Analytical theory of optical bistability in plasmonic nanoresonators

Abstract

We present approximate analytical expressions describing the optical bistability phenomenon in a plasmonic-gapwaveguide-based nonlinear device. The device is formed by a metal-dielectric-metal (MDM) waveguide perpendicularly coupled to a stub structure that is filled with an optically nonlinear medium. Among the recently reported studies on nonlinearity-induced bistability in plasmonic nanostructures, our work stands out because of its pure analytic approach and the considered device geometry. The scattered-field technique that we employ here is hinged on the concepts of circuit theory and the characteristic-impedance model for single-mode MDM waveguides. By properly accounting for surface-plasmon damping, multiple reflections, and the Kerr effect, we obtain a fairly accurate parametric relation connecting the input and output intensities of the device. The impact of changing the operating wavelength and geometrical parameters of the stub on the bistable switching thresholds and the hysteresis loop width is demonstrated using a number of numerical examples. The derived relation is useful for rapid design optimization of plasmonic switches and memories.

Optical switching and bistability in T-shaped nanoplasmonic waveguide

“…Optical bistability is analyzed by relating the input and output intensities, I in and I out respectively of the waveguide coupled nanostub structure and can be expressed as [11]:…”

“…Pannipitiya, et. al. recently formulated a mathematical model using scattering matrix theory and microwave transmission line analogy to analyze optical bistability using nonlinear material in a nanostub, coupled to plasmonic waveguide [11]. Though optical switching in nanostub-waveguide coupled systems have been achieved using absorbing active substance [12], but detailed study of optical switching using nonlinear material in plasmonic nanostub systems have somehow remained untouched.…”

“…Hence, detailed investigation of optical switching using Kerr medium in the nanostub, which had not been explored earlier to the best of our knowledge has been the matter of study in our present work. Moreover, the analytical formulation in [11] has motivated and facilitated the study of optical bistability in our nonlinear plasmonic switch.…”

Optical multiple bistability in metal-insulator-metal plasmonic waveguides side-coupled with twin racetrack resonators

“…To overcome this drawback, a MIM waveguide coupled to a resonator has been proposed recently. To realize the optical bistability, switchable systems constructed by embedding a nonlinear material in an MIM plasmonic waveguide have been reported recently [22][23][24][25][26][27][28][29].…”

Analytical theory for the nonlinear optical response of a Kerr-type standing-wave cavity side-coupling to a MIM waveguide

“…The performances of various SPP devices based on the Kerr nonlinearity have been investigated theoretically [13][14][15] and experimentally [16,17]. Optical bistability, which is an important third-order optical nonlinear effect, has also been observed in different SPP waveguide-cavity structures [18,19], and even used for the design of all-optical bistable SPP switches [20,21]. However, almost all investigations of the optical bistability in SPP waveguide-cavity structure so far are based on numerical simulation methods, mainly the finite-difference time-domain (FDTD) technique, which makes it difficult to get insight to the fundamental physical mechanism of such an optical bistability phenomenon.…”