Project: Adaptation of beam shaping optics for industrial tasks of femtosecond laser micromachining and medical laser diagnostics.

Lasers are widely applied in various applications in industry and medical instrumentation, their effective using is very important. Typically the spatial intensity profile of laser sources is described by Gaussian function provided by physics of creating the laser radiation. From one side, this Gaussian profile provides high energy concentration, however, from another side for many applications it is not an optimum one because of non-uniform intensity distribution within the laser beam in target plane. _x000D_In many industrial femtosecond laser micromachining applications like precise drilling, cutting, dicing, ablation, surface micro structuring, as well as in medical laser diagnostic instruments a homogenized laser beam is most preferable from the point of view of saving the energy and providing the same conditions of material treatment in the beam area. Therefore, the task of re-distribution of energy within the laser beam to provide uniform intensity profile is an actual industrial task; very often it is called as beam shaping._x000D__x000D_Femtosecond laser micromachining has become increasingly important in recent years for many fields, including telecommunications, optics, electronics, biomaterials, medicine, and transport. Fs laser ablation, because of its non-contact nature, allows the micromachining and surface patterning of materials with minimal mechanical and thermal deformation. It is now well known that for many of these applications, the femtosecond regime offers advantages over the nanosecond and picosecond regime. These advantages are in its ability to deposit energy into a material in a very short time period, before thermal diffusion can occur. As a result, the heat-affected zone, where melting and solidification can occur, is significantly reduced. Smaller feature sizes, greater spatial resolution, and better aspect ratios can hence be achieved. Altechna is currently participating in national project where the CO objective is to gain experience in femtosecond laser micromachining using amplified high repetition rate pulses and to increase ablation rate about 10 –100 times. _x000D_The quality and precision of measurements carried out by laser medical instruments of analyzing the human blood, for example the instruments from Horiba ABX, are in strong dependence on uniformity and stability of a laser radiation applied to a sample under measurement. Applying of usual lasers with Gaussian beams doesn't provide a required performance, therefore providing uniform laser beam is crucial for such instruments. Another innovative biomedical application for uniformly distributed femtosecond laser radiation appears in the field of two-photon induced fluorescence diagnostics, where the intensity of the fluorescence signal from an endogenous or exogenous agent and the margins of the excited area in biological tissue depend on the square of beam intensity. Due to the relatively narrow range of the beam intensities applicable in biological systems for two-photon excitation, the control over the intensity distribution pattern of the beam plays essential role ensuring safety and accuracy of such diagnostic procedures. _x000D_Project P Moltech was chosen as it has great experience in designing tools converting Gaussian laser beam into a collimated flattop (or top-hat) beam with nearly 100% efficiency. The method of field mapping used in achromatic refractive beam shaping optics from MolTech GmbH offers advantages among other beam shaping techniques for the technologies planned to be improved in frames of this project._x000D__x000D_Altechna has developed femtosecond laser micromachining system allowing to fabricate complicated structure objects with submicron resolution in high speed, this system is considered as a base for start investigations. _x000D_As a next step it is planned to supply the system with beam shaping optics provided by MolTech GmbH and to carry out applied researches to define optimum beam profiles and other parameters of technological processes for tasks of micromachining. _x000D_As a result of this investigation work there should be defined ways of modification of the Altechna system including requirements to design, parameters of laser sources (wavelength, frequency, pulse duration, power) as well as optimum parameters of technological processes._x000D__x000D_Since the technical task of beam shaping for micromachining technologies is close to the task to be solved while developing the optics for laser medical instrumentation for blood analyzing, the experience of the work with beam shaping optics will be applied to improve optical design of instruments from Horiba ABX. _x000D_It is planned to develop an improved optics for this Horiba laser instruments._x000D__x000D_Finally improved design of the femtosecond laser micromachining system, technological instructions for specific microfabrication tasks and improved optics for medical instrumentation will be realized. These developments are planned to be applied in serial products of the project participants.

Acronym MICROSHAPE (Reference Number: 4386)
Duration 01/09/2008 - 29/10/2010
Project Topic Improving of performance of industrial technologies based on femtosecond laser micromachining and laser medical instruments to analyze the human blood by applying modern techniques of laser beam shaping. Goals of the work are developing of improved machinery and medical instruments.
Network Eurostars
Call Eurostars Cut-Off 1

Project partner

Number Name Role Country
3 Altechna Co.Ltd. Coordinator Lithuania
3 MolTech GmbH Partner Germany
3 Horiba ABX Partner France