An all-fiber acousto-optic tunable bandpass filter has been proposed and experimentally demonstrated by fabricating a lateral offset fiber splicing structure between the lead-in single-mode fiber and acoustic fiber grating. In the presence of acoustic fiber grating that enables the coupling between the antisymmetric cladding modes and symmetric fundamental core mode, the proposed bandpass filter shows a broadband tunable wavelength range up to 152.9 nm with a wavelength tuning sensitivity of À206.07 nm/MHz through adjusting the acoustic frequency. Further experimental results indicate that by using HF acid to etch part of the fiber cladding, the largest tunable bandpass wavelength range could be expanded to 210.2 nm with an improved wavelength tuning sensitivity of À256.89 nm/MHz. Moreover, by adjusting the applied RF signal voltage, a dynamic peak transmission range in a magnitude of $10 dB have been experimentally achieved.Index Terms: Acousto-optic tunable filter (AOTF), optical bandpass filter, acoustic fiber grating, offset fiber splicing.
A dual-parameter sensor based on a fiber-optic interferometer consisting of a non-adiabatic fiber taper and a long-period fiber grating (LPFG) integrated with magnetic nanoparticle fluids has been proposed and experimentally demonstrated. Due to the Mach–Zehnder interference induced by the concatenation of the fiber taper and long-period grating, an interferometric spectrum could be acquired within the transmission resonance spectral envelope of the LPFG. Thanks to different magnetic field and temperature sensitivities of difference interference dips, simultaneous measurement of the magnetic field intensity and environmental temperature could be achieved. Moreover, due to the variation in coupling coefficients of the fiber taper and the LPFG in response to the change of the applied magnetic field intensity, some of the interference dips would exhibit opposite magnetic-field-intensity-dependent transmission loss variation behavior. Magnetic field intensity and temperature sensitivities of 0.017 31 dB Oe−1 and 0.0315 dB K−1, and −0.024 55 dB Oe−1 and −0.056 28 dB K−1 were experimentally acquired for the experimentally monitored interference dips.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.