Etched Laser Facet Coating for Perpendicular Optical Coupling

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Solution Overview

Problem

Existing semiconductor lasers are sensitive to reflections that can cause undesirable effects such as amplitude noise and linewidth broadening due to light propagating back into the resonant cavity, and current fabrication techniques struggle with depositing uniform coatings on vertical edges of photonic dies.

Innovation Solution

The method involves etching a guiding layer to form a first facet and depositing coatings on it, followed by singulating a substrate to create a second angled facet, using silicon-based materials and standard fabrication tools to achieve controlled deposition on vertical edges, and employing pocket wafers to facilitate processing of photonic dies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If light is emitted from the semiconductor laser device, then optical output is achieved, but reflections propagate back into the resonant cavity causing amplitude noise and linewidth broadening

Engineering Contradiction:

Improveoptical output emissionVSAvoidreflections causing amplitude noise and linewidth broadening

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful reflected light into a beneficial effect by using the reflections to form a distributed feedback mirror. The reflected light waves interfere constructively at specific wavelengths to create high reflectivity, while destructive interference suppresses reflections at other wavelengths. This transforms the harmful back-propagating reflections into a controlled feedback mechanism that stabilizes the laser output and reduces noise.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the refractive index parameter by introducing a dielectric layer with different refractive index than the surrounding materials. This refractive index contrast creates the necessary optical feedback mechanism. By controlling the thickness and refractive index of the dielectric layer, the patent optimizes the feedback strength to achieve stable single-mode operation while minimizing harmful reflections.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If standard fabrication techniques are used to deposit coatings on vertical edges, then manufacturing process is simple, but uniform coating deposition is difficult to achieve

Engineering Contradiction:

Improvecoating deposition processVSAvoiduniformity of coating on vertical edges

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by forming the dielectric layer at a specific stage in the fabrication process, before final device assembly. This timing allows the coating to be deposited on freshly etched vertical surfaces when they are most accessible and uniform. The preliminary formation of this layer also serves as a foundation for subsequent processing steps, ensuring consistent results across multiple manufacturing batches.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If dicing angle is coupled with laser facet angle, then fabrication is simplified, but packaging and coupling to optical fibers or lenses becomes difficult

Engineering Contradiction:

Improvefabrication processVSAvoidpackaging and coupling to optical fibers

Core Design Contradiction:

Ease of manufactureVSEase of operation

Solution Approach 1:

The patent segments the fabrication process into independent stages: first forming the laser cavity with its specific facet angle, then separately forming the dielectric layer at a different orientation. This segmentation allows each component to be optimized independently - the laser facet for optimal optical output and the dielectric layer for optimal feedback - without being constrained by a single dicing angle. The decoupling enables flexible packaging and coupling to various optical components.

Inventive Principle:

Principle #1Segmentation

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 allows for easier packaging and coupling to optical fibers or lenses by decoupling the dicing angle from the laser facet angle, providing repeatable and cost-effective highly reflective and antireflective coatings on vertical edges, enhancing performance and reducing reflections.

Implementation Method 1

a dielectric layer at a second facet of the waveguide, the dielectric layer to reflect a portion of the emitted light

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

decoupling the dicing angle from the laser facet angle of a semiconductor laser device, it is possible to choose a relatively large incident angle and still have the refractive light coming out substantially perpendicular to the substrate facet

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS20260074482A1Wafer-level etched facet for perpendicular coupling of light from a semiconductor laser device

Publication Date: 2026.03.12 SKORPIOS TECHNOLOGIES INC

AI summary

A semiconductor laser device is provided. The semiconductor laser device includes: a substrate having a first facet; a guiding layer having a second facet through which an output light is configured to be emitted; a bottom dielectric layer between the substrate and the guiding layer, and a top dielectric layer on the guiding layer. The second facet is at an angle relative to the first facet.