Optical hysteresis in SPR structures with amorphous As₂S₃film under low-power laser irradiation

Abstract

Optical hysteresis is a fundamental phenomenon that can lead to optical bistability and highspeed signal processing. Here, we present a theoretical and experimental study of the optical hysteresis phenomenon in amorphous As 2 S 3 chalcogenide based waveguide structures under surface plasmon resonance (SPR) conditions. The SPR structure is irradiated with low power CW Ar laser radiation at 514 nm wavelength, with photon energy near the optical band-gap of As 2 S 3 , in a Kretschmann-Raether configuration. First, we determined the incidence angle on the SPR structure for resonant coupling of the laser radiation within the waveguide structure. Subsequently, by setting the near resonance incidence angle, we analyzed the variation of the laser power reflected on the SPR structure with incident power. We demonstrated that, by setting the incidence angle at a value slightly smaller than the resonance angle, the increase followed by the decrease of the incident power lead to a wide (up to 60%) hysteresis loop of the reflected power. This behavior is related to the slow and persistent photo-induced modification of the complex refractive index of As 2 S 3 under 514 nm laser irradiation. The experimental and theoretical results are in good agreement, demonstrating the validity of the theoretical model presented here.

Four-Layer Surface Plasmon Resonance Structures with Amorphous As2S3 Chalcogenide Films: A Review

“…Such small modifications raise serious challenges in terms of reproducibility and technology for producing and storing the thin layers. More sensitive experimental methods have to be used for characterizations, as in [ 57 ], which presents a study on reversible photo-induced phenomena that occur within amorphous ChG material put in a structure that supports SPR resonance.…”

Chalcogenide Science in Romania

“…Investigations regarding application of amorphous chalcogenide in plasmonic resonance configuration were presented in a published article. [ 55 ]…”