Deformable Mirror Retro-Reflector Remote Sensing
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Solution Overview
Problem
Conventional free-space optical remote sensing techniques, such as Brillouin and Raman lidar, face limitations due to low molecular backscatter levels and the difficulty in using Raman techniques in restricted transmission environments like underwater settings, where the signal strength is insufficient for effective monitoring.
Innovation Solution
A system utilizing retro-reflective optical elements with a deformable mirror that adjusts to counteract wavefront distortions, enhancing the intensity of returned light by up to five times, allowing for improved signal-to-noise ratio and extended range in remote sensing applications, particularly in marine environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional free-space optical remote sensing techniques (Brillouin and Raman lidar) are used to monitor environments, then molecular backscatter information can be obtained, but the signal strength is too weak for effective monitoring, especially in restricted transmission environments like underwater
Solution Approach 1:
The patent introduces retro-reflective optical elements as intermediaries in the monitored environment. These elements are illuminated by a remote light source and return retro-reflected light to the detector, enabling indirect sensing without requiring the light source and detector to be in direct line of sight through the monitored medium. This mediator approach overcomes the weak signal problem in restricted transmission environments.
Solution Approach 2:
The system pre-positions retro-reflective optical elements within the monitored environment before measurement. These elements are strategically placed to ensure they will reflect light back to the detector when illuminated, enabling reliable remote sensing without requiring real-time adjustment or complex real-time optimization of the optical path.
2Loss of information
If Raman scattering techniques are used to obtain molecular information, then detailed spectral data can be acquired, but the technique becomes difficult to use in environments with restricted transmission windows such as underwater
Solution Approach 1:
Retro-reflective optical elements serve as intermediaries that carry spectral information markers. These elements can be designed with specific optical properties (such as fluorescent materials or interferometric structures) that encode environmental information in their retro-reflected light, enabling spectral analysis without requiring direct transmission of probe light through the monitored medium.
Solution Approach 2:
Instead of sending probe light through the monitored environment to detect molecular backscatter (conventional approach), the system inverts the approach by placing passive retro-reflective elements in the environment that return light to the detector. This inversion eliminates the need for light to traverse the restricted transmission medium twice, overcoming the limitations of Raman techniques in underwater environments.
3Length of stationary object
If the distance between the remote light source and detector is increased to enable remote sensing, then the ability to monitor distant environments is improved, but the returned optical signal becomes too weak to detect
Solution Approach 1:
Retro-reflective optical elements act as intermediaries that are positioned at the remote location to be sensed. These elements collect light from the remote source and return it directly back to the detector with high efficiency, maintaining signal strength over long distances without requiring the light to travel the full round-trip distance through attenuating media.
Solution Approach 2:
The retro-reflective optical elements serve multiple functions: they act as targets for illumination, as retro-reflectors to return light to the detector, and as carriers of environmental information. This multi-functionality enables a single component to address multiple challenges in remote sensing simultaneously, including signal strength maintenance and environmental parameter encoding.
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 significantly enhances the strength and stability of the optical signal returned from retro-reflective elements, improving the efficacy of remote sensing by maintaining a more spatially stable illumination, thereby enabling effective monitoring in previously challenging environments.
Implementation Method 1
the reflector unit is arranged to deform the deformable mirror according to the determined wavefront such that light from the light source is reflected by the deformable mirror so deformed to output illumination light with a modified wavefront
Implementation Method 2
Conventional free-space optical remote sensing techniques rely on irradiating a monitored environment with light intended to interact with that environment in a manner which produces a detectable change. In particular, by analysing the light that has been backscattered by target molecules
Implementation Method 3
The optical element(s) which bears a photo-luminescent material having a photo-luminescent response that is dependent upon a physical property of the monitored environment
Implementation Method 4
Both processes have a dependence on temperature, as well as other physical parameters. The energy exchanges associated with Raman scattering are usually much larger (×1000) than those associated with Brillouin scattering
Implementation Method 5
those involving energy exchanges with molecular vibrational states, known as Raman scattering
Data Source
AI summary
A system for remotely sensing light from within a monitored environment containing one or more retro-reflective optical elements. The system includes an illuminator including a light source and a reflector unit comprising a deformable mirror arranged to receive light from the light source and to reflect the received light. This outputs illumination light from the illuminator for illuminating the optical element(s) within the monitored environment. A detector is arranged to receive light returned by the one or more retro-reflective optical elements in response to the illumination light. The detector determines a wavefront of the returned light and detects a property of the monitored environment according to the returned light. The reflector unit is arranged to deform the deformable mirror according to the determined wavefront such that light from the light source is reflected by the deformable mirror so deformed to output illumination light with a modified wavefront.