Fiber-facet-integrated guided-mode resonance filters and sensors: experimental realization

Abstract

Guided-mode resonant (GMR) thin films integrated on fiber tips are known to realize compact filters and sensors. However, limited progress in experimental realization has been reported to date. Here we provide a considerable advance in this technology, as we experimentally demonstrate efficient fiber-facet mounted device prototypes. To retain a large aperture for convenient coupling, we design and fabricate silicon nitride-based resonators on the tip of a multimode fiber. We account for light propagation along the multimode fiber with exact numerical methods. This establishes the correct amplitude and phase distribution of the beam incident on the tip-mounted GMR element, thus enabling us to properly predict the resonance response. To fabricate the integrated GMR structures on the tips of fibers, we employ standard microfabrication processes, including holographic interference lithography and reactive-ion etching. The experimental results agree with simulation with an example device achieving high efficiency of ∼77% in transmission. To investigate fiber sensor operation, an etched silicon nitride fiber tip filter is surrounded with solutions of various refractive indices, yielding an approximate sensitivity of 200 nm/RIU.

Polymer-Based Guided-Mode Resonance Sensors: From Optical Theories to Sensing Applications

“…Polymer-based GMR devices are implemented in different optical sensing applications mainly for the ease of the fabrication process, particularly nanoimprinting. For instance, a GMR device is constructed on a cleaver tip of glass optical fiber. , The fabrication approach follows the configuration shown in Figure c. Here, the polymer medium used is SU-8 2000 with a refractive index of 1.6.…”

“…For instance, a GMR device is constructed on a cleaver tip of glass optical fiber. 15,84 The fabrication approach follows the configuration shown in Figure 3c. Here, the polymer medium used is SU-8 2000 with a refractive index of 1.6.…”

Semiconductor Multimaterial Optical Fibers for Biomedical Applications

“…For instance, hydrogen gas sensors can be fabricated using ITO nanoparticle coating [ 41 ], sulfide gas sensors can be fabricated using zinc oxide nanorods coating [ 45 ], and PH [ 46 ] and relative humidity [ 43 ] sensors can be fabricated utilizing polymeric coatings of polyallylamine hydrochloride (PAH) and poly-acrylic acid (PAA). The prevalence and usability of basic fibers stimulate the development of techniques and technologies for integrating photonic devices directly onto them [ 47 ].…”

Design of Fiber-Tip Refractive Index Sensor Based on Resonant Waveguide Grating with Enhanced Peak Intensity

“…In their work from 2000 [22], Wawro and Magnusson demonstrated a ~18% transmittance notch obtained with silicon nitride (Si 3 N 4 ) grating films and deposited on a fiber tip using interference lithography, although the read-out of the signal was difficult because of the high level of background noise. Later, in 2018, regarding enhanced peak intensity, the same group reported the realization of an improved fiber-tip RWG sensor based on a multi-mode fiber (MMF) with the collection of the transmitted signal [23].…”