parameter from high to low by using n-MOSFETs with a drain circuit configuration. This parameter change enables effective transistor control while producing favorable control pulse forms and widths, as the circuit provides the necessary voltage and current gain through its structure rather than requiring high input voltage.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11228161B2Semiconductor laser array and semiconductor laser array circuit arrangement

Publication Date: 2022.01.18 AMS OSRAM INT GMBH

AI summary

A semiconductor laser array may include a plurality of semiconductor lasers and a common substrate configured as a common anode of said plurality of semiconductor lasers. Each semiconductor laser may have a pn junction region between the common anode and a cathode contact layer. The pn junction region may include a p-doped layer and an n-doped layer. The p-doped layer of the pn junction region may face the substrate. The semiconductor laser array circuit arrangement may include a semiconductor laser array, each laser may be controlled by a driver with an n-MOSFET.