Session 10 | Simulations / Modelling

Analysis of Quantum Dot Single Section FP Lasers for Comb Spectra Generation

1Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Torino, Italy

There is an increasing interest on Quantum Dot lasers as light source in silicon photonic integrated circuit; one promising application is the use of a QD comb laser as compact WDM source that could replace a DFB array more difficult to integrate with the Si PIC[1]. Many experiments on single section Fabry Perot QD lasers have demonstrated the possibility of generating wide optical comb spectra at telecom wavelengths but there is still a lack of modelling work for providing physical explanations on the capability of the QD lasers of generating phase locked optical modes. We present a Time Domain Travelling Wave model we have recently developed to move the first step in this direction [2]. We discuss here the role of some key QD material parameters such as the large gain compression factor (ε-parameter), the inhomogeneous gain broadening due to QD self-assembled growth process, the homogeneous gain broadening due to polarization dephasing time and the carrier relaxation time.


Rate-Equation Analysis for an Integrated Coupled- Cavity Laser with MMI Anti-Phase Coupler

Daan LENSTRA Eindhoven University of Technology, P.O.Box 513, 5600MB , The Netherlands

In this paper a dynamical theory is reported for the coupled-cavity laser (CCL) with a multi-mode interference (MMI) coupler, which provides an excellent description of the locking and other operational aspects of the laser realized by D’Agostino et al. in 2015 [1]. The revived interest in CCLs as widely tuneable lasers for sensing and other applications is due to the specially designed MMI anti-phase coupler as described in [1]. The theory explains if, why and how the two individual isolated constituent modes combine to one single “super mode”, a situation referred to as locked state. A comprehensive formulation of the model and derivation of the rate equations for the CCL with quantum-well active material can be found in [2].


Angled 3D Glass-to-SiPh adiabatic coupler

1National Technical University of Athens, Patission 42, Athens, 10682, reece
2Optoscribe Ltd, 5 Bain Square, Kirkton Campus, Livingston, EH54 7DQ. UK
3TE Connectivity, Rietveldenweg 32, 5222 AR ‘s-Hertogenbosch, The Netherlands

Concept Despite the promise of Silicon Photonics (SiPh) towards next-generation deployments seamlessly combining the on-chip advanced optical functionality with efficient E/O and O/E conversion, their wide penetration across all communication layers is currently hindered by the lack of efficient and scalable optical input-outputs (I/O) that can be realized using standard low-cost assembly equipment. To this end, diffraction-based structures, such as grating couplers, have been lately superseded by in-place coupling solutions employing inverse tapers [1] or metamaterial waveguides [2] in order to achieve coupling to SMFs through spot-size conversion. Nevertheless, those structures suffer from either increased fabrication complexity, including material engineering and undercut waveguide sections, or considerable losses due to poor mode matching. Recently, a very interesting concept was presented by Soganci et al. [3], proposing a compliant polymer interface between SMFs and nanophotonic waveguides, relying on adiabatic coupling. The first experimental demonstration of the interface [4] revealed the necessity of a well-defined, angled adhesive gap so as contain the scattering loss at the chip edge that is degrading the performance. However, considering the coefficient of thermal expansion (CTE) mismatch between the polymer and the SiPh chip, such an accurate control over the adhesive gap will significantly increase the intricacy of the assembly process.


Optimization of Silicon Photonic Components using Multi-Fidelity Simulations and Co-Kriging

Pierre WAHL16, Ivo COUCKUYT2, Christian KREMERS3, Frank DEMMING3 Tom DHAENE2, Wim BOGAERTS145*
1 Luceda Photonics, Dendermonde, Belgium
2 Surrogate Modelling Group, Ghent University-iMinds, Dept. of Information Technology, G. Crommenlaan 8 Blok C0 bus 201, 9050 Ghent, Belgium
3 CST-Computer Simulation Technology AG, Bad Nauheimer Strasse 19, 64289 Darmstadt, Germany.
4 Photonics Research Group, Ghent University-Imec, Technologiepark 15, 9052 Ghent, Belgium
5 Center for Nano- and Biophotonics, Ghent University, Belgium
6 Brussels Photonics Team B-PHOT, Department of Applied Physics and Photonics, Vrije Universiteit Brussel, Brussels, Belgium

Silicon photonic devices can be very compact because of the high refractive index contrast. But this also makes them very sensitive to geometry variations, and hard to model [1]. Typically, a fully vectorial, 3D solution of Maxwell’s equations is the only reliable simulation technique, be it with eigenmode expansion (EME) or finite-difference-time-domain (FDTD). Finding an optimum geometry of a parametric component is therefore computationally very expensive, and it is important to keep the number of these ‘expensive’ simulation as small as possible. Efficient global optimization (EGO) uses Kriging to reduce the number of simulations by adaptively selecting the simulation point with the largest likelyhood of producing a better component. However, individual simulations are still expensive.


Feedback-Insensitive Integrated Laser

Perry van SCHAIJK*, Daan LENSTRA, Erwin BENTE
University of Technology, P.O.Box 513, 5600MB Eindhoven, The Netherlands

It is well known that semiconductor lasers are highly susceptible to external optical feedback (EOF)[1] which is detrimental to laser performance in many applications. EOF is normally prevented using optical isolators, but these cannot be integrated. Therefore we propose to fabricate an integrated feedback-insensitive laser. Simulations show that such a device can be realized as a ring laser in which the clockwise (cw) and counterclockwise (ccw) modes are not optically coupled. We have studied in detail two configurations of integrated ring lasers that show such characteristics. The theoretical analysis for both configurations is based on rate equations backed up by results from simulation packages.