The University of Southampton
University of Southampton Institutional Repository

Germanium vertically light-emitting micro-gears generating orbital angular momentum

Germanium vertically light-emitting micro-gears generating orbital angular momentum
Germanium vertically light-emitting micro-gears generating orbital angular momentum
Germanium (Ge) is capturing researchers'interest as a possible optical gain medium implementable on Complementary Metal-Oxide-Semiconductor (CMOS) chips. Band-gap engineering techniques, relying mainly on tensile strain, are required to overcome the indirect band-gap nature of bulk Ge and promote electrons injection into the direct-gap valleys. We used Ge-on-SOI wafers with a high-crystalline-quality Ge layer to fabricate Ge micro-gears on Silicon (Si) pillars. Micro-gears are created by etching a periodic grating-like pattern on the circumference of a conventional micro-disk, resulting in a gear shape. Thermal built-in stresses within the SiO2 layers that encapsulate the micro-gears were used to impose tensile strain on Ge. Biaxial tensile strain values ranging from 0.3-0.5% are estimated based on Raman spectroscopy measurements and Finite-Element Method (FEM) simulations. Multiple sharp-peak resonances within the Ge direct-gap were detected at room temperature by Photo-Luminescence (PL) measurements. Investigating the micro-gears spectrum using Finite-Difference Time-Domain (FDTD) simulations, we identified vertically emitted optical modes with non-zero Orbital Angular Momentum (OAM).
1094-4087
34675-34688
Al-Attili, Abderlrahman Z.
37ee3caf-698f-4311-8020-cb9f4485def3
Burt, Daniel
49c801a2-fb48-40f2-b72f-f713151b96e6
Li, Zuo
05f14f5e-fc6e-446e-ac52-64be640b5e42
Higashitarumizu, Naoki
0a322ee5-f9f7-45d0-82d3-c3194caa4f52
Gardes, Frederic
7a49fc6d-dade-4099-b016-c60737cb5bb2
Oda, Katsuya
7a476aa6-20a1-4d0a-938f-99d52720ae68
Ishikawa, Yasuhiko
e969492d-8143-4aca-9f9c-af4de65b7377
Saito, Shinichi
14a5d20b-055e-4f48-9dda-267e88bd3fdc
Al-Attili, Abderlrahman Z.
37ee3caf-698f-4311-8020-cb9f4485def3
Burt, Daniel
49c801a2-fb48-40f2-b72f-f713151b96e6
Li, Zuo
05f14f5e-fc6e-446e-ac52-64be640b5e42
Higashitarumizu, Naoki
0a322ee5-f9f7-45d0-82d3-c3194caa4f52
Gardes, Frederic
7a49fc6d-dade-4099-b016-c60737cb5bb2
Oda, Katsuya
7a476aa6-20a1-4d0a-938f-99d52720ae68
Ishikawa, Yasuhiko
e969492d-8143-4aca-9f9c-af4de65b7377
Saito, Shinichi
14a5d20b-055e-4f48-9dda-267e88bd3fdc

Al-Attili, Abderlrahman Z., Burt, Daniel, Li, Zuo, Higashitarumizu, Naoki, Gardes, Frederic, Oda, Katsuya, Ishikawa, Yasuhiko and Saito, Shinichi (2018) Germanium vertically light-emitting micro-gears generating orbital angular momentum. Optics Express, 26 (26), 34675-34688. (doi:10.1364/OE.26.034675).

Record type: Article

Abstract

Germanium (Ge) is capturing researchers'interest as a possible optical gain medium implementable on Complementary Metal-Oxide-Semiconductor (CMOS) chips. Band-gap engineering techniques, relying mainly on tensile strain, are required to overcome the indirect band-gap nature of bulk Ge and promote electrons injection into the direct-gap valleys. We used Ge-on-SOI wafers with a high-crystalline-quality Ge layer to fabricate Ge micro-gears on Silicon (Si) pillars. Micro-gears are created by etching a periodic grating-like pattern on the circumference of a conventional micro-disk, resulting in a gear shape. Thermal built-in stresses within the SiO2 layers that encapsulate the micro-gears were used to impose tensile strain on Ge. Biaxial tensile strain values ranging from 0.3-0.5% are estimated based on Raman spectroscopy measurements and Finite-Element Method (FEM) simulations. Multiple sharp-peak resonances within the Ge direct-gap were detected at room temperature by Photo-Luminescence (PL) measurements. Investigating the micro-gears spectrum using Finite-Difference Time-Domain (FDTD) simulations, we identified vertically emitted optical modes with non-zero Orbital Angular Momentum (OAM).

Text
A.Attili-OE-v3 - Accepted Manuscript
Available under License Other.
Download (4MB)

More information

Accepted/In Press date: 20 November 2018
e-pub ahead of print date: 21 December 2018
Additional Information: © 2018 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved

Identifiers

Local EPrints ID: 426480
URI: https://eprints.soton.ac.uk/id/eprint/426480
ISSN: 1094-4087
PURE UUID: c7203239-6903-40af-bd18-88ab8a778816
ORCID for Shinichi Saito: ORCID iD orcid.org/0000-0003-1539-1182

Catalogue record

Date deposited: 28 Nov 2018 17:30
Last modified: 14 Mar 2019 05:02

Export record

Altmetrics

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.

×