Investigation of operational parameters on copper bromide laser output power

In this work, a copper bromide laser with an active medium length of 58 cm and an inner diameter of 20 mm designed and constructed. He and Ne used as buffer gases. The effect of reservoir temperature, He and Ne buffer gas pressure, frequency and electrical input power on the output power investigated. The result of experiments shows that an optimum laser efficiency obtained at the electrical input power of 2.1kW and corresponding operational temperature of 510 oC. The maximum output powers, 4 and 6 W, with use of He and Ne buffer gases, were determined at pressures 11 and 24 torr, respectively.

Underwater Laser Treatment of PET: Effect of Processing Parameters on Surface Morphology and Chemistry

Rapid development of nanotechnology in processes of metal nanoparticle immobilization on solid surfaces, especially polymeric ones, requires the study of particular issues within these complex approaches. Numerous studies have been published on laser light mediated manipulation with single metal nanoparticles in water environment and even laser assisted immobilization of such particles on polymeric substrate, however, not much has been reported on fundamentals of underwater laser processing of polymer itself, especially regarding to resulting surface morphology and chemistry. In this work, we study surface morphology (atomic force microscopy (AFM)) and chemistry (angle-resolved X-ray photoelectron spectroscopy (ARXPS) and inductively coupled plasma-mass spectroscopy (ICP-MS)) of polyethylene terephthalate (PET) after underwater laser treatment in broad scale of applied laser fluencies and operating voltages. Due to typical dependence of laser efficiency on operating voltage, induced nanostructures on PET exhibited a noticeable symmetry spread out around the maxima of laser efficiency for low laser fluencies. The study of surface chemistry revealed that at high laser fluencies, photochemical decomposition of macromolecular polymer structure took place, resulting in rapid material ablation and in balanced chemical composition of the surface throughout the studied profile. Enrichment of the water bath by the low-molecular polymer degradation products proves that ablation mechanism is the governing process of surface nanostructure formation in underwater laser processing.