Distributed Optoelectronic Receiver for High-Data-Rate Links

Solution Overview

Problem

Silicon (Si) waveguide-based photodiodes demonstrate lower responsivity compared to Germanium (Ge) counterparts, leading to higher junction capacitance, which attenuates input bandwidth and reduces optical receiver sensitivity, making them unsuitable for high-data-rate links.

Innovation Solution

The Si photodiode is split into smaller sections, each driving a corresponding gain cell in a distributed transimpedance amplifier implementation, mitigating capacitance effects and enabling broader bandwidth and improved sensitivity by distributing the capacitance and combining responses across individual gain cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Si PD length is increased to compensate for lower responsivity, then responsivity is improved, but junction capacitance increases significantly

Engineering Contradiction:

ImproveresponsivityVSAvoidjunction capacitance

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The photodiode is divided into multiple smaller segments or sections along the waveguide. Each segment generates a photocurrent that is amplified by a corresponding gain cell in the distributed amplifier structure. This segmentation reduces the capacitance burden on any single amplification stage while maintaining overall responsivity through the combined output of multiple segments.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If Si PD length is increased to compensate for lower responsivity, then responsivity is improved, but optical receiver sensitivity decreases

Engineering Contradiction:

ImproveresponsivityVSAvoidoptical receiver sensitivity

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The photodiode is divided into multiple smaller segments or sections along the waveguide. Each segment generates a photocurrent that is amplified by a corresponding gain cell in the distributed amplifier structure. This segmentation reduces the capacitance burden on any single amplification stage while maintaining overall responsivity through the combined output of multiple segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements a distributed amplifier architecture where multiple gain cells are distributed along the photodiode length, each providing local amplification. This dynamic distribution of amplification stages allows the system to handle the total photocurrent from the extended photodiode while maintaining bandwidth and sensitivity, as each gain cell operates on a smaller capacitive load rather than a single lumped amplifier handling the entire capacitance.

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If Si PD length is increased to compensate for lower responsivity, then responsivity is improved, but input bandwidth is attenuated

Engineering Contradiction:

ImproveresponsivityVSAvoidinput bandwidth

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The photodiode is divided into multiple smaller segments or sections along the waveguide. Each segment generates a photocurrent that is amplified by a corresponding gain cell in the distributed amplifier structure. This segmentation reduces the capacitance burden on any single amplification stage while maintaining overall responsivity through the combined output of multiple segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements a distributed amplifier architecture where multiple gain cells are distributed along the photodiode length, each providing local amplification. This dynamic distribution of amplification stages allows the system to handle the total photocurrent from the extended photodiode while maintaining bandwidth and sensitivity, as each gain cell operates on a smaller capacitive load rather than a single lumped amplifier handling the entire capacitance.

Inventive Principle:

Principle #15Dynamics

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 substantially improves receiver sensitivity by reducing the impact of large silicon photodiode capacitance, enhancing bandwidth and group-delay performance, making Si PDs more suitable for high-data-rate optical communication links.

Implementation Method 1

respective PIC sections include a photodiode... Transform Optical Energy to Electrical Energy

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS10606004B2Distributed optoelectronic receiver

Publication Date: 2020.03.31 INTEL CORP

AI summary

Embodiments herein may relate to an optoelectronic receiver that includes a photonic integrated circuit (PIC) coupled with a light source. Respective PIC sections of the PIC may include a photodiode and a junction capacitor. The optoelectronic receiver may further include an electronic integrated circuit (EIC) coupled with the PIC. Respective EIC sections of the EIC may be communicatively coupled to respective ones of the PIC sections. Other embodiments may be described and/or claimed.