We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the direct coupling method yield high optical intensity at resonance, which is different from the conventional strategy to create localized “hot spots.” The observed excitation efficiency of the Raman signal is significantly enhanced, owing to the high Q factor of the resonant cavity. Furthermore, effective modulation of the Raman intensity is available by adjusting the polymethyl methacrylate (PMMA) thickness in the guiding layer, i.e., by tuning the light–matter interaction length. A large modulation depth is verified through the fact that 10 times variation in the enhancement factor is observed in the experiment as the PMMA thickness varies from 7 to 23 μm.

The photonic spin Hall effect (SHE) has been intensively studied and widely applied, especially in spin photonics. However, the SHE is weak and is difficult to detect directly. In this paper, we propose a method to enhance SHE with the guided-wave surface-plasmon resonance (SPR). By covering a dielectric with high refractive index on the surface of silver film, the photonic SHE can be greatly enhanced, and a giant transverse shift of horizontal polarization state is observed due to the evanescent field enhancement near the interface at the top dielectric layer and air. The maximum transverse shift of the horizontal polarization state with 11.5 μm is obtained when the thickness of Si film is optimum. There is at least an order of magnitude enhancement in contrast with the transverse shift in the conventional SPR configuration. Our research is important for providing an effective way to improve the photonic SHE and may offer the opportunity to characterize the parameters of the dielectric layer with the help of weak measurements and development of sensors based on the photonic SHE.

Surface-wave-based optical sensing of an analyte in a fluid relies on the sensitivity of the surface wave to the electromagnetic properties of the analyte-containing fluid in the vicinity of the guiding interface. Surfaceplasmon-polariton (SPP) waves are most commonly used for optical sensing because of the ease of the excitation of an SPP wave when the fluid is partnered with a metal. If the fluid is replaced by a porous, anisotropic, and periodically nonhomogeneous solid filled with the fluid, while the metal is replaced by an isotropic homogeneous dielectric material, the surface wave is called a Dyakonov–Tamm (DT) wave. We have theoretically determined that the incorporation of the DT-waveguiding interface in a prism-coupled configuration provides an alternative to the analogous SPP wave-based sensor, with comparable dynamic sensitivity.