The fabrication of optical interconnects has been widely investigated for the generation of optical circuit boards. Twophoton absorption (TPA) lithography (or high-precision 3D printing) as an innovative production method for direct manufacture of individual 3D photonic structures gains more and more attention when optical polymers are employed. In this regard, we have evaluated novel ORMOCER-based hybrid polymers tailored for the manufacture of optical waveguides by means of high-precision 3D printing. In order to facilitate future industrial implementation, the processability was evaluated and the optical performance of embedded waveguides was assessed. The results illustrate that hybrid polymers are not only viable consumables for industrial manufacture of polymeric micro-optics using generic processes such as UV molding. They also are potential candidates to fabricate optical waveguide systems down to the chip level where TPA-based emerging manufacturing techniques are engaged. Hence, it is shown that hybrid polymers continue to meet the increasing expectations of dynamically growing markets of micro-optics and optical interconnects due to the flexibility of the employed polymer material concept.

Additive manufacturing has set out to change the world of manufacturing, and is also addressing the space of optical network components. Developments for industrialization of two-photon absorption processing will be displayed targeting current prototyping of test structures and future options for volume manufacturing of optical components and network technology.

We address the feasibility of free-form laser-printed 3D structures for sub-μm to large area fabrication. The impact of material and process parameters for different applications in photonics, micro- and organic electronics and life-science is discussed.

The state of the art of three newly developed measuring techniques for the determination of polycyclic aromatic hydrocarbons in flue gas is described: The photoelectric aerosol sensor (PAS), the ATLAS LIFE sensor system and the emission mass spectrometer (EMS). The measuring principle of each system as well as the practical experiences made with the measuring devices at different emission sources are presented.

The state of the art of three newly developed measuring techniques for the determination of polycyclic aromatic hydrocarbons in flue gas is described: The photoelectric aerosol sensor (PAS), the ATLAS LIFE sensor system and the emission mass spectrometer (EMS). The measuring principle of each system as well as the practical experiences made with the measuring devices at different emission sources are presented.

The state of the art of three newly developed measuring techniques for the determination of polycyclic aromatic hydrocarbons in flue gas is described: The photoelectric aerosol sensor (PAS), the ATLAS LIFE sensor system and the emission mass spectrometer (EMS). The measuring principle of each system as well as the practical experiences made with the measuring devices at different emission sources are presented.

The continuous detection of polycyclic aromatic hydrocarbons (PAH) is an important task for efficient environmental protection. STN ATLAS Elektronik is developing a fully automated sensor system for registration of different gaseous and particle bound PAH in stack gases of combustion processes. As measuring principle, laser-induced fluorescence analysis is used. Two parameters, the decay time and the wavelength of the fluorescence are recorded and evaluated for the classification of the different PAH. The sensor system and the newly implemented data analysis are described. Results of measurements in the exhaust gases of different industrial plants are revealed.

We address the problem of estimating the components of superimposed exponentially decaying signals. Usual estimation techniques, e.g. least squares or eigenvalue and eigenvector based methods, are not adequate for exponentionally decaying fluorescence processes due to their rather simple signal modelling. Therefore, we introduce a better suited parametric model by exploiting the statistical properties of the exponentially decaying emission of fluorescence photons (time dependent Poisson statistics). Using this model maximum likelihood estimates for the fluorescence intensity spectrum and the decay parameters are derived. The performance of the maximum likelihood estimates is compared with the least squares estimates by means of simulations and real data experiments. The results indicate the superiority of the maximum likelihood estimates.

The 'on line' and 'in situ' detection of polycyclic aromatic hydrocarbons (PAHs) in exhaust aerosols of combustion processes is still one of the important tasks in analytical chemistry. Accordingly, within the framework of a scientific project with the financial support of the German Minister for Education, Science, Research and Technology, STN ATLAS Elecktonik GmbH, Bremen, is developing a fully automatic sensor system for the detection of PAHs absorbed on particles in exhaust aerosols. Time-resolved spectra of laser-induced fluorescence are measured. Two parameters, the decay time and the wavelength of the fluorescence are recorded and evaluated for the classification of different PAHs. In this paper the sensor system is described in detail and results of measurements in the exhaust gases of various industrial plants are shown.

Laser-induced and time-resolved aerosol fluorescence is introduced as an analytical technique for the qualitative and quantitative determination of surface-bound polycyclic aromatic hydrocarbons (PAHs). The analytical figures of merit are evaluated by studying the fluorescent properties (emission wavelengths and temporal behavior) of PAHs adsorbed on submicrometer NaCl particles. In addition to singly adsorbed PAHs on NaCl particles, a three-component PAH adsorbate system is characterized. Detection limits are in the range 5 ng/m3 (e.g. for anthanthrene).

Laser-induced fluorescence is introduced as an analytical technique for the detection of particle-bond PAHs, which can be found as a result of most combustion processes. A quartz fiber is used to couple the light of a frequency-doubled excimer-pumped dye-laser into the sensor head. The fluorescence light is detected using collecting optics, a set of interference filters and a photomultiplier. PAHs in different forms (crystalline, in solution, as homogeneous particles and coated on NaCl particles) were investigated. Fluorescence spectra and time-resolved signals, which exhibit characteristic decay times, are presented.