Waveguide Phase Shifting Elements for Coherent Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical systems face challenges in reducing coherent noise, which causes graininess and interference in images, particularly in devices like medical ultrasound and projection systems, due to spatial interference patterns and the limitations of free space diffusers in terms of size and integration.
Innovation Solution
An optical system incorporating a strip waveguide, a slab waveguide, a reflective element, and phase shifting elements, such as metal pads, which are heated to change the refractive index and phase of light, providing randomized phase shifts to mitigate coherent noise without the need for a free space diffuser.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a free space diffuser is used to reduce coherent noise, then coherent noise reduction is improved, but device size and integration complexity increase
Solution Approach 1:
The patent embeds the diffuser functionality within the waveguide structure itself. The waveguide includes a diffuser element integrated into its body, allowing light to undergo multiple reflections and phase shifts within the confined waveguide volume. This nesting approach eliminates the need for a separate free space diffuser while maintaining coherent noise reduction capabilities.
Solution Approach 2:
The patent transitions from free space diffraction to waveguide-based diffraction by confining light propagation to a structured medium. The waveguide geometry creates multiple reflection paths and phase shifts in a confined spatial dimension, achieving diffuser functionality without requiring the extended free space volume traditionally needed for coherent noise reduction.
2Object-affected harmful factors
If a free space diffuser is used to reduce coherent noise, then coherent noise reduction is improved, but integration into photonics devices becomes more difficult
Solution Approach 1:
The patent merges the waveguide function with the diffuser function into a single integrated component. The waveguide structure incorporates internal diffuser elements that create multiple reflection paths and phase shifts, eliminating the need for separate free space diffusers and reducing overall system integration complexity while maintaining coherent noise reduction.
3Object-affected harmful factors
If phase shifting elements are used to randomize light phase, then coherent noise reduction is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs phase shifting elements with locally varied properties within the waveguide. Different regions of the waveguide contain phase shifting elements with different refractive indices or thicknesses, creating localized phase shifts that collectively randomize the overall light phase. This local quality approach reduces the stringency of uniform manufacturing precision requirements across the entire device.
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 system effectively reduces coherent noise by generating light with randomized phase shifts, improving image quality and signal detection while maintaining system specifications like operating speed and size, and can be integrated into smaller photonics devices.
Implementation Method 1
the phase shifting elements may be a metal pad, which may be heated by applying a current to the metal pad
Implementation Method 2
As the phase shifting elements increase in heat, a local portion of the slab waveguide may also increase in temperature
Implementation Method 3
the index of refraction may shift. The shift in the index of refraction of the propagation region of the slab waveguide may cause the phase of the light to shift
Implementation Method 4
As the phase shifting elements increase in heat, a local portion of the slab waveguide may also increase in temperature and the index of refraction may shift
Implementation Method 5
a reflective element configured to reflect the light
Implementation Method 6
the reflective element may be parabolic-shaped and provide collimated light
Data Source
AI summary
Configurations for an optical system with phase shifting elements are disclosed. The optical system may include a first waveguide that provides light to a second waveguide, which may be a slab waveguide. A phase shifting element may be disposed on the slab waveguide and may be heated to induce a temperature change in the slab waveguide. By increasing the temperature of the propagation region of the slab waveguide, the index of refraction of the propagation region of the slab waveguide may shift, thus causing the index of refraction of light propagating through the propagation region to shift, thus shifting the phase of the light. This may result in an optical component capable of phase shifting light for reducing coherent noise while being energy efficient and maintaining a small form factor.