Compact integrated optical sensor system

2007

The paper presents the results of theoretical analysis as well as the results of experimental research involving planar sensor structures with input grating couplers of the period Λ = 800 nm. In the theoretical part of the paper we discussed the influence of the parameters of a sensor structure on it sensitivities. The experimental part of the work presents the results of experimental research involving the influence of refractive index of the cover on the coupling characteristics of sensor structures with grating couplers. The full widths at half maximum (FWHM) were from 0.023° to 0.029°. For the investigated structures we estimated detection thresholds for the changes of refractive index of the cover and the changes of sensitive film thickness. It has been demonstrated that by the application of the elaborated structures we can detect minimal changes of the refractive index (Δnc)min = 2.1×10−6 when the refractive index of the cover nc = 1.333 and (Δnc)min = 1.0×10−6 when nc = 1515. For sensitive films of the thickness w < 100 nm, by using the elaborated structures, we can detect mean changes of the thickness along the values lower than 10−3 nm.

Section: Introductionmentioning

confidence: 99%

Sensor properties of planar waveguide structures with grating couplers

2007

“…The said effects bring about the change of effective refractive in− dexes of modes propagating in the structure. The changes of effective refractive indexes can be measured by the applica− tion of the interferometers of Mach−Zehnder [4,5], Young [6,7] and with a polarimeter [1,[8][9][10] or grating couplers [3,[11][12][13][14][15][16][17][18]. In chemical and biochemical measurements, surface plasmon resonance sensors are also applied [19,20].…”

Section: Introductionmentioning

confidence: 99%

“…Grating couplers as sensor ele− ments were for the first time applied by the research team led by Lukosz [11,12]. The application of grating couplers for sensor application has been also intensively investigated by Kuntz et al [13][14][15], and by Vörös, Szendrö, and Horváth [16,17]. Commercial measurement systems based on input grating couplers are already available [18].…”

Section: Introductionmentioning

confidence: 99%

Embossable grating couplers for planar evanescent wave sensors

2011

The paper presents input grating couplers to be applied in planar evanescent wave sensors. Waveguide films SiO2:TiO2 were obtained using the sol-gel method, and grating couplers with a groove density of 1000 g/mm and 2400 g/mm were produced using the method of master grating embossing in sol film. The influence of refractive index of the cover on incoupling angles was presented. Basing on the experimental results, detection limits involving the changes of effective indexes and refractive indexes of the cover for the investigated planar structures were determined. Sensor structures with the couplers having a groove density of 1000 g/mm enable to detect minimum changes of the effective index below 3.3×10−7 and to detect minimum changes of refractive index of the cover below 2.3×10−6. Detection limits for the structures with couplers having the groove density of 2400 g/mm are over twofold higher.

“…The said effects bring about the change of effective refrac− tive indexes of modes propagating in the structure. The changes of effective refractive indexes can be measured by the application of the interferometers of Mach−Zehnder [5][6][7], Young [8,9], Michelson [10] and with a polarimeter [2,11,12] or grating couplers [3,[13][14][15][16][17][18][19][20][21][22]. Due to technologi− cal constraints (the interaction length is limited to single centimetres), the operating range in PEWS is most fre− quently limited to a single interference fringe.…”

Section: Introductionmentioning

confidence: 99%

Optical uniform/gradient waveguide sensor structure - characterization

2011

The paper presents the characterization of a composite uniform/gradient waveguide sensor structure. The results of theoretical analysis and experimental studies have been presented. The influence of sensor structure parameters on homogenous sensitivity and on surface sensitivity has been analyzed. Gradient layers for composite sensor structures were produced using the ion-exchange method, and the uniform layers, using the sol-gel method. In the experimental studies, involving the produced sensor structures, a prism coupler and a grating coupler were applied. Excellent agreement between the results of theoretical analysis and experimental studies has been achieved.