2018 Session – Technologies from visible to mid-infrared applications

Synchronization of Modelocked Coupled Microresonator Combs

Jae K. Jang, Alexander Klenner, Xingchen Ji, Yoshitomo Okawachi, Michal Lipson, and Alexander L. Gaeta
Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
School of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853, USA
Department of Electrical Engineering, Columbia University, New York, NY 10027, USA *Tel: +1-212-854-6564, e-mail: a.gaeta@columbia.edu

We report the first experimental synchronization of two modelocked chip-based frequency combs. The synchronization is established passively via an optical fiber link for lengths up to 20 m and allows for coherent combining of the generated soliton pulses. Such a system could have applications in data communications, imaging, and clock distribution.

Keywords: microresonator combs, nonlinear photonics, synchronization, four-wave mixing

141 Th.2.B.1 141-Regular Paper, Synchronization of Modelocked Coupled Microresonator Combs

Low-loss inverted taper edge coupler in silicon nitride

Juan Fernández, Rocío Baños, David Doménech, Carlos Domínguez and Pascual Muñoz
VLC Photonics S.L, c/ Camino de Vera s/n – 46022, Valencia – Spain – david.domenech@vlcphotonics.com
Universitat Politènica de València, c/ Camino de Vera s/n
46022, Valencia – Spain – pascual.munoz@upv.es
Instituto de Microelectrónica de Barcelona (IMB-CNM), CSIC
Bellaterra 08193 – Spain

An inverted lateral taper with one vertical discrete step was designed for a medium confinement silicon nitride waveguide platform in the C-band, as chip edge coupler, with predicted insertion loss of 0.58 dB. The design is supported by an extensive study to evaluate the impact of fabrication process variations in the performance of such coupler. The device was manufactured and measured, showing an insertion loss of 1.47 dB, which was traced back to fabrication process variations as cross-checked with simulations. To our knowledge, the reported edge coupler is the shortest and among the best performing found for silicon nitride platforms.

Keywords: Silicon nitride, photonic integrated circuits, fiber coupling, inverted taper

Th.2.B.2 110-Regular Paper, Low-loss inverted taper edge coupler in silicon nitride

Mid-infrared Suspended Waveguide Platform and Building Blocks

J. G. Wangüemert-Pérez, A. Sánchez-Postigo, J. Soler Penades, A. Ortega-Moñux, M. Nedeljkovic, R. Halir, F. El Mokhtari Mimun, Y.X. Cheng, Z. Qu, A.Z. Khokhar, A. Osman, W. Cao, C.G. Littlejohns, P. Cheben, G. Z. Mashanovich, I. Molina-Fernández
Universidad de Málaga, Dpto. Ingeniería de Comunicaciones, ETSI-Telecomunicación, 29071 Málaga, Spain
Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, United Kingdom
National Research Council Canada, Building M-50, Ottawa, K1A 0R6 Canada *Corresponding author: gonzalo@ic.uma.es

In this work we present our recent progress in the development of a platform for the mid-infrared wavelength range, based on suspended silicon waveguide with subwavelength metamaterial cladding. The platform has some intrinsic advantages, which make it a very promising candidate for sensing applications in the fingerprint region. Specifically, it can cover the full transparency window of silicon (up to a wavelength of 8 µm), only requires one lithographic etch-step and can be designed for strong light-matter interaction. Design rules, practical aspects of the fabrication process and experimental results of a complete set of elemental building blocks operating at two very different wavelengths, 3.8 µm and 7.67 µm, will be discussed. Propagation losses as low as 0.82 dB/cm at λo=3.8 µm and 3.1 dB/cm at λo=7.67 µm are attained, for the interconnecting waveguides.

Keywords: Integrated optics, Subwavelength structures, Mid-infrared, Waveguides, Optical devices.

