Reports in 1982 of polymers ablated and etched by excimer laser radiation mark the founding of laser microfabrication as a technology that in the intervening period has matured into a manufacturing process used by a diverse range of industries. This paper reviews the historical developments of laser microfabrication, highlights some of its current important industrial applications and takes a forward look at possible developments of the technology.

Phase explosion and Marangoni flow during laser micromachining of thin metal films are studied in this paper. The purpose of this study was to improve understanding of the time scales by which these processes occur. The study was based on a time-resolved reflection imaging method. The method used a nitrogen-pumped dye laser to illuminate the surface of the films at a given time after the Nd:YAG laser heats the film. The dye laser irradiation reflected from the surface was then imaged by a CCD camera. The lasers were coupled by a digital pulse-delay generator, allowing the time delay between the two lasers to be controlled by the user. The effects of Marangoni flow and phase explosion can be seen on the starting and ending times of ablation. At all fluences in the study, holes were opened in the aluminum films and the hole formation process was completed in under 350 ns. Ablation of nickel films was very different however, with thin layers of the film surface removed at low fluences, a process which took on the order of microseconds to complete. At higher fluences the nickel films ruptured and the hold opening process was completed in less than 500 ns.

The results of a comparative investigation on the emission characteristics of debris from CO₂ laser-produced tin plasma and Nd: YAG laser-produced tin plasma for an extreme ultraviolet lithography (EUV) light source. The tin ions and droplets emitted from tin plasma produced by a CO₂ laser or an Nd: YAG laser were detected with Faraday cups and quartz crystal micro-balance (QCM) detectors, respectively. The large size of droplets was also observed by silicon substrates as witness plates. A higher ion kinetic energy and lower debris emission in the case of CO₂ laser in compared with Nd: YAG laser for the same laser energy of ~50 mJ. In addition, the dynamics of the neutral atoms and the irradiated target from an Nd:YAG laser-produced tin plasma with a mass-limited micro-droplet target were investigated by imaging techniques.

We have investigated a one-step method to fabricate a microstructure on a silica glass plate using laser-induced backside wet etching (LIBWE) upon irradiation with DPSS (diode-pumped solid state) lasers. Well-defined deep microtrenches without crack formations on a fused silica glass plate were fabricated by LIBWE method. As the laser beam of DPSS UV laser at a high repetition rate up to 5 - 100 kHz is scanned on the sample surface with the galvanometer controlled by a computer for flexible operations, galvanometer-based point scanning system is suitable for a rapid prototyping process according to electronic design data in the computer. The behavior of liquid ablation (explosive vaporization) was monitored by impulse pressure detection with a fast-response piezoelectric pressure gauge. LIBWE method is suitable for rapid prototyping and rapid manufacturing of surface microstructuing of silica glass as mask-less exposure system in a conventional atmospheric environment.

Fabrication of wafers with built-in areas of different bandgap materials is of paramount importance for the technology of monolithically integrated devices. Numerous approaches have been proposed and investigated in literature to address this problem especially in III-V basedsemiconductor microstructures. We report on an innovative technique of post-growth selective area bandgap engineering of InGaAsP/InP quantum well (QW) microstructures that is based on infrared laser rapid thermal annealing (Laser-RTA). The method makes use of a 150 W 980 nm laser for background heating of wafers to just below the threshold for quantum well intermixing (QWI) temperatures. Another infrared source, a 30 W TEM00 Nd:YAG laser, is used to increase the temperature above the QWI threshold that leads to the fabrication of different bandgap material. The Laser-RTA technique allows for a significant reduction in the risk of damaging the surface of a semiconductor wafer heated to high temperature with one laser source. Also, it has the potential to fabricate almost arbitrary shaped lines of bandgap engineered material. For the investigated GaInAsP/InP QW microstructures, we have achieved bandgap shifts in excess of 200 nm. We discuss advantages that the proposed Laser-RTA technique offers in the fabrication of monolithically integrated photonic devices.

