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The aim of this study was to analyze and compare the accuracy and quality of six 3D printing systems available on the market. Data acquisition was performed with 12 scans of human mandibles using an industrial 3D scanner and saved in STL format. These STL files were printed using six different printing systems. Previously defined distances were measured with a sliding caliper on the 72 printed mandibles. The printed models were then scanned once again. Measurements of volumes and surfaces for the STL files and the printed models were compared. Accuracy and quality were evaluated using industrial software. An analysis of the punctual aberration between the template and the printed model, based on a heat map, was also carried out. Secondary factors, such as costs, production times and expendable materials, were also examined. All printing systems performed well in terms of accuracy and quality for clinical usage. The Formiga P110 and the Form 2 showed the best results for volume, with average aberrations of 0.13 ± 0.23 cm3 and 0.12 ± 0.17 cm3, respectively. Similar results were achieved for the heat map aberration, with values of 0.008 ± 0.11 mm (Formiga P110) and 0.004 ± 0.16 mm (Form 2). Both printers showed no significant difference from the optimal neutral line (Formiga P110, p = 0.15; Form 2, p = 0.60). The cheapest models were produced by the Ultimaker 2+, with an average of 5€ per model, making such desktop printers affordable for rapid prototyping. Meanwhile, advanced printing systems with sterilizable and biocompatible printing materials, such as the Formiga P110 and the Form 2, fulfill the high expectations for maxillofacial surgery.

To ensure the competitiveness of Germany in the manufacturing of composite parts, greater resource efficiency and higher standards of quality are needed. The process of vacuum infusion is used by many companies to produce a great variety of composite parts for markets like shipbuilding, wind energy and many more. Often, those parts have a complex structure requiring a great amount of skill and experience to produce at a high quality. Therefore, the development process often requires several experimental trials before sufficient quality is reached, using up material and time. By using RFID (radio frequency identification) transponders as sensors, the manufacturing process can be monitored, and less reject is produced. When using RFID transponders as sensors, they can then be used to track the component through further assembly steps and as a storage device during the lifetime of the finished product, enabling a simultaneous way of protecting against product piracy and structural health monitoring. The correlation between the RFID signal and the resin state in the fiber layup is shown for several systems. The results show that RFID transponders can be used for both glass and carbon fiber parts to monitor the production process. This will allow a more efficient production of composite parts, shortening process duration and saving resources. The monitoring of the resin flow and cure in the fiber layers underneath an RFID transponder allows the manufacturer to gain information about the state of the process during production. Resin profiles in a thick fiber layup were successfully tracked using an RFID transponder placed above them. The monitoring of the resin in the fiber layers allows the manufacturer to gain information about the state of the process during production. Summarizing the results of our research, the use of RFID transponders as sensors allows an efficient and process friendly monitoring of the resin behavior during vacuum infusion, and the transponders can be further used in logistics. The tracking of the resin behavior beneath a sensor opens up possibilities for further optimization of the part quality.

Bone defects of the craniofacial skeleton are often associated with aesthetic and functional impairment as well as loss of protection to intra- and extracranial structures. Solid titanium plates and individually adapted bone cements have been the materials of choice, but may lead to foreign-body reactions and insufficient osseointegration. In contrast, porous scaffolds are thought to exhibit osteoconductive properties to support bone ingrowth. Here, we analyse in critical size defects of the calvaria in sheep whether different bone replacement materials may overcome those remaining challenges. In a critical size defect model, bilateral 20 × 20 × 5-mm craniectomies were performed on either side of the sagittal sinus in 24 adult female blackheaded sheep. Bony defects were randomised to one of five different bone replacement materials (BRMs): titanium scaffold, biodegradable poly(d,l-lactic acid) calcium carbonate scaffold (PDLLA/CC), polyethylene 1 (0.71 mm mean pore size) or 2 (0.515 mm mean pore size) scaffolds and polymethyl methacrylate (PMMA)-based bone cement block. Empty controls (n = 3) served as references. To evaluate bone growth over time, three different fluorochromes were administered at different time points. At 3, 6 and 12 months after surgery, animals were sacrificed and the BRMs and surrounding bone analysed by micro-CT and histomorphometry. The empty control group verified that the calvaria defect in this study was a reliable critical size defect model. Bone formation in vivo was detectable in all BRMs after 12 months by micro-CT and histomorphometric analysis, except for the non-porous PMMA group. A maximum of bone formation was detected in the 12-months group for titanium and PDLLA/CC. Bone formation in PDLLA/CC starts to increase rapidly between 6 and 12 months, as the BRM resorbs over time. Contact between bone and BRM influenced bone formation inside the BRM. Empty controls exhibited bone formation solely at the periphery. Overall, porous BRMs offered bone integration to different extent over 12 months in the tested calvaria defect model. Titanium and PDLLA/CC scaffolds showed remarkable osseointegration properties by micro-CT and histomorphometric analysis. PDLLA/CC scaffolds degraded over time without major residues. Pore size influenced bone ingrowth in polyethylene, emphasising the importance of porous scaffold structure.

