# Nanophotonic modal dichroism: mode-multiplexed modulators

## TL;DR

This paper introduces a novel nanophotonic modulator that uses mode-selective absorption in a waveguide to independently modulate multiple modes, significantly increasing device functionality within a compact footprint.

## Contribution

It proposes a new mode-multiplexed nanophotonic modulator design based on mode-selective absorption in patterned ITO, enabling independent control of multiple modes at telecom wavelengths.

## Key findings

- Two modes can be independently modulated.
- Device performance comparable to conventional single-mode ITO modulators.
- Design principles enable increased functionality-per-area in integrated photonics.

## Abstract

As the diffraction limit is approached, device miniaturization to integrate more functionality per area becomes more and more challenging. Here we propose a novel strategy to increase the functionality-per-area by exploiting the modal properties of a waveguide system. With such approach the design of a mode-multiplexed nanophotonic modulator relying on the mode-selective absorption of a patterned Indium-Tin-Oxide is proposed. Full-wave simulations of a device operating at the telecom wavelength of 1550nm show that two modes can be independently modulated, while maintaining performances in line with conventional single-mode ITO modulators reported in the recent literature. The proposed design principles can pave the way to a novel class of mode-multiplexed compact photonic devices able to effectively multiply the functionality-per-area in integrated photonic systems.

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Source: https://tomesphere.com/paper/1705.07954