Longitudinally excited CO_2 laser with tail-free short pulse

摘要

We developed a longitudinally excited CO_2 laser with a tail-free short laser pulse. In a discharge tube, two structures were researched. One is a shingle scheme that is constituted of a 45 cm-long discharge tube. Another is a tandem that is constituted of two 30 cm-long discharge tubes connected with an intermediate electrode were used. In gas media, CO_2-rich mixture (CO_2: N_2= 20: 1) was used to reduce a laser pulse tail. The laser system did not require expensive and scarce helium. A fast discharge (＜1 μs) in a low gas pressure (＜1.8 kPa) produced a tail-free laser pulse with the pulse width of about 100 ns. The single scheme produced an output energy of 4.7 mJ by a charging voltage of -36.3 kV, and the tandem scheme produced an output energy of 9.3 mJ by a charging voltage of -25.2 kV. The tandem scheme produced higher spike pulse by lower voltage than the single scheme. Therefore, the tandem scheme will be effective in longitudinally excited CO_2 lasers with simple and compact designs.