Photostructurable glass-ceramics (PSGCs) present an attractive alternative to silicon as substrates for microfabrication. Moving a laser beam with a focal volume a few microns across and a few tens of microns high through a transparent PSGC induces a cascade of reactions that results in selective crystallization in the laser-exposed regions. The process offers excellent 3-D shaping control. Crystal formation alters many material properties, including opacity, index of refraction, etch rates, density, stiffness, and strength. Presented here are the results of bulk mechanical measurements of the mass density and the velocity of sound in several phases of Foturan, a commercially available PSGC. The measurements are nondestructive and easily repeatable at many stages of processing. From the velocity and the mass density, we calculated the elastic modulus for each Foturan phase. The measured samples included native, amorphous Foturan; exposed Foturan that was not thermally treated; and exposed, thermally treated Foturan. Results show that Foturan becomes somewhat stiffer with higher crystal content; the elastic modulus of Foturan rises from about 78 GPa in the original amorphous glass state to about 88 GPa in a crystal-rich, exposed, baked state. The speed of sound in Foturan rises from about 5.8 km/s to 6.1 km/s.

By the use of stroboscopic laser pump - x-ray probe techniques and x-ray scanning techniques the structural relaxations of gold nanoparticles have been resolved on the 50 ps time scale. The structural dynamics are addressed by several methods including power scattering and small angle scattering (SAXS) to resolve microscopic and mesoscopic length scales of the composite system. The laser power is a direct measure of the dissipated heat. Thus the caloric reaction and melting transition can be monitored as function of temperature, particle size and time. Nonlinear effects are observed with femtosecond excitation, attributed to ablation. While the phenomenology for nanoparticle suspensions and surface supported monolayers display similar energetics, structure formation processes are strongly altered on the surface due to interparticle interactions.

Using a picosecond laser system that can operate at 1064, 532, 355, and 266nm wavelengths, experiments were conducted with polished metal samples to study material removal from a low number of laser pulse exposures. The samples were analyzed with a scanning electron microscope and white light interferometer to gather data on surface deformation and material removal. The effects of wavelength, energy and a double pulse exposure method were examined. Results were compared with simulations that model the material removal rates from ultrashort pulse drilling.

Optical waveguides with a propagation loss of around 0.5 dB/cm are written inside photosensitive Foturan glass by internal modification of refractive index using femtosecond (fs) laser. Integration of the optical wafveguides with a micromirror enables us to bend the guided laser beam at an angle of 90° with a bending loss of less than 0.3 dB. In the meanwhile, a plano-convex microlens is completely embedded inside the Foturan glass chip via formation of a three-dimensional (3D) hollow microstructure using fs laser direct writing followed by heat treatment and successive wet etching. This technique can also be used to fabricate microfluidic devices and therefore realizes 3D integration of microoptical and microfluidic components by one continuous procedure. Subsequently, microoptical waveguides are further integrated into the single glass chip. Demonstration of optical measurements using the integrated microchip reveals that photonic biosensing can be performed with an efficiency increased by a factor of 8 for fluorescence detection and by a factor of 3 for absorption detection.

Sub wavelength ripples (spacing < λ/4) perpendicular to the polarisation of the laser radiation are obtained by scanning a tightly focused beam (~1μm) of femtosecond laser radiation from a Ti:Sapphire laser (τ=100fs, λ=800nm & 400nm, f=1kHz) and from a Yb:glass fiber laser (τ=400fs, λ=1045nm, f=0.1-5MHz) over the surface of various materials like amorphous Nd:Gd₃Ga₅O₁₂ films 1 μm in thickness on YAG substrates, diamond, polytetrafluoroethylene, LiF, MgF₂, ZBLAN, Al₂O₃, LiNbO₃, SiO₂, Si, Cu and Au. The ripple patterns extend coherently over many overlapping laser pulses and scanning tracks. Investigated are the dependence of the ripple spacing Λ on the material, the lateral distance of the laser pulses, the N.A. of the focussing optics, the repetition rate and the applied wavelength. The ripples are characterised using electron microscopy. Some possible models for the origin of the ripple growth are discussed. New results concerning the scaling of the production process using a high repetition rate laser and a fast translation stage are demonstrated. The cross-sections of the ripples are investigated using electron microscopy. A very large aspect ration of ~10 is observed for the periodical nanostructures in fused silica. Using in-volume selective laser etching (ISLE) of sapphire results in deep hollow nanoplanes ~200 nm in width and up to 1 mm in length. Microchannels have been produced using in-volume selective laser etching with a scanning speed of 1 mm/s.

