A new proposal towards the polarization tunable Goos-Hänchen (GH) and Imbert-Fedorov (IF) spatial and angular shifts is explored analytically in a four layer Kretschmann-Raether geometry comprising a ZnSe prism, a dielectric layer of PMMA-DR1 (Polymethylmthacryalate-Disperse red) and two metal layers of silver having thicknesses of 50 nm and 200 nm respectively. Observations from the different graphical representations reveal that in correspondence of the long range surface plasmon (LRSP) resonant angle both spatial and angular GH shifts get appreciably enhanced in case of p polarized light whereas negligible or very less amplification of spatial and angular GH shifts are obtained for s polarized light. With the switching of polarization of the incident light beam on the proposed configuration through the half wave plate, the spatial and angular GH shift is tuned from -17.35 μm to 0.105 μm and -0.631 μrad to 4.28 nrad respectively and the spatial and angular IF shift is tuned from 94.16 μm to -53.58 μm and about 7.774 μrad to -11.17 μrad respectively. To the best of our knowledge, several articles have been devoted for depicting the GH shift without considering the IF shift, whereas the exact beam position of the output beam can only be identified with the composite effect of GH and IF spatial and angular shifts. The above new proposal can be implemented in the field of fine tuning of optical switching at the μm ranges with varying polarization, optical sensors applications and serves interesting opportunities to make atomic mirrors.
This paper analytically describes the surface plasmon enhanced very low threshold second harmonic generation formed by a 29 nm thin gold layer is sandwiched between a BK<sub>7</sub> prism plane and 20 nm thin GaAs layer. Here the electric field with incident optical radiation of picowatt level is amplified upto milliwatt level through surface plasmon phenomenon at off resonance condition. This amplified output further coupled to a whispering gallery resonator, which facilitates the generation of second harmonic for an incident optical radiation of picowatt level. In this proposed configuration with an incident optical power of 94.6 pW generated second harmonic through whispering gallery resonator found to be 14.6 mW.