Optical components based on waveguides and gratings are in use in several areas of optical communication and
sensor technology. Such structures are realized in both inorganic and organic materials with different more or less
complex fabrication methods. The inscription of optical structures induced by deep ultra violet (DUV) radiation
in homogeneous polymer substrates is a relatively simple lithographic one step process in comparison to other
established fabrication methods. For this technology the irradiation process was enhanced whereby the writing
time was shortened. The writing time to achieve a refractive index change in the order of magnitude of 10-3
is now in the range of a few minutes. Various polymers were investigated and their suitability for waveguide
applications was compared. Some of the polymethylmethacrylate (PMMA) based copolymers have a relatively
high glass transition temperature (Tg) of over 140°C. These optical polymers have the potential to be applied
at higher temperatures than commercial PMMA based polymers. The modification zone was characterised by
several methods. The main points of the work were the determination of the refractive index and the optical loss
of the waveguides. Grating structures were generated by the phase mask method. The optical functionality of
these gratings is described.
Volume holographic gratings have recently attracted interest as wavelength-selective devices, for applications
such as wavelength stabilizers for laser diode sources. These thick gratings are usually produced using various
photosensitive materials like photo-thermo-refractive glass and specially prepared polymers. These materials
often require two or more process steps for production of volume holographic gratings. In this study several
copolymers with MethylMethAcrylate as base material are compared. Unlike commercially available PMMA,
the polymers have a glass transition temperature up to 155 °C, which enables the use on higher laser powers.
The refractive index of the polymer is modified using 325-nm-radiation. The polymers were not sensitized by
peroxidation prior to irradiation, and after the irradiation process, no development was needed. The gratings
were recorded with both a Lloyd mirror setup and the well-known phase mask method. The gratings produced
have a calculated refractive index variation in the range of 10-5. The reflection characteristics were measured
with a modified Michelson interferometer and a tunable laser source. Volume holographic gratings with extremely
narrow bandwidth and angular selectivity can be produced on some of the polymers. The production cost of
the gratings is low and they can be used for multiple applications such as wavelength tuning and wavelength
selection of diode lasers at high power levels.
By UV-laser irradiation the refractive index of some polymers can be locally increased in a controllable way. So by mask lithographic methods integrated-optical waveguiding and dispersive structures can be generated in the surface of a planar polymer chip. Thus a polymeric Bragg-sensor component in integrated-optical form was fabricated by the UV-light of an excimer laser. The surface morphology and optical-functional properties of the polymeric Bragg sensor component have been examined especially in dependence on the irradiation parameters and the temperature. The investigations yield the suitability of the Bragg-sensor for the measurements of temperature and deformation. For the realization of a passive fiber-chip coupling for the integrated-optical components a new technology has been developed and tested. The precise control and high-resolution ablation capability inherent in excimer laser machining make it ideally suited for creating grooves for passive alignment of optical fibers to planar channel waveguides.