Spatial Optical Transceiver Beam Spread Control for Stable Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing spatial optical communication transceivers face challenges in maintaining stable communication paths over varying distances due to dynamic range issues in light receivers and noise fluctuations from electrical gain control, leading to increased internal optical system loss and S/N fluctuations.
Innovation Solution
A spatial optical communication transceiver that adjusts the focal length of a collimator lens using a drive mechanism to maintain a constant product of free space loss and transmission gain, independent of electrical gain variation, by controlling the beam spread angle of transmission light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a variable attenuator is used on the receiver side to correct light intensity variations, then the dynamic range of the light receiver is extended, but the number of components increases and device complexity increases
Solution Approach 1:
The invention extracts the light intensity adjustment function from the receiver side and relocates it to the transmitter side through the optical amplifier gain control. This removes the need for variable attenuators and other adjustment components on the receiver side, thereby reducing device complexity while maintaining the ability to handle wide dynamic range requirements
Solution Approach 2:
The invention introduces an optical amplifier as an intermediary component on the transmitter side that actively compensates for free space loss variations. This mediator adjusts its gain dynamically based on distance changes, eliminating the need for passive attenuators on the receiver side and simplifying the overall system architecture
2Measurement precision
If a variable attenuator is used on the receiver side to adjust light amount, then the light receiving sensitivity is corrected, but the internal optical system loss increases in long-distance communication
Solution Approach 1:
Instead of attenuating light on the receiver side (which increases optical loss), the invention inverts the approach by amplifying light on the transmitter side before transmission. This proactive amplification compensates for free space loss without introducing additional internal optical losses that would occur with receiver-side attenuation
3Adaptability or versatility
If electrical control of OHPA gain is used to cope with distance variation, then the output light intensity is adjusted, but amplified spontaneous emission is induced and noise figure deteriorates
Solution Approach 1:
The invention implements dynamic gain control of the optical amplifier based on real-time distance information between transmitter and receiver. By continuously adapting the amplifier gain to match the free space loss at different distances, the system maintains optimal signal levels without excessive gain that would induce amplified spontaneous emission and noise figure deterioration
4Length of stationary object
If the beam spread angle is reduced to increase transmission gain, then the communication distance is extended, but the coverage area decreases
Solution Approach 1:
The invention changes the parameter being controlled from beam spread angle to optical amplifier gain. By adjusting the gain parameter instead of the geometric beam parameter, the system can extend communication distance through amplification without sacrificing coverage area, as the beam spread angle remains unchanged and wide coverage is maintained
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
Enables stable communication over varying distances without electrical gain variation, reducing noise fluctuations and maintaining signal integrity.
Implementation Method 1
a collimator including a fiber connector and a collimator lens to convert the laser beam amplified by the optical amplifier into spatial light, and emit transmission light that is the spatial light
Implementation Method 2
an optical telescope to enlarge a beam width of the transmission light emitted by the collimator and emit the transmission light to a spatial transmission path
Data Source
AI summary
There are provided: a light source to generate a laser beam; an optical modulator to superimpose a communication signal on the laser beam; an OHPA to amplify the laser beam; a collimator including a fiber connector and a collimator lens to convert the laser beam amplified into spatial light, and emit the spatial light; an optical telescope to enlarge a beam width of the spatial light and emit the spatial light to a spatial transmission path; a drive mechanism capable of adjusting a focal length of the collimator lens; and a drive controller to determine a drive amount of the drive mechanism in such a manner that a product of a free space loss calculated from a distance between the spatial optical communication transceiver and a spatial optical communication transceiver and a transmission gain determined by a beam spread angle of the spatial light is constant.