Characteristics of the heat resistant FBG sensor under laser cladding condition

Nishimura, Akihiko  ; Terada, Takaya

We proposed FBG sensor made by femtosecond laser processing could be the best candidate. Combination with fabric reinforcement and heatproof adhesive mold protected fragile optical fiber. To make the best use, we fixed the FBG sensor by metal mold. A groove was processed to a SUS metal plate with a grindstone. We used a Quasi-CW laser to weld a filler wire on plate. The optical fiber set under the filler wire beforehand was heated by the laser pluses with 10 J and 10 ms, partially to be soaked in a weld pool. A series of weld pool formed a sealing clad on the groove. The FBG sensor was buried at 2 mm depth over the length of 1 cm. No degradation on its reflection spectra was detected before and after the processing. The FBG sensor can detect the vibration of the plate caused by impact shocks. In this paper, Bragg peak shift of the FBG sensor under laser cladding condition has been discussed.