Alex Hermanne

Charged-Particle Cross Section Database for Medical Radioisotope Production

Charged-particle cross section database for medical radioisotope production was developed under an international project coordinated by the IAEA. The project focused on radioisotopes for diagnostic purposes and on the related beam monitor reactions. The database contains activation cross-sections of reactions induced by light charged particles with energies mostly up to about 40 MeV. It includes 22 beam monitor reactions for protons (8), deuterons (5), 3He (3) and α-particles (6), and 26 reactions for most commonly used γ-emitters (12), their serious isotopic impurities (4) and β+-emitters (10).

Plastic microoptical interconnection modules for parallel free-space interand intra-MCM data communication

We design and fabricate a prototype scalable multichannel free-space interconnection module with the potential for Tb/s/spl middot/cm/sup 2/ aggregate bit-rate capacity over inter- and intra-MCM interconnection distances. The component is fabricated in a high quality optical plastic, PMMA, using deep proton lithography, an ion-based rapid prototyping technology. As a feasibility demonstration, data communication is achieved at 622 Mb/s per channel with a bit error rate smaller than 10/sup -13/ for 16 channels with an interchannel crosstalk lower than -22 dB. We perform a sensitivity analysis for misalignments and fabrication errors and study the fabrication issues of these components with injection molding techniques. Finally, we provide evidence that these modules can be mass fabricated with the required precision.

Low-cost microoptical modules for MCM level optical interconnections

A multichannel free-space microoptical module for dense MCM-level optical interconnections has been designed and fabricated. Extensive modeling proves that the module is scalable with a potential for multi-Tb/s/spl middot/cm/sup 2/ aggregate bit rate capacity while alignment and fabrication tolerances are compatible with present-day mass replication techniques. The microoptical module is an assembly of refractive lenslet-arrays and a high-quality microprism. Both components are prototyped using deep lithography with protons and are monolithically integrated using a vacuum casting replication technique. The resulting 16-channel high optical-grade plastic module shows optical transfer efficiencies of 46% and inter-channel cross talks as low as -22 dB, sufficient to establish workable multichannel MCM-level interconnections. This microoptical module was used in a feasibility demonstrator to establish intra-chip optical interconnections on a 0.6 /spl mu/m CMOS optoelectronic field programmable gate array. This optoelectronic chip combines fully functional digital logic, driver and receiver circuitry and flip-chipped VCSEL and detector arrays. With this test-vehicle multichannel on-chip data-communication has been achieved for the first time to our knowledge. The bit rate per channel was limited to 10 Mb/s because of the limited speed of the chip tester.

High-precision 2-D SM fiber connectors fabricated through deep proton writing

High-precision two-dimensional (2-D) fiber alignment modules would offer great benefits for high-density photonic interconnects at the multichip-module level, where parallel light signals have to be transferred between integrated dense 2-D emitter and detector arrays, or for massive parallel sensing applications. In telecom, the availability of highly accurate low-cost field installable 2-D fiber couplers would boost the further integration of fiber optics in future fiber-to-the-home networks. We present deep proton writing as a prototyping technology for the mastering of small-form-factor 2-D fiber connector components. The alignment components, which we present here, consist of 4 times 8 arrays of circular conically shaped holes for single-mode fibers and feature average insertion losses of 0.062 dB and a maximum loss of 0.15 dB, when used in a fiber butt-coupling configuration

Refractive-index changes caused by proton radiation in silicate optical glasses.

We have studied experimentally, by using a differential interferometric technique, the effect of proton radiation on the refractive index of commercial (Schott) silicate crown glasses, BK7 and LaK9, and their radiation-resistant counterparts. The strongest effect was observed for the radiation-hard lanthanum crown LaK9G15: At a 0.65-Mrad dose the index change was approximately 3 x 10(-5). Radiation-hard glasses are used in optical systems operating in radiation environments because they prevent spectral transmission degradation in the visible. However, such glasses are not protected against radiation-induced refractive-index perturbations, and a diffraction-limited optical system based on such glasses may fail owing to radiation-induced aberrations.