Introduction Treatment decisions for fractures of the orbital floor are based on clinical appearance, ophthalmological examination, and computed tomography (CT) scans. In extensive fractures, decisions are easily made between conservative and surgical treatment. However, objective parameters are rare in inconclusive cases. Materials and methods Our retrospective study included 106 patients with unilateral isolated orbital floor fractures. Correlations between preoperative ophthalmological examinations and specific CT parameters were performed. Results The defect size of the fracture appeared to be significantly associated with the presence of diplopia. CT-morphological parameters and preoperative ophthalmological results showed statistical significance for diplopia and incarceration of inferior rectus muscle (IRM), diplopia and displacement of IRM, decreased mobility and incarceration of IRM, and decreased mobility and displacement of IRM. Discussion Our clinical assessment scheme for CT scans of orbital floor fractures is aimed at facilitating treatment decision making using four CT-based variables. As critical size defects of the orbital floor of ≥2 cm2 are likely to cause clinically significant posterior displacement of the globe, resulting in enophthalmos, the proposed parameters offer a readily accessible and easy to evaluate scheme that helps to identify patients in need of surgical intervention.

In this study, we integrated RFID tags into glass epoxy composites. The RFID tag signal was monitored during resin infiltration and a correlation between resin arrival and a change in the RFID signal could be found. The impact of integrated sensors on the mechanical strength of the composite was investigated. The tensile strength of the composite is unaffected by integrated sensors, while the bending strength is reduced, however, bending deflection is greater in the samples containing sensors, thus avoiding an onset of catastrophic failure at a lower bending deflection in the samples with integrated sensor than in the samples without.

Embedding sensors for in-situ monitoring of composite manufacturing guarantees high quality and cost-optimized products. For minimally invasive sensor integration, the ideal sensors should be made of identical material of the final host product. Frequently, thermoset resins are used for high-performance fibre reinforced composite in aerospace and automotive industries. A thin layer of cured thermoset resin is rigid and brittle and it cannot be reshaped. Thus, it cannot afford to be the substrate of a sensor if flexibility is required. By adding a plasticizer to the resin, a flexible substrate is produced. The substrate is tested to produce a sensor by using a hollow mask to screen-print interdigital structures. This sensor is used to measure the curing of resin during production of Carbon Fibre Reinforced Polymers (CFRP), known to be electrically conductive. Mechanical tests show a better adhesion of the developed substrate to the host structure compared with commonly used polyimide.

Many cells in an organism are exposed to constant and acute mechanical stress that can induce plasma membrane injuries. These plasma membrane wounds have to be resealed rapidly to guarantee cell survival. Plasma membrane resealing in response to mechanical strain has been studied in some detail in muscle, where it is required for efficient recovery after insult. However, less is known about the capacity of other cell types and tissues to perform membrane repair and the underlying molecular mechanisms. Here we show that vascular endothelial cells, which are subject to profound mechanical burden, can reseal plasma membrane holes inflicted by laser ablation. Resealing in endothelial cells is a Ca2+-dependent process, as it is inhibited when cells are wounded in Ca2+-free medium. We also show that annexin A1 (AnxA1), AnxA2 and AnxA6, Ca2+-regulated membrane binding proteins previously implicated in membrane resealing in other cell types, are rapidly recruited to the site of plasma membrane injury. S100A11, a known protein ligand of AnxA1, is also recruited to endothelial plasma membrane wounds, albeit with a different kinetic. Mutant expression experiments reveal that Ca2+ binding to AnxA2, the most abundant endothelial annexin, is required for translocation of the protein to the wound site. Furthermore, we show by knock-down and rescue experiments that AnxA2 is a positive regulator of plasma membrane resealing. Thus, vascular endothelial cells are capable of active, Ca2+-dependent plasma membrane resealing and this process requires the activity of AnxA2.

