Beam Scanning Device Using Tilted Diffractive Units
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Solution Overview
Problem
Conventional beam scanning devices for optical wireless communication suffer from secondary diffracted light, leading to multimodal laser beam intensity with multiple peaks, which deteriorates communication quality, as they cannot produce a unimodal laser beam without mechanical components.
Innovation Solution
A beam scanning device incorporating a variable-wavelength laser, a plane-wave converting unit, and light-intensity-distribution converting units tilted in specific orientations to convert the laser beam into a unimodal plane-wave and then spherical-wave, suppressing secondary diffracted light and enabling two-dimensional scanning without mechanical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a conventional beam scanning device with a partially-transmissive etalon is used, then the laser beam can be scanned without mechanical movable components, but secondary diffracted light occurs causing multimodal light intensity with multiple peaks which deteriorates communication quality
Solution Approach 1:
The light-intensity-distribution converting unit is divided into a first light-intensity-distribution converting unit tilted in a horizontal direction and a second light-intensity-distribution converting unit tilted in a vertical direction. This segmentation allows independent control of diffraction patterns in different directions, enabling the suppression of secondary diffracted light while maintaining scanning capability without mechanical components.
Solution Approach 2:
The invention changes the tilt angles of the first and second light-intensity-distribution converting units to specific values (e.g., 45 degrees) to control the diffraction pattern. By adjusting these angular parameters, the device converts multimodal light intensity into unimodal light intensity, eliminating secondary diffracted light while maintaining contactless scanning.
2Object-generated harmful factors
If the light-intensity-distribution converting unit uses multiple tilted units, then secondary diffracted light is suppressed and unimodal light intensity is achieved, but the device complexity increases
Solution Approach 1:
The first and second light-intensity-distribution converting units are integrated into a single light-intensity-distribution converting unit with specific tilt configurations. This merging approach achieves unimodal light intensity suppression while reducing the number of separate components compared to using entirely separate optical systems for horizontal and vertical scanning.
Solution Approach 2:
The invention introduces tilt angles in both horizontal and vertical dimensions simultaneously within a single optical path. By utilizing three-dimensional spatial orientation of the converting units, the system achieves complex light intensity distribution control without requiring multiple sequential optical components, thereby managing device complexity.
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 device effectively suppresses secondary diffracted light, allowing for two-dimensional scanning of a unimodal laser beam, thereby enhancing communication quality by maintaining a single peak in light intensity, thus improving signal-to-noise ratio in optical wireless communication systems.
Implementation Method 1
secondary diffracted light occurs and light intensity of the laser beam is multimodal light intensity having a plurality of peaks
Data Source
AI summary
A beam scanning device includes a variable-wavelength laser that emits a laser beam, a plane-wave converting unit that converts the laser beam into a plane-wave laser beam, a light-intensity-distribution converting unit including a first light-intensity-distribution converting unit set to be obliquely tilted with respect to an emitting direction of the laser beam within a horizontal plane and a second light-intensity-distribution converting unit set to be obliquely tilted with respect to the emitting direction of the laser beam within a plane perpendicular to the horizontal plane and parallel to the emitting direction of the laser beam, the light-intensity-distribution converting unit converting a peak position of light intensity of the plane-wave laser beam according to a wavelength of the plane-wave laser beam, and a spherical-wave converting unit that converts the plane-wave laser beam, the peak position of the light intensity of which is converted, into a spherical-wave laser beam.