Application of lasers for print form fabrication plays an increasingly important role in the printing industry due to the high machining rate, the high spatial resolution and the ability of digital modulation. This paper gives an overview of our laser based processes in gravure and embossing with a focus on micro-structuring of gravure print forms by direct laser ablation. The precise large scale micro-fabrication by laser engraving is the fastest and most versatile process for gravure cylinder fabrication (ablation rate up to 1 cm³/min). Direct laser engraving into metallic cylinders is performed with high power Q-switched Nd:YAG laser systems and fiber lasers at up to 100 kHz repetition rate, tuned for high reproducibility and stability of the mean pulse energy (σ² < 0.6%). Flexible aspect ratios and designs of the cell profile are achieved by fast modulation of the laser beam profile for each single pulse. This allows for optimization of the cell shape to get the best ink transfer interaction on a specific print substrate. New experiments with high power fiber lasers (cw lasers and pulsed MOPA systems > 500W@ 100kHz) resulted in improved cell precision, screen resolution and production efficiency. Future large scale cylinder engraving with ultra short pulse lasers (ps) is discussed.

Advanced laser crystallization of Si for flat panel displays demands a narrow line-shaped light focus with an ultimately high homogeneity. Key element of LIMO line shaping system is an anisotropic quality transformation of a multimode laser beam, which permits a very good homogenization for the long axis and tight focusing with a large depth of focus for the perpendicular high-quality axis. A prototype system has been built with a 90-W 532-nm DPSS laser. It provides a 59-mm long and down to 8 μm (FWHM) narrow focus with a residual inhomogeneity of only 1% (rms). The focus width is adjustable and its shape can be tuned from a quasi-Gauss to a top-hat intensity distribution. The depth of focus at 90% of the peak intensity DOF_0.9I varies from 120 μm for a line width of 8 μm to 275 μm for FWHM = 14 μm. The design of longer lines is in progress at LIMO.

Refractive, diffractive and reflective micro-optical elements for laser beam shaping and homogenizing have been manufactured and tested. The presented multifunctional optical elements are used for shaping arbitrary laser beam profiles into a variety of geometries like, a homogeneous spot array or line pattern, a laser light sheet or flat-top intensity profiles. The resulting profiles are strongly influenced by the beam properties of the laser and by diffraction and interference effects at the micro-optical elements. We present general design rules for beam shaping and homogenizing. We demonstrate the application of such multifunctional micro-optical elements for a variety of applications from micro-laser machining to laser diagnostic systems.

We present newly developed high power diode laser modules which are performing at outstanding power densities and line uniformity. The combination of recently designed laser diode bars on passive heat sinks and optimized micro-optics results to laser modules with power densities > 100kW/cm² in a line length of 12mm x 0.1mm. The usage of non periodic structured homogenizers leads to a homogeneity of less than 3% p/v which allows precise heating and annealing applications. The application for such laser lines are hardening, metallization and annealing of different materials. In the presentation we will show results of thin film Si-a annealing process with direct diode laser annealing.

Laser micromachining by ablation is a well established technique used for the production of 2.5D and 3D features in a wide variety of materials. The fabrication of stepped, multi-level, structures can be achieved using a number of binary mask projection techniques using excimer lasers. Alternatively, direct-writing of complex 2.5D features can easily be achieved with solid-state lasers. Excimer laser ablation using half-tone masks allows almost continuous surface relief and the generation of features with low surface roughness. We have developed techniques to create large arrays of repeating micro-optical structures on polymer substrates. Here, we show our recent developments in laser structuring with the combination of half-tone and binary mask techniques.

