Meta-Grating Optical Modulator for High-Speed Beam Steering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical modulating devices face limitations in response time and dispersion due to their driving methods, and there is a need for improved control over light properties in optical systems, particularly in achieving high-speed operation with reduced side lobes and improved signal-to-noise ratio (SNR).
Innovation Solution
An optical modulating device utilizing a meta-grating structure formed by nano-antennas that change the traveling direction of incidence light based on a periodic and discrete driving signal, emitting first-order diffraction light with minimal side lobes, achieved through the adjustment of optical intensity and geometric phase control of nano-antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional optical modulating devices (liquid crystal or MEMS) are used, then light properties can be controlled, but response time is limited and dispersion occurs
Solution Approach 1:
The patent replaces mechanical systems (MEMS moving parts, liquid crystal molecular reorientation) with a meta-grating structure that modulates light through geometric phase control. The meta-grating uses sub-wavelength nano-antennas arranged in a periodic pattern, where the phase of reflected light is controlled by the position of each antenna within the unit cell, enabling high-speed modulation without mechanical movement and eliminating response time dispersion.
Solution Approach 2:
The patent changes the geometric phase parameter of the meta-grating by adjusting the position of nano-antennas within each unit cell. By varying the sub-wavelength position of antennas, the phase of reflected light is modulated according to the gradient of geometric phase, enabling precise control of light direction without the response time limitations of conventional materials.
2Ease of operation
If beam steering is performed using conventional methods, then light direction can be changed, but side lobes are generated reducing signal-to-noise ratio
Solution Approach 1:
The patent applies local quality control by independently adjusting the phase of each unit cell in the meta-grating. Each nano-antenna position within a unit cell is optimized to contribute constructively to the main beam direction while minimizing side lobe formation. This localized phase control enables precise beam steering with suppressed side lobes, improving signal-to-noise ratio compared to conventional uniform beam steering methods.
3Speed
If meta-grating structure is used for high-speed operation, then response time is improved, but complex nano-antenna arrangement is required
Solution Approach 1:
The patent segments the meta-grating into repeating unit cells, each containing nano-antennas arranged in a standardized pattern. This segmentation allows the complex phase modulation function to be achieved through simple repetition of basic units, where each unit cell contributes to the overall geometric phase gradient. The segmented structure simplifies manufacturing while enabling high-speed operation through the absence of mechanical moving parts.
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 solution enables high-speed operation with reduced dispersion and improved SNR by maintaining constant amplitude while steering light, effectively reducing side lobes and enhancing beam steering precision.
Implementation Method 1
a first optical modulating element which changes a traveling direction of incidence light incident at a fixed incidence angle from an incidence optical system by using an effective displacement of a meta-grating
Implementation Method 2
there has been an attempt to utilize a meta structure using a surface plasmon resonance phenomenon with respect to incidence light in an optical modulating device
Implementation Method 3
an emission optical system configured to emit first-order diffraction light of the incidence light based on the meta-grating
Data Source
AI summary
Provided is an optical modulating device including an incidence optical system, an optical modulating assembly including a plurality of nano-antennas that form a meta-grating based on a driving signal, the optical modulating assembly being configured to change a traveling direction of incidence light incident at an incidence angle from the incidence optical system based on an effective displacement of the meta-grating according to the driving signal, and an emission optical system configured to emit light steered by the optical modulating assembly, wherein the emission optical system is further configured to emit first-order diffraction light of the incidence light based on the meta-grating.