Multimode Waveguide Beam Homogenization via Optical Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multimode optical waveguides produce highly structured, inhomogeneous beam profiles due to multiple propagation modes and interference, which is problematic for applications requiring uniform illumination or machining, as existing solutions like mechanical vibrations or movable diffusers are complex and not always effective.
Innovation Solution
The method involves splitting coherent light into multiple beam paths, modulating the radiation in these paths, and combining them to create temporally varying interference patterns at the input of the multimode waveguide, which results in a homogeneous beam profile upon temporal integration, utilizing a photonic integrated circuit for compact and high-frequency modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If mechanical vibrations are applied to the MMF to achieve homogenization, then the beam profile homogeneity is improved, but the device complexity and mechanical reliability deteriorate
Solution Approach 1:
The patent replaces the mechanical vibration system with an optical modulation system. Instead of physically vibrating the MMF, the invention uses modulators to vary optical parameters (phase, amplitude, or polarization) of light coupled into different modes of the MMF, achieving homogenization without mechanical moving parts.
Solution Approach 2:
The patent introduces optical modulators as intermediary devices between the light source and the MMF. These modulators act as mediators that control the excitation of different propagation modes through optical field manipulation rather than mechanical disturbance, simplifying the overall system architecture.
2Stability of the object's composition
If a movable diffusor is used to homogenize the beam profile, then the illumination uniformity is improved, but the device complexity and potential misalignment issues worsen
Solution Approach 1:
The patent replaces the mechanically movable diffusor with a stationary optical modulation system. The homogenization is achieved by controlling the optical fields coupled into different modes of the MMF through modulators, eliminating the need for mechanical movement and associated alignment complexities.
Solution Approach 2:
The patent introduces temporal dynamics through optical modulation rather than mechanical movement. The modulators dynamically adjust optical parameters in real-time to create temporally varying interference patterns, achieving homogenization through temporal averaging without any mechanical moving parts.
3Stability of the object's composition
If single-mode optical waveguides are used to maintain Gaussian beam profile, then the beam profile stability is improved, but the applicability for homogeneous illumination deteriorates
Solution Approach 1:
The patent segments the optical field into multiple propagation modes of the MMF, each carrying a portion of the total optical power. By independently controlling the excitation of these modes through modulation, the system can synthesize a homogeneous intensity distribution at the output, combining the stability of modal propagation with the versatility of customizable beam profiles.
Solution Approach 2:
The patent changes the excitation parameters of different propagation modes through optical modulation. By dynamically adjusting the phase, amplitude, or polarization of light coupled into specific modes, the system transforms the inherent Gaussian profile of single-mode coupling into a homogeneous output profile suitable for illumination applications.
4Shape
If MMF with special core geometry is used to achieve top hat profile, then the beam profile shape control is improved, but the manufacturing precision and alignment requirements worsen
Solution Approach 1:
The patent changes the optical excitation parameters of the MMF modes rather than relying on precise geometric control of the fiber core. Through optical modulation, the system dynamically controls which modes are excited and with what amplitude, enabling flexible beam profile shaping without stringent manufacturing tolerances on the waveguide geometry.
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
This approach achieves a homogeneous beam profile by varying the excitation of modes over time, optimizing homogeneity through temporal modulation, even at high frequencies, suitable for applications like wide field microscopy and material machining.
Implementation Method 1
modulating the radiation in at least one of the beam paths
Implementation Method 2
in the case of propagation of coherent radiation through transversal multimode waveguides a highly structured, i.e. inhomogeneous, beam profile results at the output, on account of the plurality of possible propagation modes and the interference thereof
Data Source
AI summary
The invention relates to a method for homogenization of the output beam profile of a multimode optical waveguide (10). The method comprises the following method steps:splitting input radiation (2) of coherent light over two or more beam paths (I-IV),modulating the radiation in at least one of the beam paths (I-IV),combining the beam paths (I-IV) by superimposing the modulated radiation onto the input (9) of the multimode waveguide (10), where the radiation forms a temporally variable interference pattern, andpropagating the radiation using the multimode waveguide (10).The invention furthermore relates to a device for carrying out the method. At least one splitting device (14) which is designed to split input radiation (2) over two or more beam paths (I-IV), at least one modulator (16) which is designed for modulating the radiation in at least one of the beam paths (I-IV), and at least one superimposition device which is designed for combining the beam paths (I-IV) by superimposing the modulated radiation and for directing the superimposed radiation onto the input (9) of the multimode optical waveguide (10), are components of a photonic integrated circuit (3) according to an embodiment of the device.