Global interest in solar power has created a huge increase in manufacturing capability for silicon based photovoltaic devices. The consequent shortage of silicon has also led to increased interest in thin film solar technology and many new manufacturing facilities are due to come on stream. Lasers are required for precision ablation, cutting and welding tasks on both silicon and thin film based devices. The photovoltaic industry has not been slow to take advantage of the benefits and capabilities of fiber lasers for these tasks. A brief review of these processes is presented along with examples of high speed high quality silicon cutting and thin film ablation using fiber lasers.

The nanoscale growth control of functional ceramic thin films was examined by our originally developed technique, which was based on the nanoscale substrate engineering as well as atomic layer control via laser molecular beam epitaxy (laser-MBE). The atomically controlled surface of the substrate such as the ultrasmooth sapphire (single-crystal Al₂O₃) substrate with atomic steps and atomically smooth terraces was found to enhance atomically layer-by-layer growth as well as self-assembled nucleation along the atomic steps. The novel epitaxial growths could be attained on the physically or chemically controlled substrates, that is, (1) termination-regulated molecular layer-by-layer epitaxy, (2) step-decoration epitaxy resulting in the nanowire or nanodots, (3) room-temperature epitaxial growth of AlN, and (4) self-organized formation of the nanogroove-striped pattern on the film surface.

Thin films of a conducting polymer have been grown by resonant infrared matrix-assisted pulsed-laser evaporation (RIR-MAPLE). Properties of the thin films such as surface morphology and electrical conductivity have been investigated as a function of laser wavelength, fluence, and pulse structure. Using a free-electron laser whose wavelength is continuously tunable throughout the mid-infrared region (2-10 μm), we are able to deposit polymer films from various liquid matrices by resonantly exciting selective vibrational modes of the solvent. An Er:YAG laser operating at 2.94 μm is used to study the effects of different laser pulse durations. In the case of poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), it is found that only specific excitation wavelengths and pulse durations lead to the deposition of smooth and functional polymer films.

A polyamide imide and a polymeric precursor to polyimide have both been successfully transferred using resonant infrared laser ablation. Additionally a random copolymer mixture, possessing structural features common to polyimide and polyamide imide, was readily transferred using resonant infrared laser ablation. The materials are transferred with local structure intact as evidenced by Fourier transform infrared spectroscopy studies. The deposition rates of the polyimide precursor were examined at various wavelengths using a quartz crystal microbalance mounted in the deposition chamber. The effect of target type on deposition rate was also examined using two different 20 wt% polyamide imide solutions in N-methyl pyrrolidinone and dimethyl formamide and a solid pressed pellet target of polyamide imide. Both wavelength and target form were found to have a discernible effect on deposition rate. The deposited material was examined using a combination of profilometry and optical microscopy. The results show highly rough films with large, dark, string-like polymeric moieties on the surface.

Direct Write Technologies are reaching the goal of entirely printable microelectronic devices on flexible polymeric substrates. In the present work, nanoparticle inks deposited on low temperature polyimide substrates using Maskless Mesoscale Material Deposition (M3D®) technology were laser sintered using a continuous wave 1.06 micron Nd:YAG laser. In-situ measurements were made during sintering to capture the dynamic change in bulk resistivity as a function of deposited energy per volume of sintered material. It was shown that less than 0.05-μJ/μm³ started the sintering and 0.34-μJ/μm³ was enough for sintering the deposited samples regardless of initial resistance.

