In this work different fibre optic sensors for the structural health monitoring of civil engineering structures are reported. A crack sensor and two moisture have been designed to detect ingress in concrete based building structures. Moreover, degeneration mechanical properties optical glass hence their long-term stability reliability due chemical impact environment is discussed as well advantage applying a system sewerage tunnels demonstrated.

For various applications such as optical communication, sensor technology, and interconnects, microoptical polymer devices show great promise. Especially, straight bent waveguides well beam splitters represent the building blocks of these devices. In this paper, we introduce a novel combination simple fabrication techniques cost-efficient materials for planar waveguides. We present low-cost process through hot embossing doctor blading investigate use UV curing printing ink adhesive waveguide...

The generation of diffractive optical elements often requires time and cost consuming production techniques such as photolithography. Especially in research development, small series microstructures are needed flexible effective fabrication desirable to enable the versatile on a short scale. In this work, we introduce novel process chain for various polymers. It is based maskless lithography step, where computer generated image element projected via digital mirror device microscope setup...

A new multimodal system for rapid, noninvasive in vivo skin cancer screening is presented, combining optical coherence tomography (OCT) and optoacoustic (OA) modalities to provide precise tumor depth determination with a Raman spectroscopic modality capable of detecting the lesion type and, thus, providing diagnostic capability. Both OA setups use wide field illumination ensure compliance maximum permissible exposure (MPE) requirements. The signal collected via OCT scanning lens maximize...

A reliable, fast, and non‐invasive determination of melanoma thickness in vivo is highly desirable for clinical dermatology as it may facilitate the identification surgical margins, determine if a sentinel node biopsy should be performed or not, reduce number interventions patients. In this work, optical coherence tomography (OCT) high frequency ultrasound (HFUS) are evaluated quantitative preoperative assessment skin infiltration depth melanocytic tissue. Both methods allow imaging at...

Optical aberrations of microscope lenses are known as a source systematic errors in confocal surface metrology, which has become one the most popular methods to measure topography microstructures. We demonstrate that these not constant over entire field view but also depend on local slope angle microstructure and lead significant deviations between measured actual surface. It is shown by means full vectorial high NA numerical model change alters shape intensity depth response leads shift...

Micro-optical sensors integrated into polymer foils hold great promise for a wide range of applications. One major challenge to date is the reliable, large-scale and cost-effective manufacturing required waveguide structures. Several techniques are currently investigated in field, hot-embossing being particularly promising. In this work, we discuss hot embossing optical waveguides. We present our recent results area stamp fabrication. For characterization waveguides, refractive index,...

Low-loss optical-coupling structures are highly relevant for applications in fields as diverse information and communication technologies, integrated circuits, or flexible highly-functional polymer sensor networks. For this suitable reliable production methods crucial. Self-written waveguides an interesting solution. In work, we present a simple efficient one-polymer approach self-written optical connections between light-guiding such single-mode multi-mode fibers that relies on self...

We describe a novel technique for determination of the refractive index hard biological tissue as well nonopaque technical samples based on optical coherence tomography (OCT). Our method relies an inverse refractive-index correction (I-RIC), which matches measured feature geometry distorted due to boundaries its real geometry. For known geometry, can be determined with high precision from best match between and corrected images. provide experimental data measurements polymethylmethacrylate...

Confocal microscopy is one of the dominating measurement techniques in surface metrology, with an enhanced lateral resolution compared to alternative optical methods. However, axial confocal strongly dependent on accuracy signal evaluation algorithms, which are limited by random noise. Here, we discuss influence various noise sources intensity evaluating including center-of-mass, parabolic least-square fit, and cross-correlation-based We derive results closed form for uncertainty height...

Optical interconnects are the key components for integrated optics to link photonic circuits or connect external elements such as light sources and detectors. However, misalignment of optical contained its compensation is a remaining challenge devices. We present novel method establish rigid based on 2-wavelength self-written waveguide process which automatically compensates misalignment. exemplarily demonstrate capability our by writing between two multimode fibers well hot-embossed polymer...

Novel concepts for a planar optical deformation measurement promise broad application potential in fields such as structural health monitoring, process control, or life sciences. In this paper, we present new approach to displacement and tilt sensing thin polymer foils. We report on the design, simulation, realization, characterization of an all-polymer strain sensor based simple principles. The relies evaluation coupling efficiency between two arrays emitting receiving waveguides. As...

