Programmable Optical Filters on Piezoelectric Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical FIR and IIR filters lack the ability to accommodate varying bit rates in optical communications, as they are not programmable and primarily rely on silicon substrates, limiting their adaptability and efficiency in high-speed signal processing.
Innovation Solution
The development of optical IIR and FIR filters with programmable parameters, utilizing a piezoelectric substrate like Lithium Niobate for variable delays and individually addressable attenuators, allowing for adjustable phase and amplitude control through a control bus, enabling the filters to accommodate varying bit rates by dynamically altering delay values and tap weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If optical filters are implemented on silicon substrates with fixed parameters, then manufacturing is simplified, but adaptability to varying bit rates is limited
Solution Approach 1:
The patent implements variable delay lines with electrically controllable delay values, allowing the filter to dynamically adjust its parameters. The delay values can be programmed to match different bit rates, transforming a static filter into an adaptive system that maintains optimal performance across varying communication speeds without requiring multiple fixed designs.
Solution Approach 2:
The patent employs individually addressable attenuators that can electrically adjust attenuation values for each tap in the filter. By changing the attenuation parameters dynamically, the filter adapts to different bit rates and signal conditions, eliminating the need for multiple fixed-parameter filter designs and reducing overall system complexity.
2Productivity
If fixed delay values are used in optical filters, then device complexity is reduced, but productivity in handling varying bit rates decreases
Solution Approach 1:
The patent creates a universal optical filter design that can handle multiple bit rates through programmable delay values and attenuators. A single filter structure performs the function of multiple fixed filters by electrically reconfiguring its parameters, improving productivity across different communication standards while avoiding the complexity of implementing separate filters for each bit rate.
Solution Approach 2:
The patent replaces physical reconfiguration mechanisms with electrical control signals. Instead of mechanically changing filter components to adapt to different bit rates, the system uses electronically controllable delay lines and attenuators that can be programmed remotely, reducing mechanical complexity while enhancing signal processing efficiency for varying bit rates.
3Adaptability or versatility
If programmable parameters are implemented in optical filters, then adaptability to varying bit rates is improved, but device complexity increases
Solution Approach 1:
The patent divides the filter into individually addressable segments, where each tap has its own controllable attenuator. This segmentation allows independent control of each filter coefficient, enabling precise adaptation to different bit rates while maintaining a modular architecture that manages complexity through systematic organization of control elements.
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
Enables efficient signal processing in the optical domain by allowing for electrically configurable filter coefficients, accommodating a wide range of bit rates without requiring changes to the filter design, thus enhancing the adaptability and performance of optical filters in high-speed communications.
Implementation Method 1
the variable delay of each input filter tap and each output filter tap is implemented on a piezoelectric substrate, the optical infinite impulse response filter further including a control input coupled to the piezoelectric substrate and configured to receive a control voltage that controls an amount of phase delay provided by the piezoelectric substrate
Data Source
AI summary
Aspects and examples are directed to programmable optical finite impulse response filters and optical infinite impulse response filters, which may be implemented as photonic integrated circuits.