Multipole Phase Beam Sorting via Circular-Sector Transformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing spatial division multiplexing/demultiplexing technologies face challenges in achieving high-resolution and flexible demultiplexing/multiplexing of electromagnetic beams with multipole phase patterns, particularly in optical communications, where there is a need for efficient separation and minimization of cross-talk between channels.
Innovation Solution
A device utilizing a conformal mapping of circular-sector transformation is employed to transform multipole phase beams into linear phases, allowing for separation and sorting of beams with different phase strengths and orientations using a sequence of beam transformer and phase corrector elements, followed by a focusing element to achieve demultiplexing/multiplexing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional spatial division multiplexing is used, then bandwidth capacity is improved, but cross-talk between channels increases and demultiplexing resolution deteriorates
Solution Approach 1:
The invention segments the multiplexed beam into multiple spatial channels using a conformal mapping transformation that separates different multipole phase components into distinct spatial regions. The beam transformer divides the input beam carrying multiple OAM modes into separate output beams, each corresponding to a specific multipole phase component, thereby achieving high-resolution demultiplexing while maintaining high bandwidth capacity
Solution Approach 2:
The conformal mapping transformation acts as an intermediary between the multiplexed input beam and the separated output channels. The beam transformer and phase corrector elements serve as intermediary optical components that facilitate the transformation from multipole phase domain to spatial domain, enabling clean separation of channels with minimal cross-talk
2Loss of information
If more multipole phase beams are multiplexed, then information capacity is improved, but cross-talk between channels increases
Solution Approach 1:
The invention transforms the problem from the angular dimension (azimuthal phase gradients) to the spatial dimension by using conformal mapping. Different multipole phase beams that overlap in the angular domain are separated in the spatial domain, allowing high information capacity through multiplexing while minimizing cross-talk through spatial separation of channels
3Productivity
If log-pol conformal transformation is used, then demultiplexing efficiency is improved, but device complexity increases
Solution Approach 1:
The invention merges the beam transformer and phase corrector into a single integrated optical element or closely coupled configuration. The conformal mapping transformation combines multiple functions (phase modulation, beam shaping, and spatial separation) into a unified optical system, achieving high demultiplexing efficiency while managing device complexity through functional integration
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-resolution and flexible demultiplexing/multiplexing of multipole phase beams, reducing cross-talk to less than -15 dB and allowing for efficient use of graded-index fibers in data centers, with applications in optical and other electromagnetic wavelength ranges.
Implementation Method 1
one of the most efficient and exploited is based on the log-pol conformal transformation mapping between orbital angular momentum and linear momentum states: the azimuthal phase gradients of OAM beams are unwrapped into tilted plane waves
Implementation Method 2
G. Ruffato, M. Girardi, M. Massari, P. Capaldo, G. Parisi, M. Zontin and F. Romanato, 'Demultiplexing of Orbital Angular Momentum Beams by diffractive optics'
Implementation Method 3
the azimuthal phase gradients of OAM beams are unwrapped into tilted plane waves, which can be easily separated or focused by using a Fourier lens
Implementation Method 4
which can be easily separated or focused by using a Fourier lens
Implementation Method 5
G. Ruffato, P. Capaldo, M. Massari, E.Mafakheri and F.Romanato, 'Total angular momentum sorting in the telecom infrared with silicon Pancharatnam-Berry transformation optics'
Data Source
Figure 1
Figure 2
AI summary
It is disclosed a device for multipole phase division multiplexing and demultiplexing and a spatial division telecommunications system comprising the multiplexing and demultiplexing devices. The multipole phase demultiplexing device (10) comprises a cascade of a beam transformer (2) and a phase corrector (3), wherein the beam transformer (2) performs a circular-sector transformation of a plurality of multipole phase electromagnetic beams (F1_l, F2_l). The multipole phase multiplexing device (50) comprises a cascade of a beam transformer (52) and a phase corrector (53), wherein the beam transformer (52) performs a combination of \ m\ circular-sector transformations of a plurality of tilted electromagnetic beams (F1.1*, F2.1*).