Optical Phased Array OPD Correction for Diffraction-Limited Beams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical phased arrays (OPAs) face challenges in maintaining diffraction-limited beams due to environmental and fabrication non-idealities, particularly when used in long-distance applications like free space optical communications and LiDAR, as variations in wafer properties cause light to propagate at different rates through waveguides.
Innovation Solution
Implementing corrective optical path differences (OPD) in the near-field of OPAs to cancel out aberrations by generating a spatially-varying OPD across the aperture that is equal and opposite to the aberration, using methods such as static corrections applied directly to the OPA, static corrections with auxiliary elements, and tunable corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If optical phased arrays are used for long-distance transmission and reception of laser light, then the application utility is improved, but the ability to maintain diffraction limited beams deteriorates due to environmental and fabrication non-idealities
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-applying corrective optical path differences to compensate for anticipated aberrations. The system determines the aberration correction phase shifters' settings before actual beam transmission, based on measured or modeled aberration patterns from fabrication non-idealities and environmental conditions, thereby proactively maintaining diffraction-limited beam quality.
Solution Approach 2:
The patent changes physical parameters by adjusting the phase shift values of individual antenna elements in the optical phased array. By dynamically modifying the phase parameter of each element's emitted light and combining it with measured aberration patterns, the system compensates for wavefront distortions and restores diffraction-limited beam quality despite fabrication variations and environmental disturbances.
2Device complexity
If standard optical phased array structures are used, then device simplicity is maintained, but aberration correction capability is insufficient
Solution Approach 1:
The patent introduces an intermediary corrective element (such as a phase plate or spatial light modulator) positioned in the optical path between the optical phased array and the target. This intermediary component applies the calculated aberration correction phase shifts to the emitted beam, separating the correction function from the basic OPA structure and enabling reliable aberration compensation without fundamentally redesigning the entire system.
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 proposed methods and structures effectively correct aberrations in OPAs, ensuring diffraction-limited beam transmission and reception by compensating for fabrication and environmental variations, thereby enhancing performance in long-distance applications.
Implementation Method 1
employ a corrective optical path difference (OPD) in the near-field of an OPA to correct or cancel out aberrations in emitted beams of the OPA
Implementation Method 2
generate a spatially-varying OPD across the aperture of the OPA that is substantially equal and opposite to an equivalent OPD of the aberration(s)
Data Source
AI summary
Aspects of the present disclosure describe systems, methods, and structures for aberration correction of optical phased arrays that employ a corrective optical path difference (OPD) in the near-field of an OPA to correct or cancel out aberrations in emitted beams of the OPA including those reaching far-field distances by generating a spatially-varying OPD across the aperture of the OPA that is substantially equal and opposite to an equivalent OPD of the aberration(s).