Gain-induced switching in metal-dielectric-metal plasmonic waveguides

Abstract

The authors show that the incorporation of gain media in only a selected device area can annul the effect of material loss, and enhance the performance of loss-limited plasmonic devices. In addition, they demonstrate that optical gain provides a mechanism for on/off switching in metal-dielectric-metal (MDM) plasmonic waveguides. The proposed gain-assisted plasmonic switch consists of a subwavelength MDM plasmonic waveguide side-coupled to a cavity filled with semiconductor material. In the absence of optical gain in the semiconductor material filling the cavity, an incident optical wave in the plasmonic waveguide remains essentially undisturbed by the presence of the cavity. Thus, there is almost complete transmission of the incident optical wave through the plasmonic waveguide. In contrast, in the presence of optical gain in the semiconductor material filling the cavity, the incident optical wave is completely reflected. They show that the principle of operation of such gain-assisted plasmonic devices can be explained using a temporal coupled-mode theory. They also show that the required gain coefficients are within the limits of currently available semiconductor-based optical gain media.

Plasmonic modulator based on gain-assisted metal–semiconductor–metal waveguide

“…Another possibility to control propagation of light in a MIM waveguide by changing permittivity of the medium in side-coupled cavities was theoretically analyzed in [28,[30][31][32]. In particular, it was shown that implementation of gain media in parts of the waveguide can compensate losses along the device [30].…”

Integrated liquid crystal optical switch based on double teeth-shaped structure at telecom wavelengths

“…Several different metal-insulator-metal (MIM) waveguide structures based on SPPs have been numerically and/or experimentally demonstrated, such as U-shaped waveguides [5], splitters [6], Y-shaped combiners [7], multimode interferometers [8], couplers [9,10] and Mach-Zehnder interferometers [11,12]. Optical switches based on different physical mechanisms with different structures have been proposed [13][14][15][16]. Also, different physical mechanisms can be used to control the refractive index, such as the electrooptical effect [13], the plasma dispersion effect [17] and the thermo-optic effect [18].…”

An ultra-compact nanoplasmonic high-pass wavelength filter at telecommunication wavelengths based on a MIM waveguide

“…Miscellaneous structures based on MIM (Metal-Insulator-Metal) plasmonic waveguide such as ring resonator [2] and switch [3] have been suggested. Optical filters, selectively transmit light in a specific range of interest, while blocking others are important parts of modern communication systems with broad range of applications such as Wavelength division multiplexing (WDM) and gain equalization.…”