Photonic Integrated Transceiver With SOAs for Independent Optical Power
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Solution Overview
Problem
Optical transceivers with shared lasers face challenges in optimizing both transmit and local oscillator power, leading to suboptimal performance due to tradeoffs between signal-to-noise ratio and sensitivity, which are not simultaneously optimal.
Innovation Solution
A photonic integrated circuit with semiconductor optical amplifiers (SOAs) in both the transmitter and receiver portions, allowing for independent control and optimization of optical signal power, enabling higher signal-to-noise ratio and improved sensitivity by amplifying the local oscillator power and modulated optical signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a shared laser is used to supply both transmitter and receiver portions, then the size of the transceiver is reduced and electrical power is reduced, but the transmit optical power and local oscillator power cannot be independently optimized
Solution Approach 1:
The patent segments the optical path by introducing separate semiconductor optical amplifiers (SOAs) for the transmitter portion and receiver portion, each with independent control. This allows the shared laser output to be independently amplified to optimal power levels for both transmit and local oscillator functions, resolving the contradiction between size reduction and independent power optimization.
2Device complexity
If tradeoffs are made between transmit and local oscillator power to accommodate a shared laser, then device complexity is reduced, but neither transmit nor local oscillator power can be optimal
Solution Approach 1:
The patent introduces semiconductor optical amplifiers as intermediary devices between the shared laser and the transmitter/receiver portions. These SOAs act as mediators that can independently adjust and optimize the optical power for each path, allowing both transmit and local oscillator powers to be optimal while still using a shared laser configuration.
3Reliability
If semiconductor optical amplifiers are added to both transmitter and receiver portions, then signal-to-noise ratio and sensitivity are improved, but device complexity increases
Solution Approach 1:
The patent employs semiconductor optical amplifiers that serve multiple functions: they amplify the optical signal, provide independent power control, and can be integrated into the existing photonic integrated circuit architecture. This multi-functionality allows for improved signal-to-noise ratio and sensitivity while minimizing the increase in device complexity through efficient component utilization.
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 enhances the signal-to-noise ratio and sensitivity of the optical transceiver, allowing for optimized performance beyond the power limits of the laser, while maintaining high optical power throughout the circuit and reducing the need for additional spectral filtering.
Implementation Method 1
A first semiconductor optical amplifier is provided in the transmitter portion, such that an output of the transmitter portion is greater than an output of the transmitter portion in an absence of the first semiconductor optical amplifier
Implementation Method 2
A second semiconductor optical amplifier or variable optical attenuator is provided in the receiver portion to adjust a power of an optical input to the photodiode circuit
Data Source
AI summary
Consistent with the present disclosure, a transceiver is implemented as a photonic integrated circuit (PIC) that includes a transmitter and a receiver. A laser is also provided that provides light to a splitter, which supplies a first portion of the light to the transmitter and a second power of the light to the receiver. Semiconductor optical amplifiers (SOAs) are provided at one or more locations on the PIC. In one example, at least one SOA is provided in the transmitter so that the transmitted optical signal has a desired power, and at least another SOA is provided in the receiver so that the local oscillator signal has a desired power. In a further example, an SOA is provided in the receiver to boost the power of the received optical signal. Preferably, the transceiver, including the SOAs, is monolithically integrated on a substrate, such as a substrate including indium phosphide (InP). Moreover, the SOA can be readily controlled via a low voltage current source consuming minimal electrical power.