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Wavelength Range of Fiber Bragg Grating Sensors - Fiber Bragg Gratings with Encapsulated C-Band and Customizable Wavelengths
This article introduces the concept of wavelength customization for FBG sensors and under what circumstances the wavelength of the sensors can be customized. It answers the question of "Can the wavelength of FBG sensors be customized?" and provides the wavelength customization range for OFSCN® Capillary Seamless Steel Tube FBG Sensors.
It should be noted that whether it is a FBG temperature sensor (FBG thermometer), FBGstrain sensor (FBG strain gauge), or FBG stress sensor (FBG stress gauge), wavelength customization can be done. However, it comes with a higher price and longer production cycle.
1. Can the Wavelength of FBG be Specified?
Each OFSCN® Capillary Seamless Steel Tube FBG Sensor has a unique FBG wavelength during production. The wavelength can theoretically be any value between 1525nm and 1565nm, as well as values near the 850nm or 1310nm bands, or other values within the range of 400nm to 2200nm (typical example being 1064nm). However, there are certain limitations to defining the wavelength.
FBG written using ultraviolet photomask methods have their wavelengths limited by the photomask. Once the parameters of the photomask are determined, the FBG produced using that photomask will have a predetermined wavelength.
On the other hand, FBG written using femtosecond laser point-by-point inscription can have their wavelengths freely adjusted.
The wavelength value can be used to produce all types of FBG sensors (FBG temperature, stress, strain sensors), and different wavelength values do not affect the measurement results (although they may affect the calibration coefficients).
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Figure 1 |
2. Distributed FBG Sensors Need FBGs with Multiple Wavelengths
The main reason for customizing specific wavelengths is often due to the wavelength limitations of the FBG demodulator or the network application requirements of the FBG sensors.
Furthermore, in single distributed FBG sensors (also known as series FBG sensors or array FBG sensors), different FBG should have different wavelengths and sufficient spacing between them without overlap. If they are placed in different channels of the FBG demodulator, the same wavelength can be used.
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Figure 2 |
Double-ended OFSCN® Capillary Seamless Steel Tube FBG Sensors can also be used in series for the measurement of multiple physical quantities or mixed measurements (stress, strain, and temperature). In this case, each sensor needs to be customized with a different wavelength to distinguish different reflection wavelengths.
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Figure 3 |
OFSCN® Capillary Seamless Steel Tube FBG Sensors produced by DCYS typically have a standard wavelength range near the C-band (approximately between 1525nm and 1565nm). Other wavelength products can be customized according to customer requirements.
Our philosophy is: "OFSCN®, make optical fiber stronger!"
DCYS is a professional wavelength-customized Fiber Bragg Grating sensor manufacturer, providing customized wavelength FBG temperature sensors, C-band center wavelength FBG stress-strain sensors and other information; the brand of FBG sensors with customizable wavelengths is "OFSCN".