ASYM: Coated fiber asymmetry measurement
A new approach to fiber coating asymmetry control
Traditional visual systems for eccentricity measurement become ineffective when coating thickness decreases below 200 µm.
The ASYM uses a dual-axis laser interferometric method that analyses the interference pattern created by the light passing through the cladding and coating layers.
From these fringes, the system calculates an “asymmetry” value representing the global deviation induced by the eccentricity of each layer (glass, primary, and secondary coatings).
This advanced principle allows manufacturers to:
- Quantify coating asymmetry with exceptional precision
- Monitor the process in real time, even when the fiber is spinning
- Optimize coating application by adjusting parameters instantly
Reliable, real-time measurements for next-generation fibers
With coating diameters now ranging between 165 and 250 µm, ensuring concentricity is more critical than ever.
The ASYM provides continuous, high-resolution monitoring that helps fiber manufacturers:
- Control eccentricity on ultra-thin coatings
- Reduce waste and non-conformities through process optimization
- Guarantee consistent quality and compliance with industry standards
The ASYM can be positioned at different points along the draw tower before or after UV curing depending on the coating process and refractive index contrast, ensuring optimal accuracy in all configurations.
Our software solution
for fiber optic measurement
CIM Software - Instrument manager
Our advanced CIM PROD PC software is a complete, production quality management tool for operators.
It comes with our instruments to provide their parameter settings, to clearly display the production measurements as well as any detected defects, and to generate real-time parameters and record all the measurements and events in a data base.
The PROD Full version has been developed for IN-LINE fiber optics measurements. Adjustment of tolerances, triggering threshold, and spool replacement are specific features for the production environment.
Our other fiber optic measurement tools
LISG: Laser Interferometric Sensor for Glass
5 in 1 gauge ! Ultra fast detection.
The LISG is designed for bare optical fiber measurements and for checking for defects during drawing. It uses interferometric fringe patterns produced by a fiber when placed in a laser beam.
Primary features :
- Real-time, high accuracy diameter measurements
- Airline defect detection (bubbles in the preform)
- Cladding non-circularity measurements
- Spinning profile and frequency measurements
AIR: Ultra fine "airline"
100% glass cross-section coverage
The AIR is designed to detect airline defects (bubbles in the preform stretched during drawing) in optical fibers. It uses the interferometric fringe patterns produced by a fiber when placed in a laser beam.
The measurement principle provides ultra fine airline detection, down to 0.3µm. By using 3 measurement axes, the AIR is the only instrument able to detect 100% of the airlines (with or without spinning) by covering 100% of the cross-section. Measurements are fiber position and vibration independent.
NCTM: Non Contact Tension Measurement
Purely optical principle!
The NCTM is designed to measure the drawing force (tension) during optical fiber production. It uses a purely optical principle based on birefringence (light polarization).
Measurement capability from start to finish of the drawing process. Range: 0 - 400 grams, uncertainty: +/- 1 gr
CM5: Coating Monitor 5 axes
All-in-one! Diameter and lump & neck detection
The CM5 is designed for coated optical fiber measurements and for checking for defects during drawing.
With its 5 measuring axes that cover 100% of the surface, and its exceptional measuring speed, the CM5 is the perfect instrument for a complete inspection of the coated fiber :
- Measurement of the outer diameter of the coated optical fiber
- Continuous detection of lump and neckdown flaws
- Detection of internal and surface defects and impurities in the cladding
- Detection of flaws, bubbles, delamination within the coated layers
- Measurement of the asymmetry of the glass within coating layers.
Our accessory tool for fiber optic measurement
CS-FO
The CS-FO is an accessory specially designed for calibrating and testing our fiber optic measurement equipment.
At the request of our main customers, we have marketed this accessory, which can be used to check the correct behavior of each measuring instrument, and to adjust the nominal diameter or tension (drawing force) for a specific fiber.
Articles related to the measuring tools for optical fiber category and the ASYM product
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