Double Array Dielectric Cylinders for Harmonic Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for generating higher harmonics of light, such as using optically non-linear crystals, face limitations in conversion efficiency and require precise phase matching and beam focusing, which are technically challenging and often result in low conversion rates.
Innovation Solution
A double array of sub-wavelength dielectric cylinders is used to enhance local field amplification through resonant scattering, eliminating the need for phase matching and beam focusing, and achieving high conversion efficiency by optimizing the distance between the arrays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional optically non-linear crystals are used for harmonic generation, then phase matching and beam focusing are required, but this increases device complexity and reduces conversion efficiency
Solution Approach 1:
The invention divides the harmonic generation process into discrete resonant scattering events at sub-wavelength dielectric cylinders, eliminating the need for continuous phase matching along a crystal slab. Each cylinder acts as an independent resonant scatterer, converting incident light to second harmonics through localized field enhancement.
Solution Approach 2:
The invention replaces the mechanical/optical system of beam focusing and phase matching with a resonant scattering mechanism at sub-wavelength structures. The dielectric cylinders create localized resonant fields that naturally enhance the nonlinear optical response without requiring external focusing optics or phase matching control.
2Productivity
If conventional crystal slabs are used, then conversion rate can be achieved, but the active length is large requiring miniaturization
Solution Approach 1:
The invention transitions from a one-dimensional crystal slab (millimeter to centimeter scale) to a zero-dimensional sub-wavelength cylinder structure. The harmonic generation occurs at the resonant frequency of individual cylinders with dimensions much smaller than the wavelength, enabling miniaturization while maintaining conversion efficiency through resonant field enhancement.
3Productivity
If conventional methods are used for harmonic generation, then second harmonic can be produced, but conversion efficiency is low and requires precise phase matching
Solution Approach 1:
The invention changes the fundamental parameter of the optical structure from a continuous crystal slab to discrete sub-wavelength dielectric cylinders. This parameter change enables resonant scattering at the cylinder dimensions, creating localized field enhancement that naturally enhances the nonlinear optical response without requiring precise phase matching control.
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 achieves a conversion rate of up to 44% of the incident flux into second harmonics, comparable to traditional methods, but at a significantly reduced active length, enabling miniaturization and efficient frequency conversion of lower power light beams.
Implementation Method 1
enhance local field amplification through resonant scattering
Implementation Method 2
generation of higher harmonics of monochromatic electromagnetic radiation
Data Source
AI summary
Various methods and systems are provided for generation of higher harmonics of monochromatic electromagnetic radiation. In one embodiment, among others, a system includes a double array of planar structures including a first periodically structured planar structure having a periodic spacing corresponding to a resonant frequency and a second periodically structured planar structure in parallel with the first structure. The system also includes a source configured to illuminate the first structure with a beam of monochromatic electromagnetic radiation at the resonant frequency to produce a higher harmonic of the monochromatic electromagnetic radiation. In another embodiment, a method includes directing a beam of monochromatic electromagnetic radiation at a resonant frequency at a double array of planar structures and generating a higher harmonic of the monochromatic electromagnetic radiation. The double array includes a first periodically structured planar structure and a second periodically structured planar structure in parallel with the first structure.