Bibliographic Details
| Title: |
Toward Higher Integration Density in Femtosecond-Laser-Written Programmable Photonic Circuits |
| Authors: |
Riccardo Albiero, Ciro Pentangelo, Marco Gardina, Simone Atzeni, Francesco Ceccarelli, Roberto Osellame |
| Source: |
Micromachines, Vol 13, Iss 7, p 1145 (2022) |
| Publisher Information: |
MDPI AG, 2022. |
| Publication Year: |
2022 |
| Collection: |
LCC:Mechanical engineering and machinery |
| Subject Terms: |
femtosecond laser micromachining, programmable photonic circuits, thermal phase shifting, universal photonic processors, Mechanical engineering and machinery, TJ1-1570 |
| More Details: |
Programmability in femtosecond-laser-written integrated circuits is commonly achieved with the implementation of thermal phase shifters. Recent work has shown how such phase shifters display significantly reduced power dissipation and thermal crosstalk with the implementation of thermal isolation structures. However, the aforementioned phase shifter technology is based on a single gold film, which poses severe limitations on integration density and circuit complexity due to intrinsic geometrical constraints. To increase the compactness, we propose two improvements to this technology. Firstly, we fabricated thermal phase shifters with a photolithography process based on two different metal films, namely (1) chromium for microheaters and (2) copper for contact pads and interconnections. Secondly, we developed a novel curved isolation trench design that, along with a state-of-the-art curvature radius, allows for a significant reduction in the optical length of integrated circuits. As a result, curved Cr-Cu phase shifters provide a compact footprint with low parasitic series resistance and no significant increase in power dissipation (∼38 mW) and thermal crosstalk (∼20%). These results pave the way toward the fabrication of femtosecond-laser-written photonic circuits with a steep increase in terms of layout complexity. |
| Document Type: |
article |
| File Description: |
electronic resource |
| Language: |
English |
| ISSN: |
2072-666X |
| Relation: |
https://www.mdpi.com/2072-666X/13/7/1145; https://doaj.org/toc/2072-666X |
| DOI: |
10.3390/mi13071145 |
| Access URL: |
https://doaj.org/article/ef6062537a8b460696032136d7794a81 |
| Accession Number: |
edsdoj.f6062537a8b460696032136d7794a81 |
| Database: |
Directory of Open Access Journals |