We describe a novel technique, called laser decal transfer, for the laser forward transfer of electronic inks that allows the non-contact direct writing of thin film-like patterns and structures on glass and plastic substrates. This technique allows the direct printing of materials such as metallic nano-inks from a donor substrate to the receiving substrate while maintaining the size and shape of the area illuminated by the laser transfer pulse. That is, the area of the donor substrate or ribbon exposed to the laser pulse releases an identical area of nano-ink material which retains its shape while it travels across the gap between the ribbon and the receiving substrate forming a deposited pattern of the same dimensions. As a result, this technique does not exhibit the limited resolution, non-uniform thickness, irregular edge features and surrounding debris associated with earlier laser forward transfer techniques. Continuous and uniform metallic lines typically 5 micrometers or less in width, and a few hundred nanometers in thickness were fabricated by laser decal transfer. These lines are of similar scale as patterns generated by lithographic techniques. Once transferred, the lines are laser-cured in-situ using a CW laser beam, becoming electrically conductive with resistivities as low as 3.4 μΩ cm. This novel laser direct-write technique is a significant improvement in terms of quality and fidelity for directwrite processes and offers great promise for electronic applications such as in the development, customization, modification, and/or repair of microelectronic circuits.

Computer calculation of optical properties of core-shell metal nanoparticles was made for some laser wavelengths. Efficiency factors of absorption, scattering and extinction by spherical core-shell gold-silver and silver-gold nanoparticles of the radiuses in the range 5-100 nm and for laser wavelengths 400, 532 and 800 nm were calculated. Analysis of influence of optical parameters of metals, radiuses of core and thicknesses of shell on optical properties of nanoparticles was made.

Theoretical investigation of the distributions of laser radiation intensities inside spherical gold nanoparticles with radiuses in the range 5-100 nm during laser irradiation for wavelengths 400, 532, 800 nm was carried out. Distributions of laser intensity are nonhomogeneous for some ranges of nanoparticle sizes and values of laser wavelengths. These results can be applied for explanation of some experimental data of laser-induced fragmentation, evaporation and formation of nanonetworks as a result of laser action on nanoparticles and for laser technologies of nanoparticles.

Eleven metals were laser-vaporized with carbon into Ar gas, and the growth of various nanocabon and composite materials were investigated. Controlling the Ar gas pressure and the metal content for Fe, Co, Ni, Cu, and Ag enabled the high yield (~70%) fabrication of single-wall carbon nanohorn particles including metal- or carbide-containing carbon nanocapsules. With the use of B, multi-wall carbon nanotubes were grown with a high yield of ~50%. For Al, Si, La, Y, and Gd, products such as carbide particles, polyhedra, and sea-urchin-type single-wall carbon nanotubes were formed. We will discuss the growth of these structures based on metal-catalyzed graphitization together with thermal graphitization.

Here we report a new method for transition-metal (TM) doped II-VI Quantum Dots (QD) fabrication and first mid-IR (2-3 μm) lasing at 77K of Cr²⁺:ZnS QD powder (~ 27 nm grain size). Cr²⁺:ZnS nanocrystalline dots (NCDs) were prepared using laser ablation. The mid-IR photoluminescence (PL) and lasing were studied. The dependence of PL spectrum profile on pump energy demonstrated a threshold behavior accompanied by the appearance of a sharp stimulated emission band around 2230 nm. The stimulated emission band is shifted to the longer wavelength with respect to the spontaneous emission and corresponds to the peak of the Cr:ZnS gain spectrum. This was also accompanied by a considerable lifetime shortening.

Thin films of permanent magnetic material are very important for different electronics applications. Permanent magnetic films are used also for micromechanical systems and for microwave integrate circuits. We present preliminary results on SmCo thin films grown on commercial plastic substrates. X-Ray Fluorescence and Magnetic Scanning measurements using GMR (Giant Magnetoresistive) sensors have been performed with the aim to study the functional magnetic properties of the thin film.

