Silicon nitride waveguide optical filter components for access network applications

• Main Author: Bedi, Saurabh
• Format: Article in Journal/Newspaper
• Language: English
• Published: École de technologie supérieure 2018
• Subjects: résonateur en anneau; guide d'onde en nitrure de silicium; chirp géré laser; l'effet de Vernier; NGPON-2; anneau réflecteur; The ''Y''; DML
• Online Access: https://espace.etsmtl.ca/id/eprint/2196/; https://espace.etsmtl.ca/id/eprint/2196/1/BEDI_Saurabh.pdf; https://espace.etsmtl.ca/id/eprint/2196/2/BEDI_Saurabh-web.pdf

Silicon nitride (SiN) waveguide based micro ring/racetrack resonators to be used as filters in the Chirp Managed Lasers (CMLs) are modelled and demonstrated over the standard silicon (Si) wafer. The development of these racetrack-resonators, with a narrow free spectral range (FSR) of 100GHz is in correspondence to the international telecommunication union (ITU) recommended channel grid spacing required for the latest next generation passive optical networks (NGPON2) systems. The study of such optical filters, which tend to increase the transmission range of the directly modulated laser (DML) signal, is motivated from the research and development directed towards bringing the CMLs to a reality. Also, a single SiN ring resonator and a silicon waveguide based cascaded 3-ring design, both integrated within the Y-splitter configuration are presented to be used as a reflector in external cavity laser. These ring reflectors are designed to have a broad FSR, which is achieved using the Vernier effect by serially coupling three racetrack resonators. In this thesis, we analyze and optimize the optical response of the above mentioned devices based on SiN waveguides deposited over silicon wafers. The design parameters are optimized based on analytical modelling and simulations are carried out with finite difference time domain (FDTD) solver. The devices are fabricated in different labs and clean room facilities within Montreal in collaboration with our industrial partner AEPONYX. The performance of these fabricated devices is characterized using an optical test setup in university lab facilities. The simulation and the measurement results are in close proximity for a large 4-port add-drop racetrack resonator, giving a FSR close to 100GHz specified for the NGPON2 systems and an extinction ratio (ER) of >15 dB to be useful for modulating the inherent chirp of the directly modulated lasers (DML) and thereby increasing the transmission range of the data signals. For the Si waveguide based cascaded 3rd order ring reflector, a ...