Investigation of Copper Vapor Pulsed Laser with Industrial Active Elements of “Kulon” Series using One Convex Mirror Mode and Its Capabilities for Technological Applications

• Main Author: N. A. Lyabin
• Format: Article
• Language: Russian
• Published: MGTU im. N.È. Baumana 2014-01-01
• Series: Nauka i Obrazovanie
• Subjects: copper vapor lasers; radiation divergence; peak power density; microprocessing of materials
• Online Access: http://technomag.edu.ru/jour/article/view/617

<p>Within the scope of the given paper spatial, time and energy characteristics of a copper vapor laser (CVL|) have been investigated in the mode of one convex mirror using the most powerful industrial sealed-off active elements (AE) of “Kulon” series: 15 W GL-206D model and 20 W GL-206I model in order to define the capabilities of using its one-beam radiation for effective microprocessing of materials.</p><p>The carried out calculations and experimental investigations showed that one can vary the radiation beam divergence within a wide range by changing the radius of curvature of CVL convex mirror; and one can reach values close to diffraction limit at radii of curvature one-two orders lower than the distance from the mirror to AE output aperture. At small radii of mirror curvature (R = 6-30 mm) the CVL output radiation beam divergence can only 2-3 times (0.15- 0.35 mrad) differ from diffraction limit. At these divergences the peak power density in a focused spot can reach 109…1010 W/cm2 values.</p><p>With the increase of AE discharge channel length the CVL output radiation beam divergence in one-mirror mode decreases and tends to diffraction limit, while power increases, which in the aggregate leads to the sharp increase of peak power density. Therefore, from practical point of view the industrial AEs “Crystal” GL-205А and GL-205B with 0.93 and 1.23 m discharge channel length and 20 mm diameter are the most effective ones. Besides the formation of one high quality beam, the advantages of one-mirror mode include a high axis stability of directivity pattern of this beam and pulsed energy, which increase the quality of microprocessing of materials.</p><p>Practical experience of using CVL with one convex mirror shows that 109 W/cm2 peak power density level is sufficient only for efficient microprocessing of foiled materials and solder cutouts (0.02-0.1 мм). The use of this CVL as a driving oscillator (DO) in a copper vapor laser system (CVLS) of the type: driving oscillator – power amplifier (DO – PA) using 30-50 W industrial “Crystal” AEs in PAs allows to increase peak power density up to 1011 W/cm2 , sufficient for efficient and qualitative microprocessing of materials up to 1 mm thick.</p><p>The main conclusions on the results of CVL investigations are also true for other metals vapor pulsed lasers as well as for gas and solid-state lasers with a short period of population inversion existence.</p>