This thesis will describe the design, realization and characterization of an EO polymeric MR resonator, which was fabricated in the framework of a MESA+ Strategic Research Orientation TeraHertz and an IST project NAIS. The thesis is organized in the following chapters.
A short introduction of the two projects for which the work of thesis was done is given, after which the device principles of two different device variations are discussed. Each of the two projects sets different demands for the structure to be realized and the difference between these two projects will be discussed briefly.
In order to predict the behaviour of the EO MR modulator, the theoretical background of the device is discussed. The first part of the chapter deals with polymer related theory, in which the different properties of polymers and the basic structure of the active polymer are discussed. The second part of the chapter deals with the theoretical description of both the MR and the MR-MZI device.
With the theoretical descriptions from the previous chapter, a design of the modulator was made. The first part of this chapter describes the choice for the different materials used in the device. The properties (refractive index + spincurve) of these materials are determined in this part of the chapter. The second part of the chapter deals with the dimensions of the complete device and both 2D and 3D simulations for both waveguide and MR are done. The electrode structure is designed and the different mask-layers are discussed.
The realization of the designed device is discusses in this chapter. First the different fabrication steps in the process are summarized, after which the second part of the chapter deals with different problems/issues that arose during the fabrication process. A description of each issue is given, with a solution for the problem that this issue causes. The problems are discussed in chronological order in the fabrication process.
After realizing the devices, characterization is needed in order to confirm their behaviour. Different measurement techniques that were used to determine material or waveguide properties are discussed. The measurements of realized devices are discussed in the second paragraph of the chapter. First the passive MR behaviour is measured, after which from these measurements conclusions can be drawn about the dimensions and properties of it. Fitting software [RFIT] is used in order to determine the loss in the MR and the distance between MR and waveguide. Thermo optic tuning of a single MR is done by heating the entire structure and looking at the spectral shift. On these single MRs 50 MHz EO modulation is measured. On an MR device combined with an MZI, EO modulation up to 1GHz could be measured. The reason for the relatively low 50 MHz on the single MR is partly explained in the last paragraph in which photo-stability measurements are done.
Conclusions regarding the fabrication and characterization process will be drawn in this chapter and also some recommendations for any future work on the subject of this thesis will be given.