| The symmetrical metal-cladding waveguide (SMCW) is a special optical waveg-uide structure, which typically consists of a guiding layer and two metal-claddinglayers. Compared to traditional dielectric waveguides, the SMCW obtains a broaderrange of effective refractive index (RI), i.e. from zero to the RI of guiding layer, whichenables direct coupling of light energy from free space into the waveguide. Ultrahigh-order modes can be excited in the SMCW with a submillimeter scale of the guidinglayer, which are highly sensitive to the waveguide parameters. This dissertation in-vestigates the technique of polarization beam splitting (PBS) and the application ofGoos-H¨anchen (GH) effect based on the SMCW structure.The reffection and transmission properties of the SMCW show that the couplingof light energy at the guided mode resonance can be enhanced by choosing properparameters of the waveguide, which helps to improve the transmissivity. Birefrin-gent material is utilized as the coupling layer of SMCW, and hence the guided moderesonance will not be simultaneously excited by TE and TM polarizations. Light en-ergy of the polarization which induces the excitation of guided mode is transmittedthrough the waveguide structure, while that of the polarization which does not exciteguided mode resonance is almost reffected. As a result, the two orthogonally polarizedbeams are spatially separated. Moreover, by introducing electro-optic material intothe guiding layer of SMCW, the resonance condition of the ultrahigh-order mode isdramatically changed due to electrical modulation of the guiding layer parameters,which gives rise to the tuning of PBS.Theoretical analysis indicates that the GH effect is closely related to the intrinsicand radiative dampings of the waveguide. We select proper waveguide parameters, which makes the two dampings of SMCW approach to the best matching conditionand finally results in great enhancement of the GH shift. We carry on an investigationin the application field based on the enhanced GH effect as well as the high sensitivityof ultrahigh-order modes.The SMCW exhibits a strong spatial dispersion effect, i.e. the superprism ef-fect, at the excitation of ultrahigh-order mode. The wave vector presents completelydifferent characteristics of dispersion in the directions parallel and perpendicular tothe interface, which induces a separation of slightly different wavelengths and then anotable change of the reffected beam displacement. It is experimentally demonstratedthat the lateral shift of reffected beam reaches 900μm within a variation of 0.15nm inwavelength, which shows a spatial dispersion ability much stronger than that of otherthin-film structures. The GH effect is also used for wavelength sensing, the resolutionof which reaches 0.2pm near the wavelength of 860nm in experiment. Besides, theLiNbO3 crystal is introduced to the guiding layer of SMCW for the control of GHshift, owing to the electro-optic and piezoelectric effects. Experimental result showsthat the electric control of the lateral beam shift is realized in a range of 720μm.An oscillating wave sensor based on the SMCW structure is also proposed, whichutilizes the enhanced GH effect for RI sensing. The guiding layer of the sensor, whichlocates at the region of oscillating field, works as the sample cell. The sensing eff-ciency is largely improved due to strong confinement of energy. Besides, ultrahigh-order modes are far more sensitive to the RI of guiding layer than low-order modes.Moveover, high stability and anti-jamming ability are obtained since the means of GHshift for RI sensing helps to avoid the effect of light intensity ffuctuation, which isprobably caused by instability of the laser and perturbation of the environment. Aseries of NaCl solutions with equal gradient of concentration is used as sample analytefor experimental measurement, which reaches a RI resolution of 2.0×10ff7 RIU.
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