On the excitation mechanism of the CW atomic fluorine laser

A plasma mixing device in which a helium plasma beam is crossed with a molecular fluorine beam was used to operate an atomic fluorine laser. Operation conditions confirm that excitation occurs through collisions of helium metastables and F₂ molecules. Collisions with other F-donors, such as NF₃, CF₄, C₂ F₆, and SF₆, do not yield F-atoms in one of the possible upper laser levels. In lasers using such F-donors, excitation has to occur through electron collisions with F-atoms which have been generated in a preceding process     

CW submillimeter laser action in ethyl chloride

We present ten new far-infrared (FIR) laser lines obtained by optically pumping ethyl chloride by means of a CW waveguide CO₂ laser with a tunability range of 300 MHz. By means of a heterodyne technique and using, as mixing element, a metal-insulator-metal (MIM) point contact diode or a new home built metal-semiconductor diode, we measured the frequency of all these new lines, as well as that of another line, previously reported in literature. With our new lines, the total number of FIR laser lines emitted by ethyl chloride rises to 14; for each of them we give the offset relative to the center frequency of the pumping radiation, the polarization relative to that of the pumping CO₂ laser, the relative intensity, and the optimum operation pressure. Seven of the new lines have frequencies in the 300-512-GHz range and four of them are strong enough to be used in high-field EPR spectroscopy     

Experimental investigation of the atomic fluorine laser

The atomic fluorine laser, as produced by a fast pulsed discharge in He-NF3mixtures, is investigated experimentally. Total collisional quenching rates of He 2³S on NF3, BF3, CBrF3, CCIF3, CHF3, CF4, C2F6, CO2, SF6, and N2are reported. Upper limits for collisional quenching rates of He 2¹S, 2³P, and 2¹P atoms on NF3are determined. We conclude that energy transfer from excited neutral He to NF3is not the primary pumping mechanism in the He-NF3atomic fluorine laser.     

CW atomic oxygen laser at 4.56 µ

CW laser oscillation at 4.56 μ was observed in atomic oxygen produced in a magnetic induction discharge located at the upstream end of a fast flow system. The laser transition has been identified and an inversion scheme is proposed.     

New CW FIR laser action in optically pumped vinyl chloride

Thirty-four new FIR lasing lines are reported in vinyl chloride optically pumped by a CO2laser. Ten of them are observed when using pump lines belonging to the 10.8 μm hot band.     

Frequency tuning of a CW atomic iodine laser via the Zeeman effect

A continuously operating, C₃F₇I photolytic 1.315-μm atomic iodine laser has been used to make the first precise observations of frequency tuning of an atomic iodine laser by means of the Zeeman effect. Application of a uniform magnetic field to the gain region of the photolytic iodine laser causes the laser to operate at different frequencies as a function of the strength of the applied field and the polarization of the laser. With the light polarized perpendicular to the applied magnetic field by means of Brewster output windows, the laser could be tuned to frequencies near the 3-4, 2-2, and 3-3 zero-field transitions of the hyperfine spectrum of atomic iodine. With the light polarized parallel to the applied magnetic field the laser could be tuned to two frequencies bracketing the 3-4 zero-field transition and one frequency near the 2-2 transition. Measurements show close agreement between the observed frequency behavior and theoretical models     

CW laser pumped emerald laser

A CW laser pumped emerald laser is reported, A 34 percent output power slope efficiency is observed with longitudinal pumping by a krypton laser in a nearly concentric cavity. The laser has been tuned from 728.8 to 809.0 nm, Losses in emerald are larger than those of alexandrite determined in a similar cavity. Our data also indicate that the excited state absorption minimum is shifted from that of alexandrite.     

A kinematic model for the oligo-mode action of a CW dye laser

Several stable oligo-mode spectra of a CW dye laser were recorded with the aid of an optical spectrum analyzer (scannable Fabry-Perot) giving Fourier transforms of the light field. Simultaneously the total intensity was measured with a fast photodiode and analyzed for beat signals with an RF spectrum analyzer. The spectra observed can be explained consistently in terms of a kinematic model postulating that competing modes cannot exist simultaneously and therefore show a "spiking" behavior. The repetition frequency of the spiking was found to be the frequency difference of the competing modes, a mechanism known from mode-locking. For the spectra observed experimentally, analytic expressions for the time development of the field amplitudes are given which are in good agreement with the experimental results.     