We observed the spontaneous formation of periodic nano-structures in both femtosecond laser ablation and deposition. The former involved 400-nm femtosecond pulses from a 250-KHz regenerated amplified mode-locked Ti:sapphire laser and periodic nanocracks and the nano-structure are in the form of periodic nanocracks in the substrate, the latter applied an 80-MHz mode-locked Ti:sapphire oscillator with pulse energy less than half nanojoule in a laser-induced chemical vapor deposition configuration and tungsten nanogratings grow heterogeneously on top of the substrates. These two observed periodic nanostructures have opposite orientations respecting to laser polarization: the periodic nanocracks are perpendicular to, whereas the deposited tungsten nanogratings are parallel to laser polarization direction. By translating the substrate respecting to the laser focus, both the periodic nanocrack and tungsten nanograting extend to the whole scanning range. The deposited tungsten nanogratings possess excellent uniformity on both the grating period and tooth length. Both the attributes can be tuned precisely by controlling the laser power and scanning speed. Furthermore, we discovered that the teeth of transverse tungsten nanogratings are self aligned along their axial direction during multiple scanning with appropriate offset between scans. We demonstrate the feasibility of fabricating large-area one-dimensional grating by exploiting such unique property. These distinct phenomena of nanocracks and tungsten nanogratings indicate different responsible mechanisms.

In recent years technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. So far, there are already intense light sources based on discharge or laser plasmas, light guiding and imaging optics, and detection equipment. Currently, the application of EUV radiation apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis comes more and more into focus. One objective is to make use of the strong interaction between soft x-ray radiation and matter for surface-near probing, modification or structuring techniques. In this contribution, along with first applications, we present a setup capable of generating and focusing EUV radiation, utilizing a table-top laser-induced plasma source. In order to obtain a focal spot of high EUV fluence, a modified Schwarzschild objective consisting of two spherical mirrors with Mo/Si multilayer coatings is adapted to this source. By demagnified (10x) imaging of the source an EUV spot of 30 μm diameter with an energy density of ~100 mJ/cm² is generated. We present first applications of this integrated source and optics system, demonstrating its potential for high-resolution modification and structuring of solid state surfaces. As an example, direct photo-etching of PMMA with resolution up to 130 nm will be displayed. In this context, the influence of so called "out-ofband radiation" to the etching depth of PMMA was determined by an EUV diffraction experiment. Moreover, the fragmentation of PMMA under influence of low-energy EUV radiation was investigated. For this reason the reflectivity of EUV irradiated PMMA was measured around the carbon K-edge using a table-top XUV reflectometer. This modified NEXAFS (near-edge x-ray absorption fine structure) setup in combination with FTIR (fourier transformation infrared) spectroscopy was used to identify changes in the chemical structure of the irradiated PMMA.

Flexible printed circuit board (FPCB), consisting of copper sheets laminated onto non conductive film substrates with multiple structures, are core elements in electronics with their flexibility and capability of high density 3 dimensional wiring characteristics. In laser applied FPCB processing, a better understanding of the ablation mechanism leads to precision control of the depth processing especially by monitoring of the material transition layer. For this purpose, here we investigate the temporal and spectral behavior of the plasma plum generated on the single sided structure of FPCB using the technique of laser induced breakdown spectroscopy (LIBS). Using KrF excimer laser, the characteristic spectral emission lines of C₂ swan band at the wavelength of 516.5 nm and neutral copper at the wavelength range from 510 nm to 522 nm are acquired under ambient pressure in the ablation process of polyimide film and copper coated layer respectively. From a time delay from 50 ns to 4.05 μs from the beginning of the laser pulse, the temporal profiles of the spectral intensity are obtained in steps of 200 ns, which have a tendency of exponential decrease on both C₂ and neutral copper. In particular, we concentrate our attention on the temporal intensity behavior of the Bremsstrahlung continuum emission that decides the proper set of detection time window, by which the monitoring sensitivity of LIBS is determined. Finally, using the information of the temporal analysis for each molecular, atomic, and continuum emission, the transition layer between polyimide and copper film is distinguished by their characteristic peak information.

