Laser Radar Device Using Partial Reflector for Local Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser radar devices using coherent detection for wind speed measurement require costly polarization-maintaining components and additional optical components like splitters and multiplexers, increasing complexity and cost.
Innovation Solution
A laser radar device configuration that uses a pulse-modulated optical signal with an optical partial reflector to reflect a low-level component of the signal for coherent detection, eliminating the need for polarization-maintaining systems and reducing the necessity for optical splitters and multiplexers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polarization-maintaining components and optical splitters/multiplexers are used to maintain high detection efficiency, then coherent detection efficiency is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the local light signal from the transmitted pulse signal by utilizing the low-level portion of the pulse waveform itself, rather than requiring separate optical splitting components. The local light is obtained by reflecting the low-level section of the pulse-modulated optical signal using a simple optical reflector, eliminating the need for complex optical splitters and multiplexers while maintaining coherent detection efficiency
Solution Approach 2:
The transmitted pulse signal serves multiple functions: it acts as both the transmission light for illuminating the atmosphere and as the source of local light for coherent detection. By using the low-level section of the same pulse signal for both purposes, the system eliminates the need for separate local light generation paths and associated optical components, thereby simplifying the overall device configuration
2Reliability
If polarization-maintaining components are used to match polarization of scattered light and local light, then detection efficiency is improved, but cost increases
Solution Approach 1:
The patent changes the temporal parameter of the optical signal by utilizing different sections of the pulse waveform (high-level for transmission, low-level for local light). This temporal parameter change allows the system to obtain local light with matched polarization characteristics without requiring polarization-maintaining components, thereby reducing cost while maintaining detection efficiency
3Ease of operation
If optical splitters and multiplexers are used to separate and combine light signals, then signal separation and combination are improved, but device complexity and cost increase
Solution Approach 1:
The patent uses a simple optical reflector as an intermediary element to obtain the local light signal by reflecting the low-level section of the transmitted pulse. This simple reflective intermediary replaces complex optical splitters and multiplexers, achieving signal separation and combination functionality while significantly reducing device complexity and cost
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
Simplifies the configuration, reduces costs, and maintains high coherent detection efficiency without the need for polarization-maintaining optical components, while enabling simultaneous wind speed distribution measurement in the distance direction.
Implementation Method 1
an optical partial reflector to reflect the optical signal, the optical partial reflector being provided on a path through which the transmission light is transmitted from the circulator to the atmosphere
Implementation Method 2
a detector to perform coherent detection on the reception light using, as local light, a signal in a Low level section of the optical signal reflected by the optical partial reflector
Implementation Method 3
a circulator to transmit the optical signal as transmission light and acquire reflection light from a target in an atmosphere as reception light
Implementation Method 4
systems using coherent detection that enables Doppler frequency measurement
Data Source
AI summary
An optical transmission unit (3) transmits an optical signal having a light intensity set as a Low level component of a pulse. An optical partial reflector (6) is provided on a path through which transmission light is transmitted from a circulator (5) to the atmosphere, and reflects the optical signal. A detection unit (11) performs coherent detection on reception light using, as local light, a signal in a Low level section in the optical signal reflected by the optical partial reflector (6).