For sensing applications in structural health monitoring, process technology or life sciences polymer micro-optical sensors are highly promising as they offer several advantages comparison to other sensor types. In this work, a fabrication of low-cost planar optical waveguides based on hot embossing and doctor blading is presented. Such represent one the main building blocks systems. The refractive index propagation losses waveguide materials characterized. order increase integration density...

Optical transmission paths consisting of waveguides, light sources, and detectors form basic components in a large variety applications ranging from photonic sensors to short distance communication. We demonstrate the design fabrication polymer path, which incorporates standard semiconductor sources. In this paper, we especially focus on low-cost such systems including easy-to-fabricate optically efficient coupling structures. Our concept relies self-written waveguide interconnects, can be...

Advances in illumination technology the automotive industry are heading toward use of coherent sources for adaptable and high-resolution head lamps as well interior rear-end lights. We present a cost-effective method to fabricate design laser-based lighting systems rear end automobiles other vehicles. The relies on using binary gratings generate desired intensity distribution. For fabrication, an optical maskless UV lithography system that employs spatial light modulator (SLM) projection...

Polymer-based holographic and diffractive optical elements have gained increasing interest due to their potential be used in a broad range of applications, such as illumination technology, micro-optics, holography. We present production process fabricate polymer-based holograms. The is based on maskless lithography, which photoresist. discuss several lab-level lithography setups digital mirror devices liquid crystal with respect efficiency, resolution, contrast. entire setup designed...

To produce diffractive or holographic structures in a photolithographic process, an optical projection system enabling structure resolution the submicrometer range is highly desirable. ensure that focus of such lies on substrate surface during whole lithographic fabrication autofocus able to depth field few hundred nanometers usually required. In this work, we developed for spatial light modulator (SLM)-based maskless applications. The capable high-precision focusing without affecting...

In the past years, several examples of waveguides or gratings manufactured by laser radiation in various glasses transparent polymers have been demonstrated. As these devices rely on a modification refractive index vicinity focal point writing laser, phase retrieval methods are well suited to determine induced change inside material experimentally. Thus, can assist parameter-studies and reveal information about internal structure modifications which hardly be obtained using other methods....

We present a simple and efficient Monte Carlo model to predict the scattering coefficients influence of multiple photon with increasing concentration centers from optical coherence tomography (OCT) data. While reliably estimates sample parameters for broad range concentrations, it does not require inclusion more complex phenomena such as dependent scattering. Instead, relies on particular weighting function which is introduced describe various orders events. In weakly homogeneous media...

Circumferential scanning in endoscopic imaging is crucial across various disciplines, and optical coherence tomography (OCT) often the preferred choice due to its high-speed, high-resolution, micron-scale capabilities. Moreover, real-time high-speed 3D endoscopy a pivotal technology for medical screening precise surgical guidance, among other applications. However, challenges such as image jitter non-uniform rotational distortion (NURD) are persistent obstacles that hinder visualization...

Colonoscopy and endoscopic ultrasound play pivotal roles in the assessment of rectal diseases, especially cancer inflammatory bowel diseases. Optical coherence tomography (OCT) offers a superior depth resolution, which is critical factor for individualizing therapeutic concept evaluating therapy response. We developed two distinct rectoscope prototypes, were integrated into 1300 nm MHz-OCT system constructed at our facility. The rapid rotation distal scanning probe 40,000 revolutions per...

We present a novel one-step calibration methodology for geometrical distortion correction optical coherence tomography (OCT). A standard especially designed OCT is introduced, which consists of an array inverse pyramidal structures. The use multiple landmarks situated on four different height levels the pyramids allow performing 3D calibration. procedure itself based parametric model beam propagation. It validated by experimental results and enables reduction systematic errors more than one...

Micro-optical sensors based on optical waveguides are widely used to measure temperature, force and strain but also detect biological chemical substances such as explosives or toxins. While micro-sensors silicon technology require complex expensive process technologies, a new generation of completely polymers offer advantages especially in terms low-cost fast production techniques. We have developed integrate micro-optical components embedded interconnects into polymer foils with thickness...