Yanbiao Liao

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Three multiplexing schemes are presented for polarization-maintaining photonic crystal fiber based Sagnac interferometric sensors. The first technique is wavelength division multiplexing using coarse wavelength division multiplexers (CWDMs) to distinguish signals from each multiplexed sensor in different wavelength channels. The other two schemes are to(More)
In-fiber polarimeters or polarization mode interferometers (PMIs) are fabricated by cascading two CO2-laser-induced in-fiber polarizers along a piece of hollow-core photonic bandgap fiber. Since the two interfering beams are the orthogonal polarizations of the fundamental mode, which are tightly confined to the core and have much lower loss than higher(More)
A new method, based on the shift of light power transmitted through fiber, to measure corrosion of aluminum is presented. A multimode fiber was metallized by use of physical vacuum to deposit aluminum onto an unclad part of a fiber of 1 to 2 cm length. Scanning-electron microscopy and x-ray diffraction were used to show, the formation and corrosion of the(More)
We present a new method for monitoring aluminum corrosion by determining the kind of light output that is as corrosion occurs. We prepared some metallized multimode optical fibers by physical vacuum deposition of aluminum to monitor metal corrosion. The sensing area was 1-2 cm in length and had an uncladded part. We used scanning-electron microscopy (SEM)(More)
The parameters of the semiconductor laser source are vital for the performances of optical coherent systems. In this paper, a novel method to measure the phase-shift φm between laser central optical-frequency modulation (COFM) and the accompanied optical-intensity modulation (AOIM) is proposed, which is easy to realize and requires no further fiber etalons(More)
We present a new hydrogen sensor system based on the use of an optical fiber extrinsic Fabry-Perot interferometer coated with palladium silver (Pd-Ag) film. The sensing mechanism of such a sensor is based on the mechanical stress that is induced in the Pd-Ag film when it absorbs hydrogen. To obtain the absolute length of the air gap, a modified(More)
High-quality three-dimensional photonic crystal (PC) heterostructures were fabricated using the modified self-assembly method, and their structural and optical properties were analyzed. Results suggest that the optical quality of heterostructures formed by depositing bigger particles on small ones is superior to that of heterostructures formed by stacking(More)
A method for testing the physical and optical properties of hydrogel thin films is reported based on using long-period fiber gratings. For humidity levels from 50% to 70% RH, a wavelength decrease of 11.0 nm is observed, with a sensitivity of 0.6 nm/%RH. For humidity levels from 70% to 98% RH, a wavelength increase of 6.3 nm is seen, with a sensitivity of(More)
We measured the hydrostatic pressure dependence of the birefringence and birefringent dispersion of a Sagnac interferometric sensor incorporating a length of highly birefringent photonic crystal fiber using Fourier analysis. Sensitivity of both the phase and chirp spectra to hydrostatic pressure is demonstrated. Using this analysis, phase-based measurements(More)