Microvascular free flaps are considered to be the gold standard in reconstructive head and neck surgery. However, reduced postoperative transplant perfusion is one of the serious postoperative complications and calls for close and reliable monitoring. Procalcitonin, C-reactive protein, and leukocytes are closely associated with local and systemic inflammatory reactions and might have prognostic capacity concerning tissue necrosis. This study aimed to evaluate perioperative serum levels of these three biomarkers to assess their potential in postoperative flap monitoring. A total of 100 patients with microvascular head and neck reconstructions were included in the study. Perioperative serum levels of parameters were measured and the clinical data were analyzed and correlated. A total of 13% of all flaps developed reduced postoperative perfusion. Analysis of the parameters revealed statistically significant differences in the overall patient collective over time, irrespective of clinically reduced flap perfusion. Co-factors such as sex and history of tobacco and alcohol abuse showed significant differences. The efficacy of the parameters in free flap monitoring has not been verified, although the role of procalcitonin in postoperative monitoring, with special regard to the early detection of infections, is underlined by the present study results.

Orbital exenteration (OE) is considered to be a mutilating surgical procedure reserved for relentlessly progressive neoplastic disorders or extensive facial trauma with unfavourable eye involvement. Malignant tumours, accounting for the majority of ablative orbital surgeries, may be caused by primary orbital tumours or secondarily by neoplasias from the surrounding skin, the maxillary sinus or intracranial malignomas. Orbital exenteration following trauma is mostly caused by penetrating globe defects or extended infections with the danger of intracranial effects. Thoughtful resection planning, the exploitation of reconstructive possibilities as well as the consideration of adjuvant therapy are essential to provide the patient with the best available treatment. As a multitude of reconstructive procedures exist, it is of crucial importance to offer a disease-tailored treatment to achieve a successful patient outcome. After retrospective analysis of 45 orbital exenteration cases within the last decade, we developed a defect-driven classification for ablative orbital therapy followed by a guideline for reconstructive procedures. The classification as well as the reconstruction guideline will help the surgeon to restore anatomic boundaries and to promote physiological and psychological recovery for the patient.

Currently, corrosion rates (CR) and/or corrosion products (CP) obtained for methanogen-induced microbiologically influenced corrosion (Mi-MIC) on carbon steel are mainly analyzed from static-incubations. By using a multiport-flow-column, much higher CRs (0.72 mm/yr) were observed, indicating static-incubations are not suitable for determining the corrosive potential of Mi-MIC. With the combination of various analytical methods (ToF-SIMS/SEM-EDS/SEM-FIB) and contrary to previously published data, we observed that CPs contained phosphorus, oxygen, magnesium, calcium and iron but lacked carbon-related species (e.g. siderite). Overall, siderite nucleation is disrupted by methanogens, as they convert aqueous bicarbonate into carbon dioxide for methanogenesis resulting in increased localized corrosion.

Bacterial resistance against antibiotics has become an increasing challenge in the treatment of cutaneous infections. Consequences can be severe, especially in infected wounds following previous local radiotherapy. Certain endogenous peptide antibiotics, the host defence peptides (HDPs), exhibit broad-spectrum antimicrobial activity and promote wound healing. Their use as supplements to conventional antibiotics is a current topic of discussion; however, knowledge of their quantities in healthy and compromised tissue is a prerequisite for such discussion. To date, no data concerning HDP quantities in irradiated skin are available.Expression profiles of the genes encoding HDPs, namely human beta-defensin-1 (DEFB1, hBD-1), beta-defensin-2 (DEFB4A, hBD-2), beta-defensin-3 (DEFB103, hBD-3) and S100A7, were assessed in samples of non-irradiated and irradiated neck.A reduction in the expression of all of the examined genes was observed in irradiated skin when compared with non-irradiated skin (statistically significant in the case of S100A7, P = 0.013). Immunohistochemistry revealed differences in HDP distribution with respect to the epithelial layers.The study demonstrates a significant reduction in HDP gene expression in neck skin as a result of radiotherapy. These findings might represent a starting point for novel treatments of cutaneous infections in irradiated patients, such as topical supplementation of synthetic HDP.