The characteristics of femtosecond laser ablation of AlN and Al₂O₃ for precision microfabrication are studied experimentally. Specifically, the process characteristics during femtosecond laser drilling of microholes with sub-100 μm diameter are investigated for varying laser parameters and beam path designs for trepanning. The accumulation of sub-micrometer size particles within the hole is prevented using a blower and vent system. Through process optimization the microdrilling with good hole quality is achieved.

Sub-wavelength 3D- respectively 2D-structuring of borosilicate glass and polymer foil was performed using a special femtoTrain device (High Q Laser) emitting in the infrared at the intrinsic wavelength of 1028nm and also in the green at 514nm by means of SHG. The pulse duration is typically 200fs, whereas the applied low pulse energy in the nJ-range and the pulse repetition rate fixed at 20MHz. The samples were moved in three dimensions above the static laser beam by using a micromanipulator system to obtain groove-shaped structures in the surface and cylindrical bulk structures growing from the surface into the volume of the probes. The laser beam was focused using an oil immersion objective with a numerical aperture of 1.3. The diameters of 3D bulk structures are e.g. 7μm with an aspect ratio of 24:1. The widths of the surface-structures are smaller than the wavelength. The walls of the surface-structures are periodically superimposed by low scale ripples whose period length is about 20% of the laser wavelength or absolutely scaled in the sub-200nm range. The described laser setup can be considered as a novel tool for nanoprocessing in material science, nanobiotechnology, nanomedicine as well as security.

Lens heating due to absorbed UV laser radiation can diminish the achievable spatial resolution of the lithographic process in semiconductor wafer steppers. At the Laser- Laboratorium Göttingen a measurement system for quantitative registration of this thermal lens effect was developed. It is based upon a strongly improved Hartmann-Shack wavefront sensor with extreme sensitivity, accomplishing precise online monitoring of wavefront deformations of a collimated test laser beam transmitted through the laser-irradiated site of a sample. Caused by the temperature-dependent refractive index as well as thermal expansion, the formerly plane wavefront of the test laser is distorted to form a rotationally symmetric valley, being equivalent to a convex lens. The observed wavefront distortion is a quantitative measure of the absorption losses in the sample. Thermal theory affords absolute calibration of absorption coefficients.

An optical data destruction system using a high power laser beam is introduced. The system exposes data marks on optical media to a focused high power line beam. The exposure changes the physical and optical properties of the data marks and surrounding layers, making retrieval of the data impossible. Maintaining the focused laser beam on a data layer is achieved by a focus servo using a diffractive optical element (DOE). The system performance is evaluated from a number of destruction experiments on CD-Recordable (CD-R) and CD-ReWritable (CD-RW).

Scanning probe microscopy (SPM) is a high spatial resolution method of surface topography visualization and measurement of its local properties. The detecting of interaction arising between the sharp solid-state probe and the sample surface is the foundation of SPM. In dependence from nature of this interaction the scanning tunnel microscopy (STM), scanning force microscopy (SFM), scanning near field optical microscopy (SNOM), etc. are distinguished. The spatial resolution of all types of probe microscopy determins both sharpness of increasing of interaction between a probe and a sample at their approach, and shape and size of a top of a solid-state probe. So, the progress in SPM information capabilities is highly depends from probe properties and first of all from properly fabricated aperture size. Fabrication procedures are rather complicated because of nanometric scale size of aperture and hard requirements to reproducibility and need to be improved. The way how to do it is involving of feed-back in a processing procedure-results in two types of feedback for the process of drawing-out has been suggested, tested and installed into the technological set-up. Different probes have been fabricated by laser-assisted drawing-out during this work: SNOM types from optical fibers, micropipettes from quartz glass capillaries, micropipettes with microwires inside and with metallic covers outside. Some examples of application of above mentioned combined probes for cell membrane technology are described. Most important from them are topographical studying of cells and bacteria in living condition (in liquid) and studying of the mechanical properties of cell (rigidity of cell membrane) using the nanopipette as a tip of a force sensor. Also measurement of ion current that runs through cell membrane during its metabolic process using the nanopipette as well as in the well-known patch-clamp method have been done.