Optoelectronic Sensor Alignment via Nonlinear Frequency Multiplication
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Solution Overview
Problem
The alignment of optoelectronic sensors using infrared light is challenging due to the invisibility of infrared signals, leading to complex and prone-to-misalignment systems with additional pilot beams, increasing component complexity.
Innovation Solution
Converting part of the infrared measuring light beam into a visible pilot light beam through frequency multiplication using a nonlinear optical element, such as a metasurface, eliminating the need for a separate pilot light source and allowing for easier alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a separate pilot light source is used to provide a visible pilot beam, then the alignment of the sensor becomes easier, but the device complexity and number of components increase
Solution Approach 1:
The patent combines the pilot beam generation function with the existing infrared measuring light source by using a nonlinear optical element (such as a Pockels cell or frequency doubling crystal) that converts a portion of the infrared measuring light into a visible pilot beam through frequency multiplication. This eliminates the need for a separate pilot light source while maintaining the alignment assistance function.
Solution Approach 2:
The infrared measuring light source serves dual purposes: it functions as both the primary measuring beam source and the generator of the visible pilot beam through the nonlinear optical element. This multi-functionality reduces the total number of components while maintaining both measurement and alignment capabilities.
2Ease of operation
If a dichroic mirror is used to superimpose the pilot beam onto the measuring beam, then alignment becomes possible, but the system size and alignment complexity increase
Solution Approach 1:
The patent extracts the wavelength conversion function into a separate nonlinear optical element placed in the beam path of the infrared measuring light. This approach eliminates the need for beam splitting and recombination optics like dichroic mirrors, thereby reducing system size and optical alignment complexity while still producing a visible pilot beam for alignment purposes.
3Device complexity
If frequency multiplication is used to convert infrared measuring light into a visible pilot beam, then the pilot beam is generated without additional light sources, but nonlinear optical elements require specific conditions
Solution Approach 1:
The patent introduces a nonlinear optical element (such as a Pockels cell or frequency doubling crystal) as an intermediary component that facilitates the conversion of infrared measuring light into a visible pilot beam. This intermediary enables wavelength transformation without requiring separate light sources, while the element's specific optical properties help manage the precision requirements through controlled interaction with the light beam.
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 simplifies the alignment process, reduces sensor complexity, and enables more efficient frequency conversion with lower measuring light powers, resulting in a compact and cost-effective design.
Implementation Method 1
converting at least part of a measuring light beam emitted by a measuring light source of an optoelectronic sensor in the infrared wavelength range into a pilot light beam in the visible wavelength range by means of frequency multiplication. This can be achieved using known methods of frequency doubling ('second harmonic generation', SHG) or frequency tripling ('third harmonic generation', THG), whereby the frequency of the irradiated measuring light beam is doubled or tripled in a nonlinear optical element.
Data Source
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AI summary
An optoelectronic sensor is described, comprising at least one measuring light source for emitting at least one measuring light beam in the infrared wavelength range along a transmitting beam path into a monitoring area, a light receiver for receiving measuring light beams emitted or reflected from the monitoring area and generating corresponding received signals, and a control and evaluation unit for controlling the light receiver and the measuring light source and for evaluating the received signals. The optoelectronic sensor includes at least one nonlinear optical element for generating at least one pilot light beam in the visible wavelength range from at least a portion of the measuring light beam.