Optical characterization of refractive index sensors based on planar waveguide Fabry-Perot Bragg grating cavity

2013 ◽  
Author(s):  
Sang-Mae Lee ◽  
Wan-Taek Jeong ◽  
Kyung-Chun Kim ◽  
Kyung-Jo Kim ◽  
Mincheol Oh ◽  
...  
2013 ◽  
Vol 7 (1) ◽  
pp. 073792 ◽  
Author(s):  
Sang-Mae Lee ◽  
Won-Taek Jeong ◽  
Kyung-Chun Kim ◽  
Kyung-Jo Kim ◽  
Mincheol Oh ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2981 ◽  
Author(s):  
Dorian Minkov ◽  
George Angelov ◽  
Radi Nestorov ◽  
Aleksey Nezhdanov ◽  
Dmitry Usanov ◽  
...  

Three AsxTe100−x films with different x and dissimilar average thickness d ¯ are characterized mainly from one interference transmittance spectrum T(λ = 300 to 3000 nm) of such film on a substrate based on the advanced optimizing envelope method (AOEM). A simple dual transformation of T(λ) is proposed and used for increasing the accuracy of computation of its envelopes T+(λ) and T−(λ) accounting for the significant glass substrate absorption especially for λ > 2500 nm. The refractive index n(λ) of As40Te60 and As98Te2 films is determined with a relative error <0.30%. As far as we know, the As80Te20 film is the only one with anomalous dispersion and the thickest, with estimated d ¯ = 1.1446 nm, ever characterized by an envelope method. It is also shown and explained why the extinction coefficient k(λ) of any of the three AsxTe100−x films is computed more accurately from the quantity Ti(λ) = [T+(λ)T−(λ)]0.5 compared to its commonly employed computation from T+(λ). The obtained results strengthen our conviction that the AOEM has a capacity for providing most accurate optical characterization of almost every dielectric or semiconductor film with d ¯ > 300 nm on a substrate, compared to all the other methods for characterization of such films only from T(λ).


Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 306 ◽  
Author(s):  
Paulina Listewnik ◽  
Marzena Hirsch ◽  
Przemysław Struk ◽  
Matthieu Weber ◽  
Mikhael Bechelany ◽  
...  

We report the fabrication of a novel fiber-optic sensor device, based on the use of a microsphere conformally coated with a thin layer of zinc oxide (ZnO) by atomic layer deposition (ALD), and its use as a refractive index sensor. The microsphere was prepared on the tip of a single-mode optical fiber, on which a conformal ZnO thin film of 200 nm was deposited using an ALD process based on diethyl zinc (DEZ) and water at 100 °C. The modified fiber-optic microsphere was examined using scanning electron microscopy and Raman spectroscopy. Theoretical modeling has been carried out to assess the structure performance, and the performed experimental measurements carried out confirmed the enhanced sensing abilities when the microsphere was coated with a ZnO layer. The fabricated refractive index sensor was operating in a reflective mode of a Fabry–Pérot configuration, using a low coherent measurement system. The application of the ALD ZnO coating enabled for a better measurement of the refractive index of samples in the range of the refractive index allowed by the optical fiber. The proof-of-concept results presented in this work open prospects for the sensing community and will promote the use of fiber-optic sensing technologies.


2013 ◽  
Vol 677 ◽  
pp. 363-367
Author(s):  
Yuri N. Kulchin ◽  
Oleg B. Vitrik ◽  
Stanislav O. Gurbatov

The phase of light propagating through a bent optical fibre is shown to depend on the refractive index of the medium surrounding the fibre cladding when there is resonance coupling between the guided core mode and cladding modes. This shifts the spectral maxima in the bent fibre-optic Fabry–Perot interferometer. The highest phase and spectral sensitivities achieved with this interferometer configuration are 0,71 and 0,077, respectively, and enable changes in the refractive index of the ambient medium down to 5∙10–6 to be detected. This makes the proposed approach potentially attractive for producing highly stable, precision refractive index sensors capable of solving a wide range of liquid refractometry problems.


2016 ◽  
Vol 851 ◽  
pp. 199-204 ◽  
Author(s):  
Veronika Schmiedova ◽  
Jan Pospisil ◽  
Oldrich Zmeskal ◽  
Viliam Vretenar

The paper deals with the study of optical properties of graphene oxide (GO) by inkjet printing. Defined structure of GO can be obtained by reducing of prepared layers either by heating or by UV radiation (rGO). The dispersion function for refractive index and extinction coefficient of GO and both rGO thin films were measured by spectroscopic ellipsometry in the wavelength range of 200 – 850 nm. Spectroscopic ellipsometry (SE) was used characterize the optical response of layer of GO reduced by UV and thermal reduction GO in visible range.


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