Th.2.B.3 24-Invited Paper, Gonzalo Wangüemert (Univ. Málaga), “Mid-infrared suspended waveguide platform & building blocks”

A new platform for integrated quantum optics: the short-wave infrared

Lawrence Rosenfeld, Joshua W. Silverstone, Benjamin Slater, Döndü Sahin, Alex McMillan, Mark G. Thompson
Quantum Engineering Technology Labs, H. H. Wills Physics Laboratory and Department of Electrical and Electronic Engineering, University of Bristol, Bristol BS8 1FD, UK
Quantum Engineering Centre for Doctoral Training, H. H. Wills Physics Laboratory and Department of Electrical and Electronic Engineering, University of Bristol, Bristol BS8 1FD, UK
e-mail: josh.silverstone@bristol.ac.uk

Integrated silicon photonic circuits are a promising candidate for large scale quantum optics experiments. Parasitic nonlinear absorption at near-IR (NIR) can be reduced or entirely eliminated by translating to the shortwave infrared (SWIR) band ca. 2.1 µm. We measure superconducting nanowire single photon detector efficiency, low loss multi-mode waveguides with 0.21 dB/cm attenuation and nonlinear absorption induced by a picosecond pulsed laser to be α2 = 0.475 ×10-12 m/W – an order of magnitude less than in NIR single-mode waveguides. This work demonstrates the feasibility for large scale integrated quantum photonics.

Keywords: Integrated photonics, mid-infrared optics, quantum optics, nonlinear optics

Th.2.B.4 94-Regular Paper, A new platform for integrated quantum optics the short-wave infrared

High-efficiency SiN Grating Fiber-Chip Coupler with Bottom Reflector

Siddharth Nambiar, Abhai Kumar., Rakshitha K., Praveen Ranganath, Shankar Kumar Selvaraja Center for Nanoscience and Engineering, Indian Institute of Science, Bengaluru -560012
Tel: : +91 80 2293 3342 , e-mail: shankar.ks@iisc.ac.in

We design and experimentally demonstrate a high efficiency SiN grating coupler on a 500 nm thick platform with distributed Bragg layers as bottom reflectors. Maximum efficiency for the design is calculated to be over 73 % with a 1 dB bandwidth of 56 nm. The experimental peak coupling efficiency is observed to be 2.29 dB/coupler with a 1 dB bandwidth of 49 nm.

Keywords: Grating coupler, photonic-integrated circuits, silicon nitride.

Th.2.B.5 59-Regular Paper, High-efficiency SiN Grating Fiber-Chip Coupler with Bottom Reflector

PIX4life: photonic integrated circuits for bio-photonics

Marco A. G. Porcel, J. David Domenech, Hilde Jans, Romano Hoofman, Douwe Geuzebroek, Pieter Dumon, Marcel van der Vliet, Jeremy Witzens, Eric Bourguignon, Iñigo Artundo and Liesbet Lagae
VLC Photonics S.L., c/ Camino de Vera s/n – 46021 Valencia – Spain
Tel: +34961337884, e-mail: marco.garcia@vlcphotonics.com
IMEC, Kapeldreef 75, 3001 Heverlee, Belgium
LioniX Int., Hengelosestraat 500 – Enschede – The Netherlands
Luceda Photonics, – Noordlaan 21 – Belgium
PhoeniX BV, – Capitool 50, 7521 – Enschede – The Netherlands
RWTH Aachen University, Aachen – Germany
Toptica, – Lochhamer Schlag 19 – 82166 – Grafelfing – Germany

As key enabling technology, photonics has become critical in many fields. Advances in fabrication technologies have realized photonic integrated circuits not only for telecommunication wavelengths but also in the mid-infrared, and very importantly, in the visible. The latter can strongly benefit bio- and life-science applications where visible light is very commonly used in bulky and expensive optical systems. Through PICs Robust optical functionalities can be realized cost-effectively. However, the technology was not openly available until very recently. The pilot line, PIX4life, was established with the aid of the European Union to facilitate European R&D employing visible light PICs for visible applications, targeting mainly health and bio-science applications.

Keywords: Pilot line, PIX4life, silicon nitride photonics, biophotonics, life sciences, visible wavelength, short near-infrared

Th.2.B.6 25-Invited Paper, David Domenech-VLC, “PIX4life developments the path towards a visible light photonic foundry”