Characteristics of a transverse-flow CO laser excited by RF-Discharge

<title>Ridge-waveguide type microwave-pumped system versatile to both CO<formula><inf><roman>2</roman></inf></formula> and CO lasers</title>

“…For a fast-axial flow system the effective pumping rate lie is given by fle = [1 +(V/Vm)] (n:the pumping rate for slow-flow system, Vm: the mean thermal velocity based on the Maxwellian velocity distribution), so that the population density n2 of the upper vibrational level 2 is expressed for the FAF CO2 laser:1' 2 fle flco 1co [i + (V/Vm ) I ' (3) where co1 S the population density of CO2 molecule in the ground state (0 O 0). On the other hand, the overall population density of CO molecule at the vibrational level ii is expressed for the FAF CO laser:'2 7; B n exp(-Kene) nco exp(-K,n, )[i + (u/vm)],jv , (4) where B is the proportional constant, n and n0 are, respectively, the electron density and the CO molecule density, K and K0 are the reduction and deactivation coefficients of the electron and CO molecule densities, and rj, is the effective excitation efficiency which is approximated with three different functions, depending on the range of vibrational quantum number v' Moreover, 1e is related to the discharge current 'dis by n. 'dis /e t EA (e : the electron charge, iL : the electron mobility, E and A : the electric field and the mode cross-section). Thus, the population density can be expressed as a function of v' and IdSfor both the lasers.…”