Assessment of irregularities in organic imports from Ukraine to the EU in 2016, notified in OFIS

The underlying study of this report set out to improve the understanding situation concerning residues found in organic food products exported from Ukraine, and to formulate guidelines for identifying and reducing risks for contamination through non-permitted substances based on the results of an in-depth analysis of those residue cases notified in the European Commission’s Organic Farming Information System (OFIS) in 2016. Not surprisingly, the combination of various factors such as (i) the additional sampling required by the new EU import guidelines, (ii) the growing number of exported organic lots from Ukraine, and (iii) the improved analysis technology, led to an increased total number of cases of irregularities notified in OFIS in comparison to previous years. Nevertheless, the number of irregularities in Ukraine in 2016, notified in OFIS, is moderate (affecting estimated < 1% of all exported consignments from Ukraine). Of the lots affected, two thirds were ultimately released as “organic” after additional investigations had been carried out by the respective export CB. Yet, if analysis results of samples taken by the CB’s prior the export, i.e. from crops during the growing season and from lots before they are released for export are included in the risk assessment, Ukraine and its neighbouring countries do need to be considered as relatively high risk countries in terms of contamination and irregularities. It is further interesting to note that the likeliness of residue findings vary a lot among different CBs. The reasons why some CB’s have a high share of residue findings whereas for others proportionally much less residues are found are unclear and should be the subject of further assessments. One assumption is that some CBs took risk-oriented samples whereas others did not. Sampling during the production process (field/leafs and dust) effectively supports organic integrity. Most CB nevertheless focus on residue free final products. The way a CB responds on detected irregularities, i.e. investigates a case and derives “lessons learnt” is very important. A majority of OFIS cases from Ukrainian exports seems to be linked to insufficient management of handling procedure during the storage processes and the transport. However, drift on the field or the intentional use of unauthorised substances are also potential sources of irregularities related to exports from Ukraine. Apart from those cases for which likely root causes have been identified, no clear explanation for discrepancies between lab results between export and import countries could be found for nearly one third of the Ukrainian OFIS cases. Further investigations should be carried out to help identify the reasons for the relatively large differences between the lab results of samples taken from the same trade lots. It is important to better understand these discrepancies in sample measurements because these may lead to significant negative economic impacts for everyone involved in the value chain, even though no rules may have been broken. Another recommendation resulting from this study is to focus more on detecting potential contaminations on the field during the period of crop cultivation. Special attention should be given here to the testing of leaf sample of crops in which contamination has been detected in the past: rapeseeds, sunflower seeds or high quality milling wheat. CB’s should have guidelines on how and when leaf samples should be best taken. Ukrainian organic operators often complain that all Ukrainian operators are put in the same basket and treated as high-risk suppliers. In response to the stricter regulations imposed on them, operators and experts participating in the International Conference “Improving Integrity of Organic Supply Chains” in Odesa 2017 called for an amendment of the inspection policy. Instead of labelling entire countries as high-risk, focus should rather be placed on risky value chains. Supply chains considered high-risk should be relieved from extra measures, once they have demonstrated consistent compliance

New compact pump geometry for thin disk lasers with a tilted optical long-pass filter

Due to the low absorption of pump light in a thin disk laser, the pump light has to be redirected multiple times onto the active medium in order to achieve high pumping efficiency. Therefore, the pump optics in current systems require a large volume compared to the thin disk itself and multiple optics have to be aligned correctly with each other. Our wedged optical lasing chamber for ytterbium disks (WOLCYD) consists of an optical long-pass filter placed at a small angle directly in front of the thin disk. By this, an in-place multiplication of the number of pump passes is achieved. This results in a compact pump optic without the need of sophisticated alignment efforts. We demonstrate a laser oscillator setup and a laser amplifier setup on the basis of the WOLCYD geometry

Ablative collision avoidance for space debris in the Low Earth Orbit by a single multi-kJ pulse from a ground-based laser

We analyze the conceptual idea whether already a single high energy laser pulse, emitted from a laser station on ground, might cause material ablation at the surface of a debris object generating recoil for a sufficiently high velocity change to allow for space debris collision avoidance. In our simulations we assess laser beam propagation through the turbulent atmosphere as well as laser interaction with debris targets of unknown shape and material. The results are discussed in terms of debris displacement, momentum transfer uncertainty, success probability, and limitations due to debris size, mass, and the required laser fluence at the target

Monolithic thin-disk laser and amplifier concept

Thin-disk lasers are indispensable in photonics research as well as in a multitude of industrial applications. They represent a unique class of laser and amplifier architecture that provides kW output power with excellent properties concerning beam quality, long-term stability, thermal management, and power scalability. For many applications, a reduced complexity of the laser and its size would be highly beneficial. The necessary multipass transitions in thin-disk lasers and amplifiers typically require sophisticated multi-mirror arrangements. Here, we present a monolithic version of the pump concept for thin-disk lasers and amplifiers, where the thin disk is replaced by a thin, wedged gain medium acting as a wedged optical trap. The wedge is coated in a peculiar manner in order to allow for efficient in- and out-coupling of the pump and laser radiation from the wedge. This concept transfers the complexity of the multi-mirror optics into the thin disk itself in a monolithic fashion. With this concept, we achieved 890 W of CW output power, 59% slope efficiency, optical-to-optical efficiency of 50%, and a gain factor greater than 10 for small signals. This demonstrates that this new concept is capable of reaching the kW power regime with minimum complexity and size

Power Scaling of Thin Disk laser

realization of lasers with high output power, highest efficiency and good beam quality, simultaneously. The core idea behind the thin disk design is the use of a thin, disk-shaped active medium that is cooled through one of the flat faces of the disk. This ensures a large surface-to-volume ratio and therefore provides very efficient thermal management. The “classical” approach for power scaling of the thin disk design is the scaling of the active area, keeping power densities and pump source brightness requirements constant

2 µm Ho:YAG Thin Disk Laser

A Thulium fiber laser pumped Ho:YAG thin disk laser with 15W (cw) or several mJ (pulsed) operation will be presented. Additionally, a narrow (<0.5nm), tunable (30nm) cw operation near 2.09 µm, will be shown

Thin-disk laser – Power scaling to the kW regime in fundamental mode operation

A significant reduction of the influence of the thermal lens in thin-disk lasers in high power laser operation mode could be achieved, using dynamically stable resonators. For designing the resonator, investigations of thermally induced phase distortions of thin-disks as well as numerical simulations of the field distribution in the resonator were performed. This characterization was combined with thermo-mechanical computations. On the basis of these studies, about 500 W output power with an averaged M2 = 1.55 could be demonstrated, using one disk. Almost 1 kW output power with good beam quality could be extracted, using two disks. For the purpose of further power scaling in nearly fundamental mode operation, experiments using more than two disks are in preparation

Mode Dynamics and Thermal Lens Effects of Thin Disk Lasers

In principle, the thin disk laser concept opens the possibility to demonstrate high power, high efficiency and good beam quality, simultaneously. For this purpose a very homogeneous pump power distribution on the disk is necessary as well as very low phase distortions of the disk itself. Spatial mode structure and thermal lensing effects in an Yb:YAG thin disk laser have been investigated as function of the pump power in linear and folded resonators. Whereas thermal lensing is shown to be very weak due to the thin disk geometry, a strong correlation of the laser mode with respect to the power density distribution of the pump radiation is exhibited. The experimental results are compared with numerical simulations of the field distribution within the resonator as well as in the far field demonstrating the excellent homogeneity of the disk as laser active medium. The results will be used for scaling the fundamental mode power into the multi-kW-regime