Integrated Optoelectronic Device with Resistive Heater
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated electro-absorption modulators (EAMs) face a trade-off between high-speed operation and temperature stability due to the difficulty in simultaneously minimizing series resistance and locally regulating temperature, as placing a heater alongside the diode mesa interferes with electrical contact placement.
Innovation Solution
The optoelectronic devices incorporate a heterogeneous waveguide structure with a diode structure that allows direct resistive heating by applying a DC heater bias voltage between electrically conductive vias contacting the doped bottom layer, or by heating the waveguide to spread heat to the diode, enabling separate circuits for heating and modulation, thus avoiding the need for a separate heater.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heater is placed alongside the diode mesa to regulate temperature, then temperature stability is improved, but series resistance increases due to interference with electrical contact placement
Solution Approach 1:
The patent merges the heater function with the existing electrical contact structure by using the same vias and contact regions to serve dual purposes: electrical connection and resistive heating. This eliminates the need for separate heater placement and resolves the spatial conflict between heater and electrical contact.
Solution Approach 2:
The electrical contact vias and contact regions are designed to perform multiple functions simultaneously: providing electrical connection to reduce series resistance and generating heat through resistive heating for temperature stabilization. This multi-functionality eliminates the trade-off between the two requirements.
2Speed
If electrical contacts are placed on both sides of the diode mesa to minimize series resistance, then device speed is improved, but temperature regulation becomes difficult
Solution Approach 1:
The patent combines temperature regulation capability into the existing electrical contact structure, allowing both sides of the diode mesa to serve as both electrical contacts and heating elements. This maintains the high-speed performance while enabling temperature regulation.
Solution Approach 2:
The electrical contact structure itself generates the heat needed for temperature regulation through its own electrical resistance when current flows through it during modulation operation. The system uses its own operating current to provide self-heating for temperature stabilization.
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 simplifies fabrication, improves thermal efficiency, and allows for active temperature regulation without compromising device speed, enabling stable operation within a narrower temperature range.
Implementation Method 1
applying a DC heater bias voltage between electrically conductive vias both contacting the doped bottom layer, but on opposite sides of the diode, causing an electrical current to flow across and resistively heat the doped bottom layer
Implementation Method 2
heating the waveguide to spread heat to the diode
Implementation Method 3
EAMs generally operate based on the Franz-Keldysh effect, that is, a change in the absorption spectrum of a semiconductor via a change in the bandgap energy as caused by an applied electric field
Implementation Method 4
the intrinsic-type layer of the diode mesa includes a quantum well structure to exploit the quantum-confined Stark effect for high extinction ratios
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
Disclosed are structures as well as methods of manufacture and operation of integrated optoelectronic devices that facilitate directly heating the diode or waveguide structures to regulate a temperature of the device while allowing electrical contacts to be placed close to the device to reduce the electrical resistance. Embodiments include, in particular, heterogeneous electro-absorption modulators that include a compound-semiconductor diode structure placed above a waveguide formed in the device layer of an SOI substrate.