Densely Integrated Photonic Devices based on Microring Resonators in Access Networks

The application of optical fibers has led to virtually lossless point to point data links in the core network with practically unlimited bandwidth. In response to increasing bandwidth demands of consumers the optical techniques employed in these networks are now gradually extended towards the consumers premises. At the access network level, where equipment is shared by a few users at the most, cost is the major issue. In addition the demand of optical transparency at the nodes and hubs, excluding conversion between the optical and electrical domains, results in a high degree of complexity of the devices. Fortunately, through the use of flexible WDM bandwidth allocation schemes that provide bandwidth where needed, and cheap mass-produced densely integrated optical components, the cost can be reduced significantly. Promising building blocks in these components are Microring Resonators (MRs) built using high refractive index waveguides which can be used to create densely integrated wavelength filters as well as more complex functionality.\ud In this work we present a 1x4 reconfigurable optical add-drop multiplexer (rOADM) as well as a 1x4x4 reconfigurable wavelength router in variants operating in the second and third telecom window. The devices, which can be used at bit rates up to 40 Gbit/s, have a footprint less than 2 mm2 and are based on thermally tunable vertically coupled microring resonators fabricated in the high contrast (Δn≈0.55) Si3N4/SiO2 materials system. In addition to the presented devices a new polarization diversity scheme is proposed that solves the issue of polarization dependence behavior of microring resonators without the need of doubling the optical circuit

An Investigation of the Intrinsic and Extrinsic Influences on the Aggressive Behavior of Crayfish

Several influences have been identified as important in determining aggressive (i.e. agonistic) hierarchy formation in crayfish, however the relative significance of these factors has yet to be determined. This study compares several aggressive influences, including previous winning or losing experiences, prior shelter possession, starvation, olfaction obstruction, and control treatments to determine which of these factors affect aggressive interactions to the greatest extent. The analysis will reveal which of these effects is strongest when directly confronted against one another. Each crayfish received one of the above treatments and then interacts with another size-matched crayfish that received a different treatment. All trials were recorded and then analyzed using a blind analysis scheme. Trials of each experimental treatment versus a size-matched naive crayfish have been completed to date, and the cross-comparison trials are currently in progress

Reconfigurable optical add-drop multiplexer using microring resonators

We report a reconfigurable four-channel optical add-drop multiplexer for use in access networks. The optical add-drop multiplexer (OADM) is based on vertically coupled thermally tunable Si/sub 3/N/sub 4/--SiO/sub 2/ microring resonators (MRs) and has been realized on a footprint of 0.25 mm/sup 2/. Individual MRs in the OADM can be tuned across the full free-spectral range of 4.18 nm and have a 3-dB bandwidth of 50 GHz

Optical network components based on microring resonators

In the last years much effort has been made to arrive at optical integrated circuits with high complexity and advanced functionality for application in optical networks. For this aim high index contrast structures, like optical microresonators, are employed that allow for a large number of functional elements within a given chip area: VLSI photonics. Experimental results of work performed at MESA+ will be reported including a microresonator-based, ultra-compact reconfigurable optical add-drop multiplexer operating at 40 Gbit/s and fabricated in SiON technology. In addition a discussion will be given of new challenges and possible solutions

High index contrast photonics components for optical data communication

Microresonator-based high index contrast integrated optical components show promising performance for the demands of near-future optical networks. Experimental results of an ultra-compact reconfigurable OADM at 40 Gbit/s are presented in detail

Densely integrated photonic devices based on microring resonators for use in access networks

A reconfigurable optical add-drop multiplexer as well as a 1x4x4 reconfigurable λ router, designed for use in the second telecom window, are demonstrated. The devices that each have a footprint less than 2 mm$_{2}$ are based on thermally tunable vertically coupled microring resonators fabricated in $Si_{3}N_{4}$/$SiO_{2}$

Ring resonator enhanced mode-hop-free wavelength tuning of an integrated extended-cavity laser

Extending the cavity length of diode lasers with feedback from Bragg structures and ring resonators is highly effective for obtaining ultra-narrow laser linewidths. However, cavity length extension also decreases the free-spectral range of the cavity. This reduces the wavelength range of continuous laser tuning that can be achieved with a given phase shift of an intracavity phase tuning element. We present a method that increases the range of continuous tuning to that of a short equivalent laser cavity, while maintaining the ultra-narrow linewidth of a long cavity. Using a single-frequency hybrid integrated InP-Si3N4 diode laser with 120 nm coverage around 1540 nm, with a maximum output of 24 mW and lowest intrinsic linewidth of 2.2 kHz, we demonstrate a six-fold increased continuous and mode-hop-free tuning range of 0.22 nm (28 GHz) as compared to the free-spectral range of the laser cavity.Comment: 12 pages, 7 figure