Design and optimization of a waveguide/fibre coupler in the visible range

Paulo Lourenço; Alessandro Fantoni; João Costa; Miguel Fernandes; Manuela Vieira

doi:10.1117/12.2582938

5 March 2021 Design and optimization of a waveguide/fibre coupler in the visible range

Paulo Lourenço, Alessandro Fantoni, João Costa, Miguel Fernandes, Manuela Vieira

Proceedings Volume 11680, Physics and Simulation of Optoelectronic Devices XXIX; 1168019 (2021) https://doi.org/10.1117/12.2582938
Event: SPIE OPTO, 2021, Online Only

Abstract

When engineering photonic integrated structures, there will be a time that one must consider coupling out the electromagnetic field to an external device. Often, this coupling is made through a single mode optical fibre. Due to the mismatch in mode field diameters between waveguide and fibre modes, the propagating mode inside the dielectric waveguide must undertake a spot-size conversion. It requires to be radially expanded, often laterally by a tapered waveguide and longitudinally through other means, to match the radial profile of the optical fibre mode. Then, the energy must be coupled out of its propagating path into the plane of the optical fibre, through a structure that possesses such functional purpose. In this work, we describe the design steps and optimization of a silicon nitride waveguide/fibre coupler operating in the visible range. To this end, we start by designing an optimized 3D taper waveguide, using Beam Propagation method, that performs as the spot-size converter. Next, through the Eigen Mode Expansion method, a 2D subwavelength grating is designed and optimized regarding substrate leakage and propagating plane energy coupling out, thus vertically validating the energy distribution of the outgoing profile. The required subwavelength grating apodization is accomplished, once more through the Eigen Mode Expansion method, and by carefully engineering a metamaterial that performs accordingly. The obtained diffraction grating is then expanded horizontally to create a 3D structure and laterally validated through Beam Propagation method. Finally, the whole 3D structure is optimized and validated through Finite Differences Time Domain simulations regarding energy profile coupling out, and overlap integral matching is established with the fibre mode profile.

Conference Presentation

Citation Download Citation

Paulo Lourenço, Alessandro Fantoni, João Costa, Miguel Fernandes, and Manuela Vieira "Design and optimization of a waveguide/fibre coupler in the visible range", Proc. SPIE 11680, Physics and Simulation of Optoelectronic Devices XXIX, 1168019 (5 March 2021); https://doi.org/10.1117/12.2582938

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available