Why do FBG sensors typically operate at 1550nm (C-band)?
FBG sensors typically operate at 1550 nm (C-band) primarily for three technical reasons:
- Lowest Optical Attenuation: Standard single-mode optical fibers exhibit the lowest optical power loss in the 1550 nm wavelength region, typically around 0.2 dB/km. This minimizes signal degradation, enabling longer sensing distances and more robust measurements.
- Component Maturity and Cost-Effectiveness: The 1550 nm band is a cornerstone of the telecommunications industry. This has led to the development of a highly mature and cost-effective ecosystem of optical components, including lasers, detectors, and interrogators, which are readily available and optimized for performance in this wavelength range.
- Wavelength Division Multiplexing (WDM) Capability: The C-band offers a sufficiently broad spectral window, typically 40 nm (1525 nm to 1565 nm), to effectively implement WDM. This allows multiple FBG sensors, each reflecting a unique wavelength, to be multiplexed onto a single optical fiber, significantly increasing the number of measurement points per fiber.
OFSCN® offers a range of fiber Bragg gratings and packaged sensors that operate within this optimized wavelength window:
- OFSCN® Polyacrylate Fiber Bragg Gratings / Fiber Bragg Grating Strings (bare)
- OFSCN® Polyimide Fiber Bragg Gratings / Fiber Bragg Grating Strings (bare)
- Our packaged sensors, such as the OFSCN® 300°C Fiber Bragg Grating Temperature Sensor, also utilize FBGs operating in this advantageous spectral range.