Sub-Wavelength Electrode Optical Modulation for Precise Phase Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies face challenges in providing accurate modulation of optical signals in a simple and compact manner, particularly in photonic integrated circuits, for applications such as laser operation, amplification, beam steering, and holographic image formation.
Innovation Solution
A device comprising an active layer with a plurality of electrodes, each smaller than the optical signal wavelength, separated by distances also smaller than the wavelength, allows for local modulation of the refractive index and gain, enabling precise control of optical signals through electrical signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single large electrode is used to modulate the optical signal, then the device structure is simple, but the modulation accuracy and spatial control are insufficient
Solution Approach 1:
The single large electrode is divided into multiple smaller electrodes arranged in an array. Each electrode has a cross-section smaller than the optical wavelength and can be independently controlled. This segmentation enables spatially selective modulation of the optical signal, achieving accurate control of amplitude, phase, and wavelength while maintaining a manageable device structure through systematic arrangement of the electrode elements.
2Ease of manufacture
If the electrode size is increased to cover the entire active layer, then the manufacturing is simpler, but the local modulation capability is lost
Solution Approach 1:
The electrode layer is segmented into multiple small electrodes that can be fabricated using standard photolithography and deposition techniques. The segmented structure is then integrated with the active layer, allowing each electrode to independently modulate the optical signal in its local region. This approach maintains manufacturing feasibility while enabling precise local control of optical properties.
Solution Approach 2:
Each electrode in the array is designed to interact with a specific local region of the optical signal. By applying electrical signals to individual electrodes, the device can locally modulate the refractive index and gain in different parts of the active layer, providing spatially varying control over the optical signal's amplitude, phase, and wavelength.
3Manufacturing precision
If the distance between electrodes is increased, then the manufacturing precision requirement is reduced, but the modulation accuracy of the optical signal deteriorates
Solution Approach 1:
The electrode spacing is optimized to be smaller than the optical wavelength, creating a sub-wavelength grating structure. This parameter choice enables the electrode array to function as an effective medium that can continuously modulate the optical signal without requiring extremely tight manufacturing tolerances. The sub-wavelength spacing allows the discrete electrodes to collectively provide smooth spatial modulation of the optical field.
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 device achieves accurate modulation of optical signals, allowing control of amplitude, phase, and wavelength, with applications in beam steering, three-dimensional light field generation, and optical data processing, while maintaining a compact form factor.
Implementation Method 1
The electrode layer provides an electro-optical effect by the electrical signal to the electrodes providing optical modulation
Data Source
AI summary
A device for modulation of an optical signal includes an active layer configured to provide electrically controlled gain of the optical signal; an electrode layer arranged to extend along the active layer, wherein the electrode layer comprises a plurality of separate electrodes associated with respective parts of the active layer, wherein each electrode have a size of a cross-section in the electrode layer smaller than a wavelength of the optical signal and neighboring electrodes are separated by a distance smaller than the wavelength of the optical signal; wherein an electrical signal to each of the electrodes is controllable for locally modulating an imaginary part of a refractive index of the active layer by locally controlling an electrical signal in the active layer.