Observation of mode pulling in a CO_2 laser (original) (raw)
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Transverse mode competition in a CO_{2} laser
Physical Review A, 1996
Pattern formation resulting from transverse mode competition has been observed in CO 2 lasers with a large transverse section and a stable near-degenerate optical cavity. The pattern properties ruled by transverse hole burning are analyzed experimentally as a function of the Fresnel number, the frequency intermode spacing, and the symmetry breaking induced by the astigmatic cavity. It is shown that mode competition imposes selection rules amid modes belonging to the largest transverse mode family allowed to oscillate.
Vibrational kinetics of the active media of CW CO 2 lasers
Journal of Applied Spectroscopy, 2005
The vibrational kinetics of CW CO 2 lasers has been analyzed within the framework of a temperature model. The necessity of taking into account the coupling of the vibrational modes of the CO 2 molecule in determining the occupation numbers and the store of vibrational energy in individual modes is shown. Expressions that connect vibrational temperatures with the rates of excitation and relaxation of the lower vibrational levels of modes have been obtained. The ratios between the vibrational temperatures on selective excitation of the 00 o 1 level and on excitation of CO 2 molecules in an electric discharge as well as the character of the dependences of vibrational temperatures on the pumping-energy value are discussed.
Frequency match of the Nd:YAG laser at 1064 µm with a line in CO_2
Applied Optics, 1992
We report on the measurement of a frequency match between the oscillation frequency of the Nd:YAG laser at 1.064 μm and a line in the vibration-rotation spectrum of the CO 2 molecule. The line occurs near the center of the Nd:YAG gain profile and is inferred to be narrow from a knowledge of the CO 2 molecular structure. The significance of the frequency match lies in its application as a reference for absolute-frequency stabilization of the Nd:YAG laser.
FM mode-locked high-pressure CW RF-excited CO2 waveguide laser
… , IEEE Journal of, 1991
We report the results from a study of a FM modelocked CW RF-excited COz waveguide laser operated at 0.25-2 atm gas pressures. The experimental pulses of a few hundred ps FWHM are considerably shorter than previously reported for CW mode-locked CO, lasers. The experimental results are compared with the results of numerical calculations using a frequency domain simulation model.
IEEE Journal of Quantum Electronics, 1980
We have developed an accurate method of determining vibrational temperatures and populations in C 0 2 laser discharges. Our technique involves the use of both the regular 00'1 and sequence 00'2 laser transitions as probes of a C02 laser amplifier. We have been able to separately investigate the quantitative effects of gas heating, dissociation, and vg mode excitation efficiency on the small-signal gain in typical CW C 0 2 lasers. In general we find that the maximum gain attained in a typical flowing gas CW C02 laser is limited by dissociation of C 0 2 at high discharge currents.
Nonlinear interaction of transverse modes in a CO_{2} laser
Physical Review A, 1994
We show the possibility of achieving experimentally a Takens-Bogdanov bifurcation for the nonlinear interaction of two transverse modes (l = ±1) in a CO 2 laser. The system has a basic O(2) symmetry which is perturbed by some symmetrybreaking effects that still preserve the Z 2 symmetry. The pattern dynamics near this codimension two bifurcation under such symmetries is described. This dynamics changes drastically when the laser properties are modified.
Continuous-Wave Laser Action on Vibrational-Rotational Transitions of CO2
Physical Review
We have obtained cw laser action on a number of rotational transitions of the Z"+-Zg+ vibrational band of CO2 around 10.4 and 9.4p. The laser wavelengths are identified as the P-branch rotational transitions from P(12) to P(38) for the 00'1-10'0 band and from P(22) to P(34) for the 00'1-02'0 band. Strongest laser transition occurs at 10.6324' {vacuum). A cw power output of about 1 mW has been measured. All these laser transitions can also be made to oscillate under pulsed discharge conditions with a small increase in the peak laser power output. No E-branch transitions have been seen to oscillate either under cw or pulsed discharge conditions. The wavelength measurements are in reasonable agreement with earlier measurement of the bands in absorption, but there are slight differences. These are ascribed to possible pressure-dependent frequency shift eBects. A study has been made of the time dependence of the laser output under pulsed excitation, and some conclusions about possible excitation processes are given. Theoretical interpretation given earlier for laser action on vibrational-rotational transitions is discussed in a generalized form. The theory is applicable to both the linear polyatomic molecules and the diatomic molecules.
Systematic experimental study of instabilities in the sealed CO2 laser
Czechoslovak Journal of Physics, 1981
A systematic pressure-current experimental study of the wave instability regions in glow--discharge of different CO 2 laser mixtures has been accomplished. The forward ionization wave F-has been found tobe the main instability. At low eurrents (<30 mA)and higher pressures (~> 550 Pa) the laser discharge beeomes stable. The highest output power ata given mixture ratio was achieved in these quiet regions. The normalized electric field dependences of wavenumber, phase and group veloeities of the F-wave are presented.