Prism coupler sensor

Lukosz, W. Tiefenthaler, K., Sensitivity of integrated optical grating and prism couplers as (bio) chemical sensors, Sens. Actuators B 1988, 15, 273 284... 

Homola, J., Koudela, I., and Yee, S. S. (1999). Surface Plasmon resonance sensor based on diffraction gratings and prism couplers sensitivity comparison. Sens. Actuators B 54 16-24. 

Fig. 5 Instrumental contribution to sensitivity S0r/Sn f as a fimction of wavelength for SPR sensors with angular modulation and prism coupler or grating coupler and three different grating periods. Prism-hased sensor configuration BK7 glass prism, gold film, and a non-dispersive dielectric (refractive index 1.32). Grating-based sensor configuration a non-dispersive dielectric (refractive index 1.32) and gold grating...

The instrumental contribution to sensitivity of SPR sensors using prism couplers ( 5 r/5 ef)pj. jj is primarily determined by the second term in... 

Fig. 14 The maximum bulk refractive index sensitivity as a function of wavelength for SPR sensors with intensity modulation and a prism coupler exciting a conventional sim-face plasmon (SP) at the interface of gold and a non-dispersive dielectric (refractive index 1.32) and coupled symmetric (SSP) and antisymmetric (ASP) surface plasmons on a thin gold film (thickness 20 nm) simroimded by two identical non-dispersive dielectrics (refractive index 1.32)...

SPR Sensors Based on Prism Couplers and Angular Modulation. 99... 

In the optical system of an SPR sensor, surface plasmons are optically excited and the SPR signal is encoded into a light wave interacting with the surface plasmons. Based on the method of excitation of surface plasmons, SPR sensors can be classified as SPR sensors based on (i) prism couplers, (ii) grating couplers, and (iii) waveguide couplers (Fig. 4). 

Most of the SPR sensors reported to date are based on prism couplers. Prism coupHng of fight into surface plasmons is convenient and can be realized with simple and conventional optical elements. It can be readily combined with any type of modulation. Specific examples of prism-based SPR sensors are discussed below. 

Fig. 4 SPR sensors based on a prism couplers, b grating couplers, and c waveguide couplers...

In 1988 Matsubara et al. reported an SPR sensor based on prism coupler and angular modulation [18]. The optical system of their sensor is shown in Fig. 5. 

Although to date grating couplers have been used in SPR to a lesser extent than have prism couplers, they offer some very attractive features. Most importantly, as gratings can be fabricated by techniques such as replication into plastic substrates, grating-based SPR chips provide an avenue to low-cost SPR sensors. 

Homola J, Koudela I, Yee SS, Surface plasmon resonance sensors based on diffraction gratings and prism couplers Sensitivity comparison, Sensor Actual. B Chem. 1999 54 16-24. 

Figure 5. Experimental measurement of porous silicon waveguide resonance after several functionalization steps and exposure to either (a) complimentary DNA, (b) non-complimentary DNA, or (c) buffer solution. The small shift due to DNA hybridization is easily within the resolution of the prism coupler rotation stage of0.002°. (d) Histogram summarizing the selectivity of the porous silicon waveguide sensor to 24 base pair DNA. DNA hybridization (complimentary DNA shift) can be clearly distinguishedfrom the low level of non-specific binding (mismatch DNA shift) and the noise floor of the measurement system...

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