The University of Southampton
University of Southampton Institutional Repository

Design and fabrication of indium phosphide air-bridge waveguides with MEMS functionality

Design and fabrication of indium phosphide air-bridge waveguides with MEMS functionality
Design and fabrication of indium phosphide air-bridge waveguides with MEMS functionality
We present the design and fabrication of a dual air-bridge waveguide structure integrated with MEMS functionality. The structure is designed to function as a tunable optical buffer for telecommunication application. The optical buffer structure is based on two parallel waveguides made of high refractive index material with subwavelength dimensions. They are suspended in air, and are separated by a sub-micron air gap. Due to the fact that the size of the waveguides is much smaller than the wavelength of light that propagates in the structure, a significant fraction of the optical mode is in the air gap between the waveguides. By changing the size of the air gap using MEMS techniques, we can vary this fraction and hence the effective refractive index of the waveguide structure, thus generating tunable optical delay.

The optical buffer structure was grown on an InP substrate by molecular beam epitaxy, and the device layer was made of InGaP. An InGaAs layer was sandwiched between the device layer and the substrate to serve as a sacrificial layer. The sub-micron waveguides, their supports in the form of side pillars with tapered shapes in order to minimize optical losses, and the MEMS structures were patterned using electron beam lithography and plasma etching. Electrodes were integrated into the structure to provide electrostatic actuation. After the sample patterning, the waveguide structure was released using HF etch. Our simulations predict that by varying the waveguide separation from 50 nm to 500 nm, we could achieve a change in propagation delay by a factor of two.
optical buffer, waveguide, III-V semiconductors, MEMS, MOEMS, optical delay, actuation
Ng, W.H.
8d085a91-7054-4571-986b-4d6723f901ea
Podoliak, Nina
0908b951-00a7-48a5-bc82-631640910b9c
Horak, P.
520489b5-ccc7-4d29-bb30-c1e36436ea03
Wu, J.
5a0119e5-a760-4ff5-90b9-ec69926ce501
Liu, H.
2f4354df-09da-483b-90ef-1182d7275095
Stewart, W.J.
bbe93aab-9477-4f08-9042-a0c453aeb7a5
Kenyon, A.J.
e2e3bbbc-23b6-4c67-832d-9a16abf4aa31
Ng, W.H.
8d085a91-7054-4571-986b-4d6723f901ea
Podoliak, Nina
0908b951-00a7-48a5-bc82-631640910b9c
Horak, P.
520489b5-ccc7-4d29-bb30-c1e36436ea03
Wu, J.
5a0119e5-a760-4ff5-90b9-ec69926ce501
Liu, H.
2f4354df-09da-483b-90ef-1182d7275095
Stewart, W.J.
bbe93aab-9477-4f08-9042-a0c453aeb7a5
Kenyon, A.J.
e2e3bbbc-23b6-4c67-832d-9a16abf4aa31

Ng, W.H., Podoliak, Nina, Horak, P., Wu, J., Liu, H., Stewart, W.J. and Kenyon, A.J. (2015) Design and fabrication of indium phosphide air-bridge waveguides with MEMS functionality. SPIE Microtechnologies conference, Spain. 04 - 06 May 2015. 6 pp .

Record type: Conference or Workshop Item (Paper)

Abstract

We present the design and fabrication of a dual air-bridge waveguide structure integrated with MEMS functionality. The structure is designed to function as a tunable optical buffer for telecommunication application. The optical buffer structure is based on two parallel waveguides made of high refractive index material with subwavelength dimensions. They are suspended in air, and are separated by a sub-micron air gap. Due to the fact that the size of the waveguides is much smaller than the wavelength of light that propagates in the structure, a significant fraction of the optical mode is in the air gap between the waveguides. By changing the size of the air gap using MEMS techniques, we can vary this fraction and hence the effective refractive index of the waveguide structure, thus generating tunable optical delay.

The optical buffer structure was grown on an InP substrate by molecular beam epitaxy, and the device layer was made of InGaP. An InGaAs layer was sandwiched between the device layer and the substrate to serve as a sacrificial layer. The sub-micron waveguides, their supports in the form of side pillars with tapered shapes in order to minimize optical losses, and the MEMS structures were patterned using electron beam lithography and plasma etching. Electrodes were integrated into the structure to provide electrostatic actuation. After the sample patterning, the waveguide structure was released using HF etch. Our simulations predict that by varying the waveguide separation from 50 nm to 500 nm, we could achieve a change in propagation delay by a factor of two.

Text
6905.pdf - Other
Download (611kB)

More information

Published date: May 2015
Venue - Dates: SPIE Microtechnologies conference, Spain, 2015-05-04 - 2015-05-06
Keywords: optical buffer, waveguide, III-V semiconductors, MEMS, MOEMS, optical delay, actuation
Organisations: Optoelectronics Research Centre, Quantum, Light & Matter Group

Identifiers

Local EPrints ID: 384460
URI: https://eprints.soton.ac.uk/id/eprint/384460
PURE UUID: f3faa83b-d74d-4fe8-be19-cbc68d5fc190
ORCID for Nina Podoliak: ORCID iD orcid.org/0000-0002-3146-0355
ORCID for P. Horak: ORCID iD orcid.org/0000-0002-8710-8764

Catalogue record

Date deposited: 02 Dec 2015 10:10
Last modified: 18 Jul 2019 01:00

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×