Submillimeter laser action of CW optically pumped CF3Br

Far infrared laser action at 823 and 883 μm is reported for the first time from the optically pumped CF3Br molecule. This molecule exhibits strong absorptions in thePandRbranches of the 9 μm band of the CW CO2laser. Tentative assignments are proposed for the first two transitions observed.     

Long operating time CW atomic iodine probe laser at 1.315 µm

A photolytically pumped longitudinal flow CW atomic iodine laser at1.315 mum with virtually an unlimited operating time and easy operation is reported. Several weeks of continual operation is easily attainable. The prolonged lasing is achieved by employing a passive closed cycle flow system of the C3F7I laser fuel. A high pressure dc Hg arc lamp is used for the photolytic pumping. Peak CW powers of 38 mW have been obtained along with good stability (∼1 percent amplitude fluctuations) in the fundamental TEM00mode via the use of an internal lens.     

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.     

CW ultraviolet and visible laser action from ionized silver in anelectron beam generated plasma

Continuous wave laser oscillation was obtained in the 318.1-nm and the 478.8-nm lines of Ag(II) in a neon-silver vapor mixture excited by glow discharge electron beams. Laser output powers of 14 and 60 mW were obtained in the ultraviolet and blue transitions, respectively, using nonoptimized optical cavities. The use of neon as a buffer gas significantly increases the number of possible laser lines that might be obtained with this type of excitation by means of selective energy transfer processes involving quasi-resonant collisions     

Tunable CW alexandrite laser

Wavelength-tunable CW laser action has been obtained from solid-state alexandrite, BeAl2O4:Cr³⁺. Laser emission occurred between 744 and 788 nm with a maximum of 6.5 W observed at the 765 nm wavelength with 3 kW of mercury arc excitation.     

Gain in CW laser pumped FIR laser gases

This study is an investigation of the FIR radiation amplification in CW laser excited gases so essential for a complete quantitative understanding of the FIR laser cycle. The small-signal FIR gain coefficients have been measured as functions of the relevant parameters for two transitions in CH3OH and three in CH2F2. The measurements, demonstrating the influence of coherent pumping have been compared to quantum-mechanical calculations of a three-level system, interacting resonantly with two coherent fields. The good agreement found between theory and measurements indicates the correctness of the theory in predicting the gain properties of the CW FIR lasers. Also FIR gain saturations have been measured directly and exhibit the expected features.     

Dispersion-induced instability in CW laser oscillators

A CW-pumped laser with a short photon cavity lifetime may show an unstable output in the form of spontaneous pulsations or noise. In this paper, a model is developed which reconciles previous studies of unstable behavior in homogeneously and inhomogeneously broadened lasers. Specific regions of instability are predicted for xenon lasers, and it is concluded that some degree of inhomogeneous broadening makes the instability much more likely to be observed.     

High-efficiency tunable CW dye laser

An output power of 1 W is reported from a tunable CW dye laser pumped by 3.5 W of argon laser radiation. The nearly 30 percent conversion efficiency is achieved by using a very low-loss folded 3-mirror cavity and by pumping through a Brewster-angle dispersing prism.     

连续的DCN波导激光器

本文介绍了连续DCN波导激光器。激光管由直径4.8厘米、长2.5米的石英管组成,其输出波长为195微米和190微米,最大输出功率为30毫瓦左右。同时给出实验研究结果以及输出功率与其他参数之间的关系。     

A CW external-cavity surface-emitting laser

Room temperature, continuous wave (CW) operation of an external-cavity, optically-pumped surface-emitting laser is reported. The device is a resonant-periodic gain (RPG) vertical-cavity surface-emitting laser (VCSEL) with the top mirror stack replaced by an epitaxially grown antireflection (AR) coating. An external mirror having a 50-mm radius of curvature completes the resonator in a near hemispherical configuration. Mode spectra, input-output curves, and polarization properties of the device are presented.