Prism-Isolator PIC Assembly for Laser Back-Reflection Isolation

Solution Overview

Problem

The lack of an on-chip optical isolator in photonic integrated circuits (PICs) leads to separate laser sources and PICs connected by optical fibers and connectors, resulting in large physical size and high cost.

Innovation Solution

Integration of a 90° retroreflector prism and optical isolators within the PIC, eliminating the need for fibers and connectors, and providing isolation for the laser source, thus enabling a compact and cost-effective design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate laser sources and PICs are used with optical fibers and connectors, then laser isolation can be achieved, but the physical size and cost increase

Engineering Contradiction:

Improvelaser isolationVSAvoidpackaging footprint

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent combines the optical isolator with the photonic integrated circuit substrate, integrating previously separate components (laser source, PIC, and optical isolator) into a single monolithic structure. This merging eliminates the need for external optical fibers and connectors, thereby reducing packaging footprint while maintaining laser isolation functionality through on-chip integration.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If separate laser sources and PICs are used with optical fibers and connectors, then laser isolation can be achieved, but the cost increases

Engineering Contradiction:

Improvelaser isolationVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines the optical isolator with the photonic integrated circuit substrate, integrating previously separate components (laser source, PIC, and optical isolator) into a single monolithic structure. This merging eliminates the need for external optical fibers and connectors, thereby reducing packaging footprint while maintaining laser isolation functionality through on-chip integration.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If separate laser sources and PICs are used, then laser isolation can be achieved, but alignment complexity increases

Engineering Contradiction:

Improvelaser isolationVSAvoidalignment complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the optical isolator with the photonic integrated circuit substrate, integrating previously separate components (laser source, PIC, and optical isolator) into a single monolithic structure. This merging eliminates the need for external optical fibers and connectors, thereby reducing packaging footprint while maintaining laser isolation functionality through on-chip integration.

Inventive Principle:

Principle #5Merging (Combining)

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 integration reduces packaging footprint and cost while maintaining laser performance by blocking back reflections, simplifying alignment processes, and enabling a monolithic photonic chip with integrated optical circuitry.

Implementation Method 1

an optical isolator is present to block reflection from the PIC from reaching the laser

Methodology Applied

Scientific EffectOptical isolation: Absorption (EM radiation)

Implementation Method 2

a 90° retroreflector prism and optical isolators within the PIC

Methodology Applied

Scientific EffectRetroreflection: Retroreflector

Implementation Method 3

a prism assembly having a prism and at least one isolator

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS12449605B2System, apparatus and method for integrating laser and optical circuitry on a photonics integrated circuit using an assembly having a prism and isolator

Publication Date: 2025.10.21 INTEL CORP

AI summary

In one embodiment, a package includes: a substrate; a photonic integrated circuit (PIC) adapted to the substrate, the PIC including at least one optical circuit, a first plurality of waveguides, a second plurality of waveguides, and a laser to output optical energy via the first plurality of waveguides; and a prism assembly adapted to the substrate to reflect the optical energy output from the first plurality of waveguides to the second plurality of waveguides, the prism assembly including a prism and at least one isolator. Other embodiments are described and claimed.