| 1. |
- Bora, Tanujjal, et al.
(författare)
-
Controlled side coupling of light to cladding mode of ZnO nanorod coated optical fibers and its implications for chemical vapor sensing
- 2014
-
Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 202, s. 543-550
-
Tidskriftsartikel (refereegranskat)abstract
- Controlled light coupling from surrounding to the cladding mode of zinc oxide (ZnO) nanorod coated multimode optical fiber induced by the light scattering properties of the nanorod coating and their applications of sensing are reported here. A dense and highly ordered array of ZnO nanorods is grown on the cladding of silica fibers by using low temperature hydrothermal process and the effect of the hydrothermal growth conditions of the nanorods on the light scattering and coupling to the optical fibers is experimentally investigated. The nanorod length and its number per unit area are found to be most crucial parameters for the optimum side coupling of light into the fibers. Maximum excitation of the cladding mode by side coupling of light is obtained with ZnO nanorods of length similar to 2.2 mu m, demonstrating average coupling efficiency of similar to 2.65%. Upon exposure to different concentrations of various chemical vapors, the nanorod coated fibers demonstrated significant enhancement in the side coupled light intensity, indicating the potential use of these ZnO nanorod coated fibers as simple, low cost and efficient optical sensors. The sensor responses to methanol, ethanol, toluene and benzene vapor were investigated and compared, while the effect of humidity in the sensing environment on the sensor performance was explored as well.
|
|
| 2. |
- Fallah, H., et al.
(författare)
-
Demonstration of side coupling to cladding modes through zinc oxide nanorods grown on multimode optical fiber
- 2013
-
Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 38:18, s. 3620-3622
-
Tidskriftsartikel (refereegranskat)abstract
- A novel concept is introduced that utilizes the scattering properties of zinc oxide nanorods to control light guidance and leakage inside optical fibers coated with nanorods. The effect of the hydrothermal growth conditions of the nanorods on light scattering and coupling to optical fiber are experimentally investigated. At optimum conditions, 5% of the incident light is side coupled to the cladding modes. This coupling scheme could be used in different applications such as distributed sensors and light combing. Implementation of the nanorods on fiber provides low cost and controllable nonlithography-based solutions for free space to fiber coupling. Higher coupling efficiencies can be achieved with further optimization.
|
|
| 3. |
- Fallah, Hoorieh, et al.
(författare)
-
Excitation of core modes through side coupling to multimode optical fiber by hydrothermal growth of ZnO nanorods for wide angle optical reception
- 2014
-
Ingår i: Journal of the Optical Society of America. B, Optical physics. - : Optical Society of America. - 0740-3224 .- 1520-8540. ; 31:9, s. 2232-2238
-
Tidskriftsartikel (refereegranskat)abstract
- Side coupling to core modes through zinc oxide (ZnO) nanorods grown around the fiber is demonstrated in this work. The scheme utilizes wet etching of the cladding region followed by hydrothermal growth of the nanorods. The combination of nanostructures and the optical fiber system is used to demonstrate a simple wide field of view (FOV) optical receiver. Core modes are excited by the light scattered in the region where the fiber core is exposed. The angular response of the receiver was tested using a nephlometer. Light coupling efficiency was extracted by deconvoluting the finite beam extinction from the measured power. The results were compared to a first-order analytical model in which the phase function is assumed to linearly shift with the incident angle. The trend of the experimental measurements agrees with the model. 180 degrees FOV is verified, and maximum coupling efficiency of around 2.5% for a single fiber is reported. Excitation of core modes through side coupling shows potential for the application of these devices in optical receivers and sensors.
|
|
