Optical Phased Array Beam Steering via Photocarrier Index Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser technologies face challenges in achieving narrow line width, high stability of emission wavelength and power, and efficient beam control without mechanical complexity or increased construction volume, particularly in applications like RGB projections and LIDAR.
Innovation Solution
Utilizing optical phased arrays (OPAs) with optically controlled waveguide arrays to modulate the refractive index through absorption of high-energy photons, generating free charge carriers for fast and wear-free beam control and modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanical mirrors or MEMS are used for beam deflection, then beam control capability is improved, but device complexity and robustness deteriorate
Solution Approach 1:
The patent replaces mechanical beam deflection systems (mirrors, MEMS) with an optical phase array that uses optical paths and phase modulation to achieve beam control. This substitution eliminates moving parts while maintaining beam steering capability through constructive and destructive interference of light waves in different waveguides.
Solution Approach 2:
The patent introduces an optical intermediary (the optical phase array with multiple waveguides) that mediates beam control through phase manipulation rather than mechanical movement. The phase modulators act as intermediaries that convert electrical control signals into optical phase changes, which then steer the beam without mechanical components.
2Area of stationary object
If pixel array projections are used to cover field of view, then beam coverage is improved, but efficiency and contrast deteriorate
Solution Approach 1:
The patent applies local quality by concentrating optical energy into a focused beam that can be precisely directed to specific regions of the field of view, rather than uniformly illuminating the entire field with a pixel array. This localized energy concentration improves efficiency while maintaining the ability to cover the required field of view through beam steering.
3Power
If edge-emitting lasers are used for high output power, then power capability is improved, but wavelength stability and line width deteriorate
Solution Approach 1:
The patent segments the laser system into two functional parts: an edge-emitting laser that provides high output power, and an external optical phase array that provides wavelength stabilization and line width narrowing. This segmentation allows each component to optimize its respective function without compromise.
Solution Approach 2:
The external optical phase array acts as an intermediary that stabilizes the wavelength and narrows the line width of the edge-emitting laser output. The feedback mechanism in the external cavity serves as a mediator that continuously adjusts the optical path to maintain precise wavelength control while preserving the high power output of the edge-emitting laser.
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 high-frequency modulation with small form factors, reducing mechanical complexity and enhancing beam control efficiency, suitable for applications requiring stable wavelength and power, such as RGB projections and LIDAR.
Implementation Method 1
modulation light can be conducted to the first waveguide array... The first band gap is smaller than the photon energy of the modulation light... absorbing the irradiated modulation light, charge carriers are generated in the first waveguide array, which change the refractive index
Implementation Method 2
These free charge carriers are generated by absorbing photons with higher energy than the band gap... This results in a modulation of the refractive index, whereby the modulation speed is essentially limited by the lifetime of the charge carriers in the material
Data Source
AI summary
The invention relates to an optical phase array with a signal input for supplying use light of a first wavelength and a first modulation input for supplying modulation light of a second wavelength. A first waveguide array with at least one signal output is connected to the signal input and comprises a material transparent to the use light and having a first bandgap. A second waveguide array connected to the first modulation input is arranged and designed in the vicinity of the first waveguide array in such a way as to guide modulation light onto the first waveguide array, the first band gap being smaller than the energy of the modulation light.