# Low-loss Waveguide Fabrication by Inkjet Printing on Porous Silicon

## TL;DR

This paper introduces a mask-less, inkjet printing method to fabricate low-loss optical waveguides within porous silicon, allowing precise 2D refractive index control and demonstrating effective light guiding at telecom wavelengths.

## Contribution

It presents a novel inkjet printing technique for creating embedded optical waveguides in porous silicon with tunable optical properties, enabling low-loss light transmission.

## Key findings

- Achieved light guiding at 1.064 and 1.550 microns.
- Measured attenuation of 2.5 dB/cm and below 1.3 dB/cm.
- Demonstrated full 2D refractive index control.

## Abstract

We report fabrication of optical waveguides embedded in oxidised porous silicon in a mask-less process. Patterned pore-filling was attained by means of inkjet printing, enabling lateral modification of the waveguide's index of refraction and other optical properties thus providing full two-dimensional refractive index control of the optical waveguide. The waveguides were created by applying a KDP salt solution over a porous silicon film by means of a material printer. Light guiding was demonstrated at wavelengths 1.064 and 1.550 microns. Measured values of the intensity attenuation at these wavelengths were 2.5 dB/cm and below 1.3 dB/cm respectively

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Source: https://tomesphere.com/paper/1812.03881