Laser copper vapor

LLNL AVLIS Laser. The first WFS measurements using a Na LGS were performed at LLNL (Max et al., 1994 Avicola et al., 1994). These experiments utilized an 1100 W dye laser, developed for atomic vapor laser isotope separation (AVLIS). The wavefront was better than 0.03 wave rms. The dye laser was pumped by 1500 W copper vapor lasers. They are not well suited as a pump for LGSs because of their 26 kHz pulse rate and 32 ns pulse length. The peak intensity at the Na layer, with an atmospheric transmission of 0.6 and a spot diameter of 2.0 m, is 25 W/cm, 4x the saturation. The laser linewidth and shape were tailored to match the D2 line. The power was varied from 7 to 1100 W on Na layer to study saturation. The spot size was measured to be 7 arcsec FWHM at 1100 W. It reduced to 4.6 arcsec after accounting for satura-... 

The condition for observing induced emission is that the population of the first singlet state Si is larger than that of So, which is far from the case at room temperature because of the Boltzmann distribution (see above). An inversion of population (i.e. NSi > Nso) is thus required. For a four-level system inversion can be achieved using optical pumping by an intense light source (flash lamps or lasers) dye lasers work in this way. Alternatively, electrical discharge in a gas (gas lasers, copper vapor lasers) can be used. 

Figure 11.44 is a schematic diagram of one LIF instrument (Stevens et al., 1994 Brune et al., 1998). An air-cooled copper-vapor laser pumps a dye laser whose output at 616 nm is doubled to generate the 308-nm exciting radiation. An OH reference cell in which OH is generated from the thermal dissociation of water... 

The use of laser-induced fluorescence (LIF) for tropospheric HO and H02 measurements was reported by Hard and co-workers (108-110), who developed a fluorescence technique based on pumping the air sample into a low-pressure cell (FAGE) and exciting it with a copper vapor laser-pumped dye laser with a high repetition rate. Their H02 measurements were not made in conjunction with enough other supporting measurements to allow an accurate test of photochemical models from the results. 

Detection of Carbon-Fluorine Bonds in Organofluorine Compounds by Raman Spectroscopy Using a Copper-Vapor Laser ... 

Figure 9. Design of the dye laser amplifier. Ultrafast laser pulses are amplified roughly 10,000 times by seven passes through a dye jet pumped by a copper vapor laser.

Copper vapor laser A pulsed source of coherent radiation emitting at 578.2 and 510.5 nm from excited copper atoms. 

Fig. 11. Schematic view of the copper vapor laser pumped dye laser system developed at Harvard for the detection of OH and HO2 radicals in situ from balloon-borne descent probes.

Sindrup SH, Brosen K, Bjerring P, Arendt-Nielsen L, Larsen U, Angelo HR, Gram LF. Codeine increases pain thresholds to copper vapor laser stimuli in extensive but not poor metabolizers of sparteine. Clin. Pharmacol. Ther. 1991 49 686-693. 

Haba et al. [28] have computed the temperature distributions induced by pulsed irradiation of Mn-Zn ferrite with a copper vapor laser (k = 511 and 578 nm) under the processing conditions of Table 18.1. This particular source is characterized by a top hat, circular intensity distribution. 

Aucfiio RQ, Rubin NV, Smith bw and wine-EOEDNEE JD (1998) Ultratracc determination of Pt in environmental and biologcal samples by electrothermal atomization laser-excited atomic fluorescence using a copper vapor laser pumped dye. J Anal Atom Spectrom 13 49-54. 

For time-resolved laser spectroscopy, pulsed dye lasers are of particular relevance due to their continuously tunable wavelength. They can be pumped by flashlamps T 1 ps to 1 ms), by other pulsed lasers, for example, by copper-vapor lasers (T 50 ns), excimer lasers T 15 ns), nitrogen lasers T = 2-10 ns), or frequency-doubled Nd YAG lasers T = 5-15 ns). Because of the short relaxation times t/, Xk — 10 s), no spiking occurs and the situation of Fig. 6.1a is realized (Vol. 1, Sect. 5.7). The dye laser pulses have durations between 1 ns to 500 ps, depending... 

A serious limitation is the low repetition rate of most pump lasers used for the amplifier chain. Although the input pulse rate of the pico- or femtosecond pulses from mode-locked lasers may be many megahertz, most solid-state lasers used for pumping only allow repetition rates below 1 kHz. Copper-vapor lasers can be operated up to 20 kHz. Recently, a multi-kilohertz Tl Al203 amplifier for high-power femtosecond pulses at X = 764 nm has been reported [734],... 

The ions can be separated from the neutrals by electric fields, which collect them into a Faraday cup. This technique has been used, for example, for the separation of atoms in the gas phase by resonant two-photon ionization with copper-vapor laser-pumped dye lasers at high repetition frequencies [1429]. Since the line density in the visible absorption spectrum of is very high, the lasers are crossed perpendicularly with a cold collimated beam of uranium atoms in order to reduce the line density and the absorption linewidth. 

P. Peuser, G. Herrmann, H. Rimke, P. Sattelberger, N. Trautmemn, W. Ruster, F. Ames, J. Bonn, H.J. Kluge, V. Kronert, E.W. Otten, Trace detection of plutonium by three-step photoionization with a laser system pumped by a copper vapor laser. Appl. Phys. B 38,249 (1985)... 

Laser ablation requires an appropriate combination of laser and ablated materials. Many lasers have been used for machining of microstructures, including CO2 lasers, solid-state lasers, copper vapor lasers, and excimer lasers. Pulsed lasers are used because of their ability to deliver high peak power. For a continuous laser, a shutter control can provide the necessary pulsation. The peak power, laser intensity, and fluence are calculated by the following equations ... 

In this way the exponential dependence of lout on L can be easily verified. Several commercially available pulsed lasers operate in the ASE mode. Examples are copper-vapor laser and the gas lasers based on HF molecules. 

Karpuhin, V. T. Malikov, M. M. Val yano, G. E. Borodina, T. I. Gololobova, O. A. Investigation of the characteristics of a colloidal solution and its solid phase obtained through ablation of zinc in water by high power radiation from a copper vapor laser . High Temp+, 2011,49(5), 681-686. 

Depending on the pumping source (either flash-lamps or other laser systems, such as excimer, Nd YAG, nitrogen, or copper vapor lasers), the repetition rate of the dye laser can be varied between 10Hz and as high as a megahertz. It is obvious that at low repetition rates only a small fraction of analyte atoms, which pass the interaction volume, is irradiated by the laser. This restricts the detection limit of the measurement, in particular if only small amounts of sample material are available, as in microanalysis. 

The short wavelength X = 337 nm of the nitrogen laser permits pumping of dyes with fluorescence spectra from the near UV up to the near infrared. The high pump power available from this laser source allows sufficient inversion, even in dyes with lower quantum efficiency [5.170-5.174]. At present the most important dye laser pumps are the excimer laser [5.175,5.176], the frequency-doubled or -tripled output of high-power Nd YAG or Nd glass lasers [5.177,5.178], or copper-vapor lasers [5.179]. 

---