Fiber Bragg gratings (FBG) have attracted interest especially in the field of structural health monitoring (SHM) and online process monitoring. The main objectives of this study are an ultraviolet laser based generation of Bragg gratings in a perfluorinated polymer optical fiber (POF) and their optical, thermo-mechanical and mechanical characterization. This kind of polymer fiber has a higher optical transparency than typical polymer fibers based on polymers with carbon hydrogen bonds like polymethylmethacrylate, which is the most used material for polymer optical fibers to date. Until recently only gratings inscribed by the phase mask technique in thin slabs of the amorphous fluoropolymer CYTOP (cyclic transparent optical polymer) made from polymer fibers were successfully detected. Here infrared spectra of Bragg gratings in the core of perfluorinated polymer optical fibers are presented and the embedding of the bare perfluorinated polymer fibers without the over-cladding (reinforcement) layer are described for the first time. The inscription of the gratings in the core of the polymer optical fiber was done using a krypton fluoride excimer laser (248 nm, 5 eV) and the well-known phase mask method. An advantageous mechanical characteristic of the perfluorinated polymer optical fibers compared to glass optical fibers is the failure strain. In structural health monitoring applications, where strains higher than 10% have to be measured, polymer optical fibers are feasible in contrast to glass optical fibers. The results are also promising regarding stability and reliability. This could open a new field of POF sensing of parts, structures and devices.

Microvascular free flaps are complex but important tools in oral and maxillofacial surgery (OMFS), and though techniques to raise flaps are challenging surgeons often have little structured training. In this study we have evaluated a structured, three-day, hands-on, practical training course on raising flaps. Five human, Thiel-embalmed cadavers were used for training in how to raise the following flaps: radial forearm, anterolateral thigh, lateral arm, fibular, latissimus dorsi, scapular, iliac crest, and rectus abdominis. The total duration of the course was 24 hours over three days. All participants were asked to evaluate the design and conduct of the course, their own learning curve, and general questions about their knowledge of how to raise flaps and microsurgery. There was a significant increase in participants' assessments of how they raised all free flaps, except the lateral arm flap (4.74 (0.68) compared with 2.42 (0.81); p=0.052) before and after the course. The radial forearm flap was thought to be the most relevant in clinical practice (n=40; 75%), followed by the anterolateral thigh (n=5; 9%) and fibular (n=4; 8%) flaps. Comparisons between residents and consultants showed unsurprising differences in experience with microsurgery and self-assessment in raising particular free flaps before the course. We have shown that a structured, hands-on course using a well-established simulation model can significantly improve postgraduate surgeons' skills in raising free flaps.

Objective The limited availability of autogenous oral mucosa in oral and maxillofacial surgery for intraoral grafting after trauma or tumor resection can be balanced by the use of tissue-engineered oral mucosa. However, the use of tissue engineering in autologous grafts is still subject to further research. The aim of this study was to evaluate conditions that lead to a rapid proliferation of vital and highly proliferative oral keratinocytes, which can be used in tissue engineering and consequently help improve surgical management of intraoral mucosal defects. Material and Methods Human oral keratinocytes were obtained from oral mucosal specimens and cultivated. According to their affinity to β1-integrin, epidermal stem cell populations were isolated by using collagen type IV and laminin-coated dishes. Cell proliferation and cell viability were measured by using the CASY cell counter, WST-1 assays, and real-time cell analysis (xCELLigence). Results Measurements on cell proliferation (CASY cell counter) and cell viability (WST-1 assay) showed the characteristic proliferation stages of in vitro–cultivated cells. No statistically significant differences could be monitored (P > .05). Real-time cell analysis, as a more direct and precise technique, revealed a steeper growth curve of adherent cells and therefore generally higher proliferation kinetics compared with cells derived from the supernate. Conclusion Data from real-time cell analysis showed an increased proliferation of adherent cells compared with those derived from the supernate. These results demonstrate the increase of the proliferation capacity by cultivation of keratinocytes derived by adhesion to extracellular matrix proteins.

Surgical treatment of zygomatico-orbital (ZO) fractures is a common procedure in maxillofacial surgery. Often accompanied by pain, trismus and swelling, postoperative morbidity is a major disadvantage, affecting patients' quality of life. The appliance of kinesiologic tape (KT) improves the blood and lymph flow, removing congestions of lymphatic fluid and haemorrhages. The aim of this study was to find out if the application of kinesiologic tape prevents or improves swelling, pain and trismus after zygomatico-orbital fracture surgery, improving patients' postoperative quality of life. A total of 30 patients were assigned for treatment of zygomatico-orbital fractures and were randomly divided into treatment either with or without kinesiologic tape. Tape was applied directly after surgery and maintained for at least 5 days postoperatively. Facial swelling was quantified using a five-line measurement at six specific time points. Pain and degree of mouth opening was measured. Patient's subjective feeling and satisfaction was queried. The results of this study show that application of kinesiologic tape after zygomatico-orbital surgery significantly reduced the incidence of swelling with an earlier swelling maximum, and decreased the maximum turgidity for more than 60% during the first 2 days after surgery. Although, kinesiologic tape has no significant influence on pain control and trismus, mouth opening increased earlier after operation in the kinesiologic tape group compared to the no-kinesiologic tape group. Furthermore, patients with kinesiologic tape felt significantly lower morbidity than those without kinesiologic tape. Therefore kinesiologic tape is a promising, simple, less traumatic, economical approach, which is free from adverse reaction and improves patients' quality of life.

