Femtosecond Laser Inscription Technology for FBGs

Are gratings inscribed by femtosecond lasers more resistant to high temperatures than traditional UV-inscribed ones?

Yes, gratings inscribed by femtosecond lasers, such as the OFSCN® Standard Femtosecond Fiber Bragg Gratings / Fiber Bragg Grating Strings (Bare), generally exhibit significantly higher temperature resistance compared to traditional UV-inscribed FBGs.

Technical Explanation:

Femtosecond laser inscription is a point-by-point writing process that does not damage the fiber’s coating. When inscribed on standard OFSCN® SM Polyimide Optical Fiber, these gratings can achieve a maximum operating temperature range of -270℃ to 800℃ (with special processing).

In contrast, traditional UV-inscribed FBGs typically have lower temperature limits:

  • OFSCN® Polyacrylate Fiber Bragg Gratings / Fiber Bragg Grating Strings (bare) (UV-inscribed) have an available temperature range of -40℃ to 100℃.
  • OFSCN® Polyimide Fiber Bragg Gratings / Fiber Bragg Grating Strings (bare) (UV-inscribed) have an available temperature range of -200℃ to 300℃.

This enhanced temperature resistance of femtosecond FBGs is crucial for applications in extreme high-temperature environments.

Here is an image of a bare FBG:

https://www.ofscn.net/images/53/190719-768/250-FBG.jpg

You can find more detailed technical parameters for femtosecond FBGs here:
OFSCN® Standard Femtosecond Fiber Bragg Gratings / Fiber Bragg Grating Strings (Bare)

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