InfraTec (Germany)

Abstract A static filter array is developed based on Fabry–Perot cavities operating in the mid‐infrared range from 2 to 4.5 µm, matching the absorption region of several gases relevant for air quality monitoring. The filters include two distributed Bragg reflectors and a high‐index tuning element with varying thickness in between. The filters display high peak transmittance () and controllable peak width. The robustness, ease of fabrication and the possibility to tune the optical response to a specific application make the integrated filter arrays suitable for compact sensing systems.

Nanometer-thin ferroelectric hafnium oxide (HfO 2) films enable manufacturing of integrated infrared sensors in a CMOS compatible process. By depositing the pyroelectric film on an area-enhanced substrate, we significantly improve the sensor element response by a factor of more than 12. Integration challenges of doped HfO 2 in 3D structures are assessed, and the pyroelectric signal amplitude is compared for Si-doped material and the Hf 0.5 Zr 0.5 O 2 mixed oxide.

Abstract Diseases of lung tissue and the airways become a major task for medical care and health care systems in modern industrial countries in the future. Suitable treatment methods and strategies for lung support and artificial ventilation are of dare need. Besides the obvious importance as life-saving intervention, the effects of usually used over-pressure ventilation onto the sensitive alveolar tissue are insufficiently understood. Therefore, it is of great interest to characterize lung tissue during artificial ventilation at the alveolar level. Those measurements can be used to link micromechanics of alveolar structures to mechanical properties of the whole lung like compliance and resistance measured at the ventilator device. This can be done only in animal experiments due to the fact that imaging techniques used in human diagnostics like CT or MRT fail to resolve alveolar tissue structures. The disadvantage of high-resolution techniques like optical coherence tomography (OCT) or intravital microscopy (IVM) is the need of a surgical access to the lung due to the limitation in penetration depth of these techniques. Furthermore, imaging dynamic processes with high-resolution imaging techniques during uninterrupted artificial ventilation is a challenging task. In this study, we present a measurement setup for combined imaging of conventional pressure-controlled ventilated rats and the visualization of volume changes of alveolar structures during one cycle of breath. A custom-made OCT system in combination with a triggered scanning algorithm was used to acquire time-resolved 3D OCT image data. Furthermore, this system was combined with a self-adapting autofocus function for intravital microscopy to track the lung surface keeping the tissue in focal plane. The combination of new dynamic measurement modes for OCT and IVM allows new insights into alveolar tissue and will promote the understanding of mechanical behavior during artificial ventilation.

MEMS tunable Fabry-Pérot filters are a key component for infrared microspectrometers and miniature gas sensors. Compared to other technologies, they have several advantages particularly with regard to miniaturization and optical throughput. This paper gives a short summary of the technology, packaging, system integration and closed loop operation. Several types with different spectral ranges and resolutions will be presented. Possible applications in gas analysis, based on own work and with reference to the literature, are also discussed.

A novel micro-machined chip carrier system for pyroelectric detectors was developed that integrates the sensor elements as well as the infrared filters into one assembly. Based on these chip carriers miniaturized multi-channel detectors with attractive electro-optical parameters especially for gas analysis measurements were engineered.

Paper AIT4B.2

We present the development of a speckle interferometer based on a CO 2 laser and using a thermal infrared camera based on an uncooled microbolometer array. It is intended to be used for monitoring deformations as well as detecting flaws in aeronautical composites, with a smaller sensitivity to displacement compared to an equivalent system using visible (VIS) lasers. Moreover the long wavelength allows working with such interferometers outside the laboratory. A mobile system has been developed on the basis of previous laboratory developments. Then it is validated in a variety of industrial nondestructive testing applications in field working conditions.

Abstract In this paper, investigations on absolute temperature measurements using IR-Thermography of CMOS integrated micro-hot-plates (μHP) are presented. The results of using two different approaches, emissivity correction and black paint coating, are presented and compared with respect to simulation and electrical testing results. In addition, FIB/SEM investigations were used for surface investigations and determination of possible influences to the thermal behaviour by black paint coating process.

We describe three different interferometric techniques (electronic speckle pattern interferometry, digital holographic interferometry, and digital shearography), using a long-wave infrared radiation produced by a CO(2) laser and recorded on a microbolometer array. Experimental results showing how these methods can be used for nondestructive testing are presented. Advantages and disadvantages of these approaches are discussed.

We introduce a poling treatment to induce a single domain structure in [111] single crystals of 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-PT). The properties obtained differ from those known for domain-engineered [111] PMN-PT single crystals. The dielectric, ferroelectric, and pyroelectric properties of this single domain structure are assessed in comparison to polydomain single crystals that were poled by conventional poling treatment. The attributes of the single domain state are a single switching event that reflects in a discontinuity of polarization at the coercive field, a substantially lower dielectric loss (than the multidomain state), and a higher detectivity for pyroelectric applications.