Scalable wafer-to-fiber transfer method for lab-on-fiber sensing

Abstract

We present an efficient and flexible method to realize micro- and nano-optical structures on the tip of optical fibers. We demonstrate this approach for a fiber-tip sensor consisting of a photonic crystal (PhC) structure in a semiconductor membrane on the cleaved facet of a telecom fiber. The PhC structure is fabricated on a wafer by lithography and etching and then transferred to the fiber facet by a simple mechanical pickup process through an opening in the substrate, without the need for adhesives or a micromanipulator. Due to its reliability, scalability, and the use of wafer-scale fabrication methods, this process increases the possibilities for fiber-tip applications at the industrial level. With the fabricated fiber tip sensors, we demonstrate sensing of the refractive index and temperature, with resonance wavelength shifts of 120 nm/RIU and 95 pm/K, respectively.

Temperature-Compensated Solution Concentration Measurements Using Photonic Crystal Fiber-Tip Sensors

“…For this work, PhC structures with a hexagonal lattice were patterned on a 250 nm thick InP membrane, which is separated from a InP substrate by a 300 nm thick sacrificial InGaAs layer, following the fabrication methods described in [ 20 ]. Briefly, the photonic crystal is patterned on the InP membrane by electron beam lithography (EBL) followed by inductively coupled plasma reactive ion etching (ICP-RIE), using a SiN layer as a hard mask.…”

“…The proposed sensor probe is based on photonic crystal (PhC) fiber-tip sensors. Each sensor is assembled with a simple and controllable method, where a 2D photonic crystal is fabricated on a wafer by standard semiconductor fabrication methods, and then it is mechanically transferred to the fiber end-face [ 20 ]. This transfer method only requires a movable stage and a microscope camera, and different to similar techniques, it does not need adhesives or additional materials to maintain the PhC attached to the fiber.…”

“…This transfer method only requires a movable stage and a microscope camera, and different to similar techniques, it does not need adhesives or additional materials to maintain the PhC attached to the fiber. These devices have shown a strong spectral response in reflection, and their applicability in temperature and refractive index sensing has been demonstrated [ 20 ]. While one of these sensors can be used to measure the solution’s refractive index, which is correlated to the ethanol concentration in the liquid mixture, its sensitivity to temperature needs to be compensated.…”

Low‐Temperature Synthesis of Silicon Oxynitride‐Doped Si for Tunable Bragg Gratings Homogeneously Deposited on Si, SiO2, and Borosilicate Substrates and the tip of SM and PM Optical Fibers

“…[15] This occurs due to an increase in the hydrogen content in silicon oxynitrides similar to hydrogenated amorphous silicon (a-Si:H) and also leads to a decrease in the optical bandgap. [16] Due to the small size, lightweight, and strong antielectromagnetic interference ability of optical fibers, some approaches [17] to transfer the micro-and nano-optical structures to the optical fiber facets were demonstrated and successfully used in spectral sensing. [18] One report studied the direct deposition of BGs on asingle-mode fiber (SMF) using electron beam deposition technique, nevertheless, the study was demonstrated for the single application wavelength with the reflection values of 50-80% (3-7 dB respectively).…”

All‐Fiber Optical Waveform Converter Based on Deformed Catenary Nanostructure

“…[1] Most traditional optical devices use the difference of refractive index of materials to construct a certain spatial structure shape to change the wavefront state [2,3] and then realize the manipulation of the optical field. In contrast, the "Lab-on-Fiber" technology can accurately manipulate the wavefront phase, polarization state, and environmental parameters through the microstructure on the side, [4,5] fiber end, [6,7] or inner, [8,9] so it has the characteristics of small size, flexible structure, dispersion-flattened, low transmission loss, and good biocompatibility. Especially in recent years, with the rapid development of metasurface technology, [10] scientists have integrated metasurface on optical fiber.…”