Integrated Circuit Spectrometer With Microring Filter Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing miniaturized spectrometers face challenges in achieving high performance due to the need for long optical paths and moving parts, which limit miniaturization and robustness, and suffer from trade-offs between resolution and bandwidth, making it difficult to scale up to broader spectral ranges.
Innovation Solution
An integrated circuit spectrometer using a photonic circuit with a filter array of microring resonators and detectors, coupled with an artificial neural network for spectrum reconstruction, allowing for high-resolution spectral analysis without the need for tuning or moving parts, and enabling broadband operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If long optical paths are used to achieve high spectral resolution, then measurement precision is improved, but device volume increases and miniaturization is limited
Solution Approach 1:
The optical path is segmented into multiple S-shaped sections that fold back on each other within a compact footprint. This segmentation allows the light to traverse a long effective optical path while maintaining a small device volume, resolving the contradiction between spectral resolution and miniaturization.
Solution Approach 2:
The optical path is extended by utilizing three-dimensional spatial arrangement with S-shaped folding patterns. Instead of a simple linear extension that would increase device volume, the path folds in multiple dimensions (up-down-left-right sequences) to achieve long optical path length within a compact two-dimensional footprint.
2Adaptability or versatility
If movable mirrors are used to achieve optical path variation, then spectral analysis capability is improved, but device complexity increases and robustness to vibrations deteriorates
Solution Approach 1:
Movable mechanical mirrors are replaced with fixed waveguide structures that implement optical path variation through optical interference principles. The S-shaped waveguides create fixed but effective variable optical paths using phase modulation and interference, eliminating mechanical moving parts while maintaining spectral analysis capability and improving vibration robustness.
3Adaptability or versatility
If arrayed waveguide gratings or planar concave gratings are used to increase bandwidth, then spectral range is improved, but device area increases due to trade-off between resolution and channel count
Solution Approach 1:
The system achieves broadband operation by dynamically tuning the resonance wavelengths of microring resonators rather than using fixed grating structures. By changing the operational parameters (resonance wavelengths) of the same compact filter array, the system can cover broad spectral ranges without increasing device area, overcoming the resolution-bandwidth trade-off inherent in grating-based systems.
4Adaptability or versatility
If filter arrays with large free spectral range are used to scale up spectral range, then bandwidth is improved, but manufacturing difficulty increases due to fabrication restrictions
Solution Approach 1:
Instead of relying on large static free spectral ranges that are difficult to fabricate, the system uses dynamically tunable microring resonators. The resonance wavelengths can be adjusted through thermal, electrical, or optical tuning mechanisms, allowing the same compact filter array to achieve broad spectral coverage without requiring large FSR structures that are challenging to manufacture.
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
The proposed solution enables miniaturized spectrometers with high resolution and robustness against vibrations, capable of broadband spectral analysis and efficient spectrum reconstruction, suitable for portable devices and miniaturized sensors.
Implementation Method 1
a filter array of microring resonators in optical communication with the optical input port, each microring resonator being characterized by a different series of resonance wavelengths
Implementation Method 2
a plurality of detectors, each of which is associated with one of said microring resonators to detect photons from an output of the microring resonator
Data Source
AI summary
An integrated circuit spectrometer comprises a photonic circuit comprising: an optical input port for receiving light from a light source: and a filter array of filter elements, such as microring resonators, in optical communication with the optical input port. Each microring resonator is characterized by a different series of resonance wavelengths. If alternative filter elements are used, the filter elements may have different filter peaks to each other. The integrated circuit spectrometer also comprises a plurality of detectors, each of which is associated with one of said microring resonators to detect photons from an output of the microring resonator: and at least one processor configured to reconstruct, from signals received at the detectors, an input spectrum of the light received at the optical input port. The input spectrum may be reconstructed by an artificial neural network.