Edwin Jan Klein - Universiteit Twente

9
Introduction
these basic parameters into actual resonator designs are given for a laterally
and a vertically coupled resonator. Apart from the design of the resonators
some important issues related to overall device design, up to the prototype
level, are also be discussed.
• In Chapter 4 some of the tools that were created to aid in the design and
characterization of microring resonator based devices are presented. In
particular the analytical and numerical methods used to fit measured resonator
responses are examined in detail. Aurora, a tool created to perform simulations
on complex optical circuits containing resonators, is also discussed in this
chapter.
• In Chapter 5 the fabrication processes used to fabricate the various devices
presented in this thesis are described in detail. Also the implications that a
certain process has on the design of the masks used in that process are
discussed.
• In Chapter 6 a specific design for a basic resonator building block is given.
This building block consists of a single thermally tunable resonator and was
used as the fundamental unit (i.e. the same resonator design was used many
times) in the OADM and Router discussed in Chapter 7. Some important
aspects in the design of a resonator building block are illustrated using the
wavelength response and thermal tuning measurements on a number of
(steadily improving) resonator designs. Also presented are the wavelength
selective switch and a Vernier filter based on two resonators.
• In Chapter 7 the design and characterization of two different types of OADM,
for use at 1310 nm or at 1550 nm, and a Router are discussed. For 1550 nm
OADM system level measurements performed at 40 Gbit/s are also presented.
• A major problem of microring resonator based devices is that it is often very
difficult to make them polarization independent. Although this can by solved
by introducing polarization diversity in the devices this doubles the number of
resonators in the devices and creates a number of new problems. In Chapter 8
a method is described for creating a polarization diverse device that does not
double the number of resonators and that also has several other advantages.
• Finally, in Chapter 9, general conclusions based on the work presented in this
thesis will be drawn.