David Monzón-Hernández

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We propose the use of tapered microstructured fibers with collapsed air-holes coated with thin layers for gas sensing. The collapsing of the holes allows having access to the evanescent fields which can be absorbed or attenuated with gas-permeable thin films. On the other hand, a section of the holey fiber is transformed into a solid multimode fiber. The(More)
The use of large-mode-area tapered holey fibers with collapsed air holes for refractive index sensing is demonstrated. The collapsing of the holes is achieved by tapering the fibers with a "slow-and-hot" method. This non adiabatic process makes the core mode to couple to multiple modes of the solid taper waist. Owing to the beating between the modes the(More)
A large-mode-area holey fiber was tapered to a point in which the airholes collapsed, and its dependence on temperature and strain was studied. The transmission spectrum of such a fiber exhibits a series of peaks owing to the interference between the modes of the solid taper waist. We found that the interference peaks shifted to shorter wavelengths as the(More)
We report the fabrication and modeling of single-mode tapered optical fiber sensors. The fabrication technique consist of stretching a section of fiber with an oscillating flame torch. Such a process allows controllable fabrication of lossless tapered fibers with a uniform waist. The sensor transmittance is modeled with a simple ray optics approach. In the(More)
The use of uniform-waist cladded multimode tapered optical fibers is demonstrated for evanescent wave spectroscopy and sensors. The tapering is a simple, low-loss process and consists of stretching the fiber while it is being heated with an oscillating flame torch. As examples, a refractive-index sensor and a hydrogen sensor are demonstrated by use of a(More)
We report a miniature hydrogen sensor that consists of a subwavelength diameter tapered optical fiber coated with an ultra thin palladium film. The optical properties of the palladium layer changes when the device is exposed to hydrogen. Consequently, the absorption of the evanescent waves also changes. The sensor was tested in a simple light transmission(More)
We report on an optical fiber surface plasmon resonance sensor that exhibits multiple resonance peaks. The sensor is based on a uniform-waist single-mode tapered fiber coated on one side with a thin metal layer. Owing to the asymmetry of the sensor structure, the different hybrid surface plasmon modes supported by the semicircular layer can be excited by(More)
We propose a microfluidic method to measure the refractive index of liquids. This method is based on the dynamic focusing by a capillary when liquids with different refractive indexes are inserted into it. Fabrication of such a refractometer has been done by encapsulating two fibers and a capillary. A calibration method is proposed.
We report on a functional optical microfiber mode interferometer and its applications for absolute, temperature-insensitive refractive index sensing. A standard optical fiber was tapered down to 10 μm. The central part of the taper, i.e., the microfiber, is connected to the untapered regions with two identical abrupt transitions. The transmission spectrum(More)
A low-loss, compact, and highly sensitive optical fiber curvature sensor is presented. The device consists of two identical low-loss fused fiber tapers in tandem separated by a distance L. When the optical fiber is kept straight and fixed, no interference pattern appears in the transmitted spectrum. However, when the device is bent, the symmetry of the(More)