Dual corona discharge(DCD) transversely excited at atmospheric pressure(TEA) $CO_2$ laser system, consisted of a surface corona discharge(SCD) and a multiple-wire corona discharge(MWCD), is designed and fabricated to overcome a geometrical shortcomming of MWCD TEA $CO_2$ laser. Its output power charateristics and operation stability are markedly improved found by comparing with those of SCD and MWCD system.
Amplification of $CO_2$ laser power is carried out for far-infrared laser generation. The optimum time delay between amplifier and oscillator is determined experimentally and compared with that obtained by numerical calculation of 5-coupled rate equations. The maximum amplified output energy is 1.5J using 2-pass,2-stage amplification for 330mJ input laser energy.
Kinetics of near-resonant energy transfer in polyatomic mixture are fully elucidated by absorption experiment and theoritical calculation of rate equations. The transmittance of $CO_2$ laser beam to the mixtures which is consisted of $SF_6$ as absorber and $NH_3$,$CH_3F$,$CF_4$,Ar,He, and $N_2$ as buffer gases in measured. Vibrational-vibrational relaxation rate between $SF_6$ and polyatomic buffer gases is determined by theoritical best fitting of experimental results and this results are in good agreement with quantum mechanical collision theory.
Multiphoton absorption characteristics of freon gases, such as $CCl_2F_2$,$CHCl_2F_2$,$CBrF_3$,and $C_2Cl_2F_4$, are experimentally observed in high pressure region for $CO_2$ laser lines. $CBrF_3$ is explicitly showing the pressure dependent nonlinear absorption behavior for $Co_2$ laser 9P(10) and 9R(8) line.
Self-focusing and defocusing of TEA $CO_2$ laser pulse in $CH_3F$ media are investigated. The nonlinear refractive index coefficients are determined by the far field beam distortion method. Self-focusing of $CO_2$ laser 9P(18) line in $CH_3F$ is newly observed and this result is due to absorption in isotope effect of $C^{13}H_3F$.
Superradiant/ASE $NH_3$ laser pumped by TEA $CO_2$ laser is experimented and its dynamical behavior is studied by numerical calculation of rate equations. Output energy of $NH_3$ laser is 20mJ when pumped by $CO_2$ laser 130mJ and efficiency of this case is 16%. The output energy of $NH_3$ laser is improved by using buffer gas of $SF_6$. In this case, enhanced maximum output energy is 35mJ and efficiency is 25%.
