Stability of erbium-doped fiber laser for high pressure measurement: Ring vs linear cavity

The application of optical fiber sensor in fields such as heavy industries has to greater extent become very important as the optical sensors is immune to EMI. This paper presented a stable high pressure sensor using an erbium-doped fiber laser (EDFL). The pressure sensor head is made of fiber Bragg grating (FBG) encased in stainless steel housing to withstand high pressure of up to 10bar. The stability of the sensing system is measured over 30 minutes and the result shows about 1.50% and 0.41% variation of peak output power for ring and linear respectively. In addition, the wavelength variation for ring is 1.16% and there is no significant variation linear configuration.