Search Results
Scalable, high power line focus diode laser for crystallizing of silicon thin films
2010, Lichtenstein, N., Baettig, R., Brunner, R., Müller, J., Valk, B., Gawlik, A., Bergmann, J., Falk, F.
We present the design and performance of a diode laser module producing a high intensity line focus at 808 nm for material processing. The design is based on a linear array of 7 laser bars and beam forming optics featuring a micro-optic homogenizer. The module delivers a total output power of 900 W at 140 A and peak intensity created in the focus area of 10.3 kW/cm2. Two systems with line length of 5 cm and 10 cm at a large working distance of 110 mm have been realized. The chosen concept allows scaling in length by joining multiple modules which is of interest for material processing in industrial applications. Application results from laser crystallization of amorphous silicon seed layers used in the fabrication of photovoltaic cells for solar panels are given.
Optimization of the energy deposition in glasses with temporally-shaped femtosecond laser pulses
2011, Mauclair, C., Mishchik, K., Mermillod-Blondin, A., Rosenfeld, A., Hertel, I.V., Audouard, E., Stoian, R.
Bulk machining of glasses with femtosecond laser pulses enables the fabrication of embedded optical functions. Due to the nonlinear character of the laser-matter interaction, structural modifications can occur within the focal region. To reach a full control of the process, ways of controlling the deposition of the laser energy inside the material have to be unveiled. From static and time-resolved pictures of bulk-excitation of a-SiO2 and borosilicate glass, we show that particular laser temporal shapes such as picosecond sequences can better confine the energy deposition than the femtosecond sequence by reducing the propagation artifacts.
Properties of ns-laser processed polydimethylsiloxane (PDMS)
2016, Atanasov, P.A., Stankova, N.E., Nedyalkov, N.N., Stoyanchov, T.R., Nikov, R.G., Fukata, N., Gerlach, J.W., Hirsch, D., Rauschenbach, B.
The medical-grade polydimethylsiloxane (PDMS) elastomer is a widely used biomaterial in medicine and for preparation of high-tech devices because of its remarkable properties. In this work, we present the experimental results on drilling holes on the PDMS surface by using ultraviolet, visible or near-infrared ns-laser pulses and on studying the changes of the chemical composition and structure inside the processed areas. The material in the zone of the holes is studied by XRD, ?-Raman analyses and 3D laser microscopy in order to obtain information on the influence of different processing laser parameters, as wavelength, fluence and number of consecutive pulses on the material transformation and its modification.