The aim of this study was to evaluate the role of oxidative and nitrosative stress in autogenous bone grafts to the mandible based on immunohistochemical analysis. Material and methods Using a well-established sheep model autogenous bone grafts were harvested form the iliac bone. A combination of a Collagen Membrane (CM) and Deproteinized Bovine Bone Material (DBBM) was used to cover the bone graft (Experiment 2). This modification was compared with simple onlay bone grafts (Experiment 1). Immunohistochemically, the expression of specific stable degradation products of oxidative and nitrosative stress was compared between the two experimental groups. Results Specific markers for oxidative and nitrosative stress showed statistically significant differences in expression in the different experimental groups. The influence of oxidative and nitrosative stress on osteoblasts (OB), osteoclasts (OC), and osteocytes (OCy) was analysed. Experiment 2 showed increased expression of markers in OB and decreased expression in OC. Conclusions Taking the result of this study and reports from the literature into consideration grafts in Experiment 2 showed less resorption and atrophy, higher activity of OB and inhibition of OC, and less expression of Reactive Oxygen and Nitrogen Species (RONS) as markers of oxidative stress within the graft. These data illustrate the improved remodelling processes in grafts using CM and DBBM.

Osteonecrosis of the jaw as a result of treatment with receptor activators of nuclear factor kappa-B ligand (RANKL) inhibitors (denosumab) is a new type of bony necrosis, the exact pathogenesis of which is unknown. Our aim was to find out whether the turnover of bone in the jaw is increased after denosumab has been given compared with other skeletal sites, and if that turnover might have a role in denosumab-related osteonecrosis of the jaw (DRONJ). Bone scintigraphic images of 45 female patients with breast cancer and bone metastases were analysed retrospectively, and divided into 3 groups: those given denosumab, those given a bisphosphonate, and a control group (n=15 in each). All patients had bone scintigraphy before treatment (T0) and during the course of treatment after 12 (T1) and 24 (T2) months. The data were analysed quantitatively using 6 preset bony regions of interest. There was similar turnover of bone in the mandible compared with other skeletal sites (such as the femur), while the maxilla showed significantly higher turnover. None of the bony regions investigated showed any significant changes after the bisphosphonate had been given. There was a tendency to increase bone turnover in those patients taking denosumab. The bone turnover of the jawbone is not overtly changed either by a bisphosphonate or denosumab, so it seems unlikely that oversuppression of bony turnover in the jawbones plays an important part either in the pathogenesis of DRONJ or in the bisphosphonate-related osteonecrosis of the jaw (BRONJ).

Objective Microcirculation and oxygen supply in cervical skin were measured with an optical, noninvasive method in patients with or without radiotherapy before neck dissection. The course of wound healing was monitored after the surgical procedure to identify predictive factors for postoperative wound healing disorders. Study Design Tissue spectrophotometry and laser Doppler flowmetry were used to determine capillary oxygen saturation, hemoglobin concentration, blood flow, and blood velocity at 2-mm and 8-mm depths in the cervical skin of 91 patients before neck dissection in a maxillofacial unit of a university hospital in Munich, Germany. Parameters were evaluated for differences between patients with irradiation (24) and without (67) and patients with wound healing disorders (25) and without (66) (univariate or multivariate statistical analyses). Results Velocity at 2 mm was lower in irradiated skin (P = .016). Flow at 2 mm was higher in patients with wound healing disorders (P = .018). Conclusions High flow values could help to identify patients at risk for cervical wound healing disorders.

This work deals with the ultra violet laser based fabrication of Bragg gratings in perfluorinated polymer optical fibers and their characterization. This kind of polymer fibers shows a higher transparency than typical polymer fibers based on polymers with carbon hydrogen bonds like polymethylmethacrylate, the most used material for polymer optical fibers to date. Up to now only gratings inscribed by the phase mask technique in thin slabs of the amorphous fluoropolymer CYTOP (cyclic transparent optical polymer) made from polymer fibers were successfully detected. Infrared spectra of Bragg gratings in a perfluorinated polymer fiber are presented for the first time here.