A single photon spectrometer for biomedical applications

SINPHOS is a monolithic micro-device, able to measure simultaneously time distribution and spectrum of photons coming from a weak source like Delayed Luminescence of biological systems. In order to achieve this challenging goal, we use: Deep Lithography with Ions (DLI) and microelectronic technologies for the fabrication of dedicated passive micro-optical elements and for the realization of Single Photon Avalanche Diode (SPAD) detectors, respectively

Demonstration of a monolithic multichannel module for multi-Gb/s intra-MCM optical interconnects

In this letter, we report on the demonstration of a 2.48-Gb/s multichannel optical data-link for intramultichip module interconnects. The optical module was fabricated in polymethylmethacrylate (PMMA) by deep proton lithography and monolithically integrates micromirrors and cylindrical lenses. With the same technology, we have also fabricated a single-channel optical bridge and used this component to demonstrate a proof-of-principle optical intrachip interconnect by establishing a digital data-link between optoelectronic transceivers integrated on the same chip.

Free-space micro-optical intra-MCM interconnection modules: performances, potentialities and limitations

We design and realize a scalable multi-channel free-space interconnection prototype with the potential for Tb/s.cm2 aggregate bit rate capacity over inter- and intra-MCM interconnection distances. The component is prototyped in a high quality optical plastic, PMMA, using deep lithography with protons. At present data communication is achieved at 622 Mb/s per channel with a BER smaller than 10-13 for the 16 channels with inter-channel cross-talks as low as -22dB. We perform a sensitivity analysis for misalignments and study the impact of fabrication errors on the performance of the interconnection module in case injection moulding would be the preferred mass-fabrication technique. We provide evidence that these modules can be mass-fabricated with the required precision in optical plastics suited for heterogeneous integration with semiconductor materials.

Basic aspects of deep lithography with particles for the fabrication of micro-optical and micromechanical structures

The strength of todays deep lithographic micro-machining technologies is their ability to fabricate monolithic building-blocks including optical and mechanical functionalities that can be precisely integrated in more complex photonic systems. In this contribution we present the physical aspects of Deep Lithography with ion Particles (DLP). We investigate the impact of the ion mass, energy and fluence on the developed surface profile to find the optimized irradiation conditions for different types of high aspect ratio micro-optical structures. To this aim, we develop a software program that combines the atomic interaction effects with the macroscopic beam specifications. We illustrate the correctness of our simulations with experimental data that we obtained in a collaboration established between the accelerator facilities at TUM, LNS and VUB. Finally, we review our findings and discuss the strengths and weaknesses of DLP with respect to Deep Lithography with X-rays (LIGA).

PRODUCTION AND PURIFICATION OF BR-77 SUITABLE FOR LABELING MONOCLONAL-ANTIBODIES USED IN TUMOR IMAGING.

The irradiation of 400 mg As203 with 30 MeV α-particles yields nearly pure Br resulting from the As (a,2n)Br reaction. y-ray spectroscopy of the irradiated material at EOB + 20 h showed that the radionuclidic purity was >99%. The purification of 77Br from the As203 target material is discussed. The irradiated powder is dissolved in boiling water. Anion-exchange column chromatography using Dowex AG 1X8 is performed. The Br is eluted with 1 M NaHSO„. The latter is removed by precipitation with methanol. After drying and redissolving the residue in 100 μΐ of water, a Br solution with pH 6 8 is obtained suitable for the labeling of monoclonal antibodies. Recovery experiments with [As]As203 have shown that after anionexchange chromatography less than 10% of the amount of arsenic is present in the NaHS04 aliquot of interest. The chemical state of the radiobromine is checked by 2 methods: HPLC anionchromatography and TLC. Both techniques proved the Br to exist only in the bromide form.