New infrared laser lines in argon, krypton, and xenon

Fourteen new infrared laser transitions in Ar, Kr, and Xe ranging from3.725 to 17.233 mum are reported. All of the Kr laser transitions and all but one of the Ar and Xe transitions have upper levels in thesordstate: the majority of the transitions satisfy the conditionDelta K = Delta J. Identification of a previously observed, unidentified laser line at 5.804 μm in Ar is given.     

Third-harmonic generation in argon, krypton, and xenon: Bandwidth limitations in the vicinity of Lyman-α

Using experimentally determined oscillator strengths and photoionization cross-sectional data, we compute the dispersion characteristics of Ar, Kr, and Xe up to their first ionization levels and determine the spectral regions in the VUV where these gases exhibit negative dispersion and so can be efficiently used for frequency tripling. We then investigate the bandwidths over which efficient tripling can be achieved in phase-matched gas mixtures. The bandwidth is limited by the rapidly varying dispersion in the vicinity of resonance transitions in the gases. In particular, we look at the case of frequency tripling 3647 Å radiation to 1215.7 Å (hydrogen Lyman-α) and show, that for fundamental wavelength bandwidths as narrow as 1 Å, the rapid change in refractive index with wavelength can preclude phase matching over the entire bandwidth of the radiation.     

New UV and visible laser oscillations in chlorine, oxygen, nitrogen, and titanium

Eight new UV laser lines and 12 new visible laser lines of chlorine, oxygen, nitrogen, and titanium have been obtained by connecting or not connecting inductance coils with the discharge circuit to control the peak discharge current so as to stimulate the laser actions of the lower multiple ion or the higher multiple ion. As the laser duration is much longer than the discharge duration, the lasers are excited in the afterglow, that is, these are recombination lasers in the UV and the visible regions.     

Violet laser oscillations in a krypton ion laser

The violet output power over 500mW obtained from a krypton ion laser and successfully applied to detect cancer is reported.     

Comparison of the output spectra of krypton and xenon filled flashtubes

The spectral output of krypton filled flashtubes has been investigated and compared to that of xenon filled tubes. It was observed that although xenon has a higher luminous efficiency than krypton, the krypton output is 150 to 200 percent of the xenon output at 810 nanometers depending on the input energy level. The implication is that krypton is a more efficient pumping source for lasers with an absorption band in the region of 810 nanometers.     

Comparison of the performance of krypton and xenon filled flashtubes for pumping Nd3+doped YAG lasers

It has been shown experimentally that xenon filled flashtubes are more efficient for pumping Nd³⁺doped YAG lasers than krypton flashtubes in spite of the higher output of the krypton flashtube at 0.810 microns.     

Electron energy spectra in neon, xenon, and helium-neon laser discharges

Absolute measurements of the electron energy spectrum in a helium-neon mixture and in pure neon and xenon have been obtained by an energy analysis of a sample of electrons extracted through a small hole in the anode. The spectrum appears to be nearly Maxwellian for the lower pressures but deviates markedly from a Maxwellian at higher pressures. At higher pressures, the energetic part of the spectrum drops off faster, and one can describe this part by a Maxwellian of lower temperature than that for the bulk of the distribution. The average energies agree with those obtained from microwave measurements of the radiation temperature of the electrons if corrections are made for nonthermal distribution. Several production rates are computed with the help of the measured spectra, and they are related to the wall current, the power dissipation, and the possible electron depopulation of helium metastables. The production and destruction rates for the different parts of the energy spectrum have been formulated mathematically. A theoretical formula, which describes the actual spectra, has been derived for the faster part of the spectrum. For the helium-neon laser discharge we can say definitely that the de-excitation of helium metastables by electrons is negligible.     

Characteristics and performance of high-power CW krypton arc lamps for Nd:YAG laser pumping

Experimental results are presented on the performance of CW krypton arc lamps operated at power levels up to 20 kW. These lamps are suitable for pumping of high-powered Nd:YAG lasers. Operating life and electrical and spectral characteristics of the lamps were tested as a function of arc length, bore size, and fill pressure.     

Forced and self-mode-locking of the krypton ion laser

Mode-locking of a krypton ion laser has been studied using a graphite-bore plasma tube and acoustooptic modulator In forced mode locking, 0.2-ns pulses were achieved with the principal laser lines. In contrast with the argon laser, there is a marked tendency for self-locking in krypton.     

Line competition in the neutral argon laser

Uncertainties in transition assignments for the neutral argon laser lines at 1.792 and 2.208 μm have been resolved by operation of a CW neutral argon laser with several simultaneous output wavelengths. The observed competition effects have established the correct transition for the 1.792-μm line to be3d(1/2)_{1}deg -4p(3/2)_{2}and for the 2.208-μm line to be3d(1/2)_{1}deg -4p'(3/2)_{2}.     

Observation of CW laser action in chlorine, argon, and helium gas mixtures

CW oscillation on several lines from 1.9 to 3.1μ has been attained in mixtures of Cl, He, and A. Power outputs up to 65 mW have been observed at 2.45μ in a 187-cm-long by 2.5-cm-diameter laser. Evidence of energy transfer between A and Cl has also been observed.     

Frequency stabilization and noise suppression in the argon FM laser

We describe 1:10⁸active frequency stabilization, 20-to 30-dB suppression of low-frequency noise, and suppression of axial-mode beats to 1100 MHz in an argon FNI laser at 5145 Å.