Photonic Band Gap Crystal Dynamic Frequency Control via Acoustic Modulation
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Solution Overview
Problem
Dynamic frequency control of photonic band gap crystals has been elusive, as existing technologies lack efficient and cost-effective methods to alter their transmission properties in real-time.
Innovation Solution
Embedding a photonic band gap crystal within a defect cavity of an acoustic band gap crystal, where acoustic waves can modify the photonic crystal's lattice constant, symmetry, and refractive index contrast, allowing for real-time control of transmission properties through the generation of acoustic waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If photonic band gap crystal is used for filtering electromagnetic radiation, then wavelength selection is achieved, but dynamic frequency control is difficult to implement
Solution Approach 1:
The photonic band gap crystal is embedded within a defect cavity of an acoustic band gap crystal, creating a nested structure where the acoustic crystal contains the photonic crystal. This nesting allows the acoustic waves to directly interact with and modulate the photonic crystal's properties, enabling dynamic frequency control without complex external control systems.
Solution Approach 2:
Acoustic waves serve as an intermediary mechanism to control the photonic crystal's transmission properties. By generating acoustic waves at specific frequencies, the lattice constant and refractive index of the photonic crystal are modulated, which in turn controls the transmission of electromagnetic radiation. This intermediary approach simplifies the control mechanism compared to direct electrical or mechanical control of the photonic crystal.
2Productivity
If acoustic waves are used to modulate photonic crystal properties, then real-time control of transmission properties is achieved, but manufacturing precision requirements increase
Solution Approach 1:
The defect cavity in the acoustic band gap crystal is specifically designed with local quality variations to create a resonant structure that can effectively couple with the photonic crystal. This localized modification allows for efficient acoustic wave generation and focusing on the photonic crystal, improving control effectiveness while reducing overall manufacturing complexity.
3Adaptability or versatility
If photonic crystal lattice constant is changed to control transmission, then wavelength range is adjusted, but structural stability may be compromised
Solution Approach 1:
Acoustic waves provide periodic modulation of the photonic crystal lattice, causing oscillations in the lattice constant at the acoustic frequency. This periodic action allows dynamic adjustment of the transmission wavelength range while maintaining the overall structural stability of the photonic crystal, as the lattice returns to its equilibrium position after each oscillation cycle.
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 enables efficient and inexpensive control of photonic signal parameters, including the range of transmissible wavelengths, allowing for selective passing or blocking of electromagnetic radiation, and real-time modulation of band gap characteristics.
Implementation Method 1
Acoustic waves in the acoustic crystal squeeze the photonic band gap crystal to change its properties, particularly one or more of lattice constant, symmetry, and optical refractive index contrast
Implementation Method 2
acoustic waves in the acoustic crystal can alter transmission properties of the photonic crystal to modulate the transmission of electromagnetic radiation through the photonic crystal
Implementation Method 3
Photonic band gap crystals, referred to as photonic band crystals (PBCs) or simply photonic crystals, are characterized by materials with different refractive indices generally periodically spaced in one or more dimensions. The periodic structure and the properties of the selected materials creates a band gap, a range of wavelengths of electromagnetic radiation that are reflected and cannot pass through the photonic crystal
Data Source
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AI summary
An apparatus (10) and method for dynamic frequency control of a photonic band gap crystal includes an acoustic band gap crystal (12) having a defect site (14), a photonic band gap crystal (20) in the defect site of the acoustic band gap crystal (12), and a sound wave generator (40) coupled to the acoustic band gap crystal (12). Consequently, acoustic waves in the acoustic band gap crystal (12) can be used to controllably alter transmission properties of the photonic band gap crystal (20) and thereby modulate the transmission of electromagnetic radiation through the photonic band gap crystal (20). Acoustic waves in the acoustic band gap crystal (12) can squeeze the photonic band gap crystal (20) to change its properties, including one or more of lattice constant, symmetry, and optical refractive index contrast.