Fiber Bragg Grating Holder for Stable OH Wavelength Suppression
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Solution Overview
Problem
Existing optical filter systems for suppressing predetermined wavelengths, such as the hydroxyl (OH) line in light waves, are time-consuming and prone to measurement inaccuracies due to the need for precise adjustment of holding voltage and susceptibility to thermal effects, which complicates the process and increases the risk of damage to the optical fiber.
Innovation Solution
An optical filter system with a fiber holder that allows the optical fiber to remain fixed during fiber Bragg grating inscription and filtering, featuring adjustable holding tension and a coverable cutout window to protect the fiber, along with a holding voltage that compensates for thermal changes, ensuring reliable and reproducible wavelength suppression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the optical fiber is removed from the fiber holder for insertion into a measuring apparatus, then wavelength filtering measurement can be performed, but the process becomes very time-consuming and increases user effort
Solution Approach 1:
The patent merges the fiber holder with the measuring apparatus by integrating the fiber holder directly into the apparatus structure. This allows the optical fiber to remain permanently mounted in the fiber holder during both inscription and measurement processes, eliminating the need for repeated removal and insertion operations while maintaining measurement accuracy through consistent fiber positioning and holding tension.
Solution Approach 2:
The patent applies preliminary action by pre-mounting the optical fiber in the fiber holder before the measurement process begins. The fiber is tensioned and positioned in advance, and the fiber holder is integrated into the measuring apparatus beforehand, so that no time-consuming adjustment or reinstallation is needed during actual measurements.
2Measurement precision
If precise adjustment of holding voltage is performed during measurement, then accurate wavelength filtering is achieved, but the process complexity and user effort increase
Solution Approach 1:
The patent applies self-service by designing the fiber holder with automatic tension maintenance features that eliminate the need for manual holding voltage adjustment during measurements. The integrated structure provides consistent mechanical support and tensioning, allowing the system to self-regulate without requiring user intervention for precise voltage adjustments, thereby simplifying the operation while maintaining filtering accuracy.
3Reliability
If the optical fiber is repeatedly removed and inserted, then measurement can be performed, but the risk of damage to the optical fiber increases
Solution Approach 1:
By merging the fiber holder with the measuring apparatus, the patent creates a permanent mounting solution where the optical fiber remains continuously secured. This integration eliminates repeated handling operations that could damage the fiber, thereby protecting fiber integrity while maintaining reliable measurement capability throughout the system's operational life.
4Ease of operation
If holding tension is not constant during recording and filtering, then the system is easier to operate, but measurement inaccuracies occur
Solution Approach 1:
The integrated fiber holder design provides self-service by automatically maintaining constant holding tension through its structural design. The fiber is permanently mounted with predetermined tensioning features that self-regulate during operation, eliminating the need for user adjustments while ensuring consistent tension for accurate wavelength filtering measurements.
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 system reduces user effort, minimizes measurement inaccuracies, and provides athermic performance by maintaining consistent holding tension, thus enhancing the reliability and durability of wavelength filtering, particularly in near-infrared spectroscopy applications.
Implementation Method 1
Depending on the effective refractive index of the optical fiber and other details of the lattice structure, such as the periodicity of the lattice layers, a wavelength range is reflected back in the light waves transported through the optical fiber and thereby suppressed in transmitted light waves
Implementation Method 2
a holding voltage that compensates for thermal changes, ensuring reliable and reproducible wavelength suppression
Data Source
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AI summary
The invention relates to an optical filter system (100) for wavelength filtering, in particular for suppressing the hydroxyl (OH) line in received light waves (105), comprising an optical fiber (110) and a fiber holder (120). The optical fiber has a fiber core (114) extending in the direction (112) of the optical fiber with a refractive index nK, in which a fiber Bragg grating (115) consisting of grating layers (117) repeating in the direction of extension with a refractive index nG is inscribed.The fiber holder is arranged and configured to pretension the optical fiber with an adjustable holding tension, wherein the fiber holder has at least one cutout window (125) which can be opened for a marking process for inscribing the fiber Bragg grating and closed for wavelength filtering by a cover device (127) of the fiber holder, and wherein the optical fiber is fixed in the fiber holder such that at both ends (118, 118') of the optical fiber a respective free fiber end (119, 119') is provided outside the fiber holder in such a way that the respective free fiber end can be connected to a respective other external optical fiber (130, 130').