Bidirectional EML Chiplets for Dense Co-Packaged Optics
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Solution Overview
Problem
There is a need for improved Indium Phosphide (InP)-based electro-photonic receiver and transmitter modules and solutions for co-packaging these modules with silicon electronics, particularly in terms of cost, energy efficiency, and reduced port-to-port spacing for high-density fiber arrays.
Innovation Solution
The development of electro-photonic integrated circuits capable of bidirectional operation using an electro-absorption modulated laser (EML) with control circuitry that allows independent operation in transmitter and receiver modes, integrated with silicon electronics, utilizing InP-based semiconductor materials for compact design and efficient vertical optical coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional separate packaging of optical modules and silicon electronics is used, then ease of manufacture and reliability are maintained, but device size increases and port-to-port spacing is larger
Solution Approach 1:
The patent merges optical modules and silicon electronics into a single co-packaged unit, integrating the electro-absorption modulated laser, EAM, and silicon electronic circuits on the same substrate. This combination reduces the overall device volume and port-to-port spacing while maintaining functional reliability through unified thermal and electrical management structures.
Solution Approach 2:
The patent implements a nested arrangement where the electro-absorption modulated laser and EAM are vertically stacked with silicon electronics beneath them. The optical waveguides are embedded within the substrate structure, creating a multi-layer nested configuration that maximizes space utilization and reduces the footprint while maintaining signal integrity.
2Use of energy by moving object
If InP-based electro-photonic modules are co-packaged with silicon electronics, then energy efficiency and port-to-port spacing are improved, but manufacturing complexity increases
Solution Approach 1:
The patent changes the material parameter from traditional silicon-only construction to an hybrid InP-silicon structure. The InP-based electro-absorption modulated laser and EAM provide superior optical modulation efficiency and lower power consumption compared to conventional silicon photonics, while the co-packaging architecture enables these energy-efficient components to be integrated with standard silicon electronic circuits.
3Adaptability or versatility
If bidirectional operation of EML is implemented, then device versatility is improved, but control circuitry complexity increases
Solution Approach 1:
The patent implements a universal electro-absorption modulated laser structure that can operate in both transmitter and receiver modes through controlled biasing. The same physical device serves dual functions: as a transmitter when forward-biased to emit modulated light, and as a receiver when reverse-biased to detect incoming optical signals, eliminating the need for separate transmit and receive laser modules.
Solution Approach 2:
The patent employs dynamic bias control to switch the EML between transmit and receive modes. The control circuitry adjusts the bias voltage applied to the EML in real-time based on operational requirements, enabling rapid mode switching and bidirectional communication without physical reconfiguration or additional components.
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 solution enables efficient co-packaging of electro-photonic modules with silicon electronics, achieving high-speed, low-power, and compact form factor, suitable for high-density optical interconnects with improved energy efficiency and reduced port-to-port spacing.
Implementation Method 1
an electro-absorption modulated laser (EML), the EML comprising a laser and an electro-absorption modulator (EAM)
Implementation Method 2
in the receiver mode, the second part of the EAM is operable as a photodiode receiver to receive an optical input and output a photocurrent to the TIA
Data Source
AI summary
Electro-photonic integrated circuits comprising optical transmitters and receivers are disclosed, wherein a monolithically integrated electro-absorption modulated laser (EML) is operable bidirectionally, in a transmitter mode and in a receiver mode. Vertically stacked waveguides are provided for a laser and an electro-absorption modulator (EAM). The laser and EAM are optically coupled using a laterally tapered vertical optical coupler. The EML comprises monolithically integrated electronic circuitry, e.g., driver and control electronics for the driving the laser and EAM as an EML, in transmitter mode. The electronic circuitry comprises a transimpedance amplifier (TIA). The EAM has first and second parts that can be independently biased. In receiver mode, the laser current is reduced to close to the threshold, and a first part of the EAM is biased to absorb residual laser light, and the second part of the EAM acts as a photodiode receiver to provide a photocurrent to the TIA.