Planar Lightwave Circuit Optical Transceiver for High-Density Bidirectional Transmission
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Solution Overview
Problem
Current optical transceivers, particularly in duplex and BIDI types, face challenges in achieving high-speed and high-density bidirectional optical transmission and reception due to separate optical transmission and reception interfaces, which limit coupling efficiency and integration density.
Innovation Solution
The optical transceiver incorporates a planar lightwave circuit, arrayed waveguide grating, and spot size converters on a single chip, along with mirrors and mounts, to linearize optical axes and enhance coupling efficiency, and includes laser diodes and photodiodes connected via high-speed signal lines for bidirectional operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate optical transmission and reception interfaces are used (duplex type), then optical transmission and reception can be performed independently, but coupling efficiency decreases and integration density is limited
Solution Approach 1:
The patent merges the optical transmission and reception interfaces into a single integrated optical transceiver unit. The planar lightwave circuit integrates multiple optical components including waveguides, couplers, and photodetectors on a single chip, allowing both transmission and reception functions to be combined in one device, thereby improving integration density while maintaining functional independence through separate optical paths
2Reliability
If separate optical transmission and reception interfaces are used (duplex type), then optical transmission and reception can be performed independently, but coupling efficiency decreases
Solution Approach 1:
The patent introduces an optical coupler as an intermediary component within the planar lightwave circuit that efficiently couples optical signals between different waveguides and components. This coupler uses evanescent field coupling to transfer optical energy with high efficiency between adjacent waveguides, resolving the coupling efficiency issue while maintaining separate transmission and reception paths
3Device complexity
If integrated components are used on a single chip, then coupling efficiency and integration density improve, but heat management becomes more challenging
Solution Approach 1:
The patent extracts the heat generation issue from the integrated optical chip by using separate mount structures for the laser diode and photodetector. These mounts are positioned away from the main planar lightwave circuit chip, allowing heat to be dissipated independently through dedicated thermal paths rather than being trapped within the integrated circuit, thus managing heat effectively while maintaining high integration density
4Adaptability or versatility
If bidirectional operation is implemented, then optical transmission and reception can occur through the same port, but wavelength separation and signal isolation become more difficult
Solution Approach 1:
The patent segments the optical spectrum into distinct wavelength channels using wavelength division multiplexing (WDM). The planar lightwave circuit includes wavelength-specific waveguides and filters that separate incoming and outgoing optical signals by their wavelengths, allowing bidirectional communication through the same physical port while maintaining signal isolation through spectral separation
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 configuration enables high-speed, high-density bidirectional optical transmission and reception by improving coupling efficiency and integrating components for efficient heat management and signal processing, optimizing performance in optical transceivers.
Implementation Method 1
an arrayed waveguide grating connected to the first planar lightwave circuit
Implementation Method 2
a first spot size converter connecting the optical receptacle and the first planar lightwave circuit
Implementation Method 3
a mirror configured to change a path of an optical output of the arrayed waveguide grating. The mirror may be a 45-degree mirror
Implementation Method 4
a laser diode connected to the second spot size converter, and a laser diode driver
Implementation Method 5
a photodiode connected to the third planar lightwave circuit, and a trans-impedance amplifier (TIA) connected to the photodiode
Data Source
AI summary
An optical transceiver may include an optical receptacle configured to input or output an optical signal, a first planar lightwave circuit through which the optical signal travels, an arrayed waveguide grating connected to the first planar lightwave circuit, and a first spot size converter connecting the optical receptacle and the first planar lightwave circuit.