Compact Optical Fiber Amplifier Using Flexible Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fiber-based optical amplifiers face challenges in reducing size and cost while maintaining performance, as the minimum bend radius of optical fibers limits further miniaturization and integration due to increased signal loss and physical failure risks.
Innovation Solution
A compact configuration featuring a fiber module with a flexible insulative substrate and pressure-sensitive adhesive, wound in a coil configuration with a support structure to maintain a defined minimum bend radius, allowing for mechanical strength and efficient amplification within a small footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the optical fiber is wound in a tighter coil configuration to reduce module size, then the volume of the optical amplifier is reduced, but the signal loss increases and physical failure risk increases due to exceeding minimum bend radius
Solution Approach 1:
The patent uses a flexible printed circuit board (FPC) as the substrate to wind the optical fiber in a coil configuration. The FPC's flexibility allows the fiber to be wound in tight coils while maintaining the minimum bend radius requirement, thus reducing module volume without increasing signal loss or physical failure risk. The FPC acts as a flexible carrier that conforms to the coil geometry while protecting the fiber.
Solution Approach 2:
The FPC serves as an intermediary between the rigid optical fiber and the compact coil configuration. It provides a flexible mounting surface that allows the fiber to be wound in tight coils while maintaining proper bend radius. The FPC mediates the mechanical stress and protects the fiber from direct contact with sharp edges or excessive bending forces.
2Device complexity
If various optical components are highly integrated and hybridized to reduce size, then the device complexity decreases, but the manufacturing precision requirements increase due to smaller component tolerances and assembly difficulties
Solution Approach 1:
The patent divides the optical amplifier into distinct functional modules: an optics module containing optical components (isolator, WDM filter, GFF filter) and a fiber module containing the amplifying fiber wound on the FPC. This segmentation allows each module to be manufactured and tested independently with standard precision requirements, then assembled together. The FPC-based fiber module is a self-contained unit that simplifies the integration process.
Solution Approach 2:
The FPC serves multiple functions simultaneously: it provides mechanical support for the optical fiber, enables compact coil winding while maintaining bend radius, provides electrical insulation, and facilitates integration with the optics module. This multi-functionality reduces the number of separate components needed, simplifying the overall device structure without compromising manufacturing precision.
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 configuration enables smaller, cost-effective optical amplifiers with reduced signal loss and increased mechanical stability, enabling further integration and miniaturization while maintaining performance.
Implementation Method 1
The fiber itself is wound in a coil configuration on the insulative material and held in place by the adhesive coating
Implementation Method 2
The presence of the pump light with the erbium dopant generates amplification of the propagating optical signal by the transitions of the optically-excited erbium ions
Implementation Method 3
The presence of these pulses (either co-propagating or counter-propagating with respect to the optical signal) excites the photons to higher energy levels, where the photons create stimulated emission as they return to their ground state
Data Source
AI summary
A fiber-based optical amplifier is assembled in a compact configuration by utilizing a flexible substrate to support the amplifying fiber as flat coils that are “spun” onto the substrate. The supporting structure for the amplifying fiber is configured to define the minimal acceptable bend radius for the fiber, as well as the maximum diameter that fits within the overall dimensions of the amplifier package. A pressure-sensitive adhesive coating is applied to the flexible substrate to hold the fiber in place. By using a flexible material with an acceptable insulative quality (such as a polyimide), further compactness in the final assembly is achieved by locating the electronics in a space underneath the fiber enclosure.