Tunable narrow-band source using a VCSEL and an EDFA for interrogation of fiber Bragg grating sensors

Abstract

Wavelength tuning with a current of a long-wavelength vertical-cavity surface-emitting laser (VCSEL) with a spectral line width of 30 MHz was studied. To stabilize the power, saturated amplification of the VCSEL output by an erbiumdoped fiber amplifier (EDFA) was performed. For wavelength tuning by 2.5 nm, there was a 3-fold change in the VCSEL output power; however, the variation in the amplified output power was within ±13%. For wavelength tuning of 4 nm, the variation was ±20%. Application to fiber Bragg grating sensor interrogation was discussed.