Purpose The aim of the present study was to investigate whether the application of elastic therapeutic tape (Kinesio Tape [KT]) prevents or decreases swelling, pain, and trismus after open reduction and internal fixation of mandibular fracture, thus improving patients' postoperative morbidity. Materials and Methods To address the research purpose, the investigators designed and implemented an open-label, monocentric, parallel-group, randomized clinical trial. Patients were prospectively assigned for treatment of unilateral mandibular fractures and randomly allocated to receive treatment with or without KT application. KT was applied directly after surgery and maintained for 5 days postoperatively. Facial swelling was quantified using a 5-line measurement at 6 specific time points. Pain score was assessed using a 10-level visual analog scale; mouth opening was measured. In addition, all patients were asked to evaluate overall satisfaction and swelling (2 groups) and the effect of the tape on movement and comfort (KT group only). Results The study included 26 patients (11 female and 15 male; mean age, 43 yr; standard deviation, 18.5 yr). Application of KT after surgery for mandibular fracture had a statistically significant influence on tissue reaction and swelling, decreasing the incidence of swelling and turgidity by more than 60% during the first 2 days after surgery. Although KT had no significant influence on pain control, patients in the KT group perceived significantly lower morbidity. Conclusion The present results showed that KT after open reduction and internal fixation of mandibular fracture is a promising, simple, less traumatic, and economical approach for managing postoperative swelling that is free from systemic adverse reactions, thus improving patients' quality of life.

Polymeric integrated-optical waveguides are prepared in a planar polymer chip by UV-laser lithographic methods. The waveguide samples are irradiated by an excimer laser at a wavelength Λ =248 nm with various irradiation parameters (different fluencies and irradiation doses). Mach–Zehnder interferometer is employed and the refractive index depth profiles of the waveguide samples are obtained. This profile covers two regions having exponential and Gaussian shapes. The model field distributions strongly depend on the refractive index of each region. The mode field distribution and the effective mode indices for each region have been calculated on the basis of a theoretical model and the experimentally measured data.

It is known that deep ultraviolet (UV) radiation induces a refractive index increase in the surface layer of polymethylmethacrylate (PMMA) samples. This effect can be used for the fabrication of integrated optical waveguides. PMMA is of considerable interest for bio and chemical sensing applications because it is biocompatible and can be micromachined by several methods, e.g. structuring by photolithography, ablation and hot embossing. In the presented work direct UV irradiation of a common PMMA substrate by a krypton fluoride excimer laser beam through a contact mask has been used to write integrated optical Mach–Zehnder interferometers (MZI). MZI are used as sensitive bio and chemical sensors. The aim was to determine contact mask design and laser irradiation parameters for fabricating single-mode MZI for the infrared region from 1.30 μm to 1.62 μm. Straight and curved waveguides have been generated and characterized to determine the optical losses. The generation of channel waveguide structures has been optimized by a two step irradiation process to minimize the lithographic writing time and optical loss. By flood exposure to UV laser radiation in the first step the optical absorption of PMMA can be increased in the irradiated region. The required refractive index profile is then achieved with a second lithographic irradiation. The spectral behaviour of an unbalanced, integrated optical MZI fabricated by this excimer laser based contact mask method is shown for the first time. Further the optical intensity at the output port of a MZI has been measured while the optical path length difference was tuned by creating a temperature difference between the two arms of the MZI.

The optical-functional properties of an integrated-optical strip-waveguide in a planar polymer chip are presented in this article. The waveguide was directly written into the surface of a planar polymer chip by UV-laser irradiation. The refractive index depth profile of the waveguide was examined by a two-beam-interferometric method. Also the mode field distribution and the loss rate of the waveguiding structure has been characterized. The study shows that the optical-functional properties strongly depend on the UV-irradiation parameters. Several mostly independently occurring photochemical processes competing with one another are proposed to explain the formation and shape of the refractive index distribution.

We studied the Rayleigh light scattering and the optical emission in GaAs-(Al,Ga)As superlattices with ordered and intentionally disordered potential profiles, correlated and uncorrelated, in external magnetic fields. We find that the intentional disorder along z affects the resonant Rayleigh scattering and the optical emission. The external magnetic field in the same direction allows to modify the exciton localization and to study the relative modification of the light scattering and of the emission spectra.