Argon-ion lasers

Table 7.40 Principal Argon-Ion Laser Plasma Lines 7.88...

With continuous lasers (for example an argon ion laser), the energy delivered is usually much less than from pulsed ones, and the focusing is not so acute. Thus, the irradiated area of the sample is more like 10 cm rather than 10" cm, and the energy input is much less, about 100 kW/cm rather than the 100,000 kW/cm described earlier. 

Figure 5.17 shows the rotational Raman spectrum of N2 obtained with 476.5 nm radiation from an argon ion laser. From this spectrum a very accurate value for Bq of 1.857 672 0.000 027 cm has been obtained from which a value for the bond length tq of 1.099 985 0.000 010 A results. Such accuracy is typical of high-resolution rotational Raman spectroscopy. 

A further advantage, compared with the alexandrite laser, apart from a wider tuning range, is that it can operate in the CW as well as in the pulsed mode. In the CW mode the Ti -sapphire laser may be pumped by a CW argon ion laser (see Section 9.2.6) and is capable of producing an output power of 5 W. In the pulsed mode pumping is usually achieved by a pulsed Nd YAG laser (see Section 9.2.3) and a pulse energy of 100 mJ may be achieved. 

CW dye lasers are usually pumped wifh an argon ion laser, up to abouf f W of continuous dye laser power being produced, compared wifh abouf f MW peak power which may be produced in a pulsed dye laser. 

Argonaut Argon difluoride Argon fluoride Argon-helium Argon ion lasers Argon-oxygen... 

An argon-ion laser is used in some laser light shows. The argon ion has strong emissions at 485 nm and 512 nm. 

In the continuous wave (CW) experimental setup a sample is constantly illuminated by a probe beam and the steady state change in the transmission is detected (see Fig. 7-1). An argon ion laser has been used to generate the pump beam and the probe beam was from an incandescent lamp (tungsten or others), producing a broad spectrum (0.5 to 5 pm) [6]. Both pump and probe beams are directed onto the sample film and the transmitted probe light is collected, filtered through a monochromator, and detected by a photodetector. Both the pump and the probe... 

Figure 15-7. (a) Pholoinduccd IR absorption spectra of P30T and P30T/Q, (5%) at 80 K obtained by pumping with an Argon ion laser at 2.41 eV (reproduced by permission of the American Physical Society from Rel. [32)). 

Figure 15-20. Currenl versus voltage characteristics of the lTO/MEH-PPV/C Au device in the dark (diamonds) and upon illumination wilh the 514.5 nm line of argon-ion laser of 1 mW/cm2 (triangles) (reproduced by permission of the American Institute of Physics from Ref. 1891).

Figure 15-9. (a) IJglil-induccd electron spin resonance spectra of MDMO-PPV/PCBM upon successive illumination with 2.41 eV argon ion laser, (b) Integrated LESR intensity [ESR (illuminatcd)-ESR (dark)] of MDMO-PPV/PCBM (reproduced after Ref. 1401). 

In addition to these lowtemperature thermal processes, aluminum can be deposited by the decomposition of an alkyl precursor with a UV laser, or with an argon-ion laser in applications such as patterns and... 

UV-Vis spectroscopy may also provide valuable information if small molecules are studied. However, the photochemical sensitivity of many sulfur-containing molecules may trigger changes in the composition of the sample during irradiation. For instance, this phenomenon has been observed in Raman spectroscopy using the blue or green hnes of an argon ion laser which sometimes decompose sensitive sulfur samples with formation of Sg [2, 3]. Reliable spectra are obtained with the red hnes of a krypton ion or a He-Ne laser as well as with the infrared photons of a Nd YAG laser. 

C60 has been used to produce solvent-cast and LB films with interesting photoelec-trochemical behavior. A study of solvent-cast films of C60 on Pt rotating disc electrodes (RDEs) under various illumination conditions was reported [284]. Iodide was used as the solution-phase rednctant. The open-circuit potential shifted by 74 mV per decade of illumination intensity from a continuous wave (cw) argon-ion laser. The photocurrent versus power was measured at -0.26 V under chopped illumination (14-Hz frequency, vs. SCE) up to 30 mW cm and was close to linear. The photoexcitation spectrum (photocurrent versus wavelength) was measured at 0.02 V (vs. SCE) from 400 to 800 mn and found to be... 

C07-0125. The argon-ion laser has two major emission lines, at 488 and 514 nm. Each of these emissions... 

In-sltu Raman experiments were performed on a Spex 1401 double monochrometer Raman spectrometer, using a Spectra-Physlcs Model 165 argon Ion laser with an exciting wavelength of 5145 A. The In-sltu Raman cell consists of a quartz tube situated In a temperature controlled heating block. The Raman spectra were collected In the 180° backscatterlng mode. 

Since chlorinated PVC is totally transparent in the near-UV and visible range, it will not absorb at 488 nm, the emission line of the argon ion laser that we intended to use to perform the carbonization. Therefore C-PVC films were first exposed to the UV radiation of a medium pressure mercury lamp in order to produce the strongly absorbing polyenes. This irradiation was carried out at room temperature in the absence of oxygen, thus preventing the formation of undesirable oxidation products. 

Since our main objective was to remove all the chlorine and hydrogen atoms from the polymer chain, C-PVC films were further exposed to the UV radiation of the medium pressure mercury-lamp. This led to a dark brown material w.hich was found to be unable to carry an electrical current, even after extended irradiation time. Therefore we turned to a powerful laser source, a 15 W argon ion laser tuned to its continuous emission at 488.1 nm. At that wavelength, the degraded polymer film absorbs about 30 % of the incident laser photons. The sample was placed on a X-Y stage and exposed to the laser beam at scanning rates in the range of 1 to 50 cm s, in the presence of air. 

Heterocyclic fluorophores based on the benzoxadiazole nucleous, namely 4-nitrobenz-2-oxa-l,3-diazole (NBD) 14 derivatives/analogs, have been widely used as derivatization reagents for analysis purposes. Examples include the amino- or thiol reactive 4-fluoro-7-nitrobenz-2-oxa-l,3-diazole (NBD-F) 15 and 4-chloro-7-nitrobenz-2-oxa-1,3-diazole (NBD-C1) 16 [45-50] and the thiol-reactive /V-((2-(iodoacetoxy)ethyl)-/V-methyl)amino-7-nitrobenz-2-oxa-1,3-dia-zole (IANBD ester) 17 [51] and 7-chlorobenz-2-oxa-l,3-diazole-4-sulfonate (SBD-C1) 18 [52], NBD-F and NBD-C1 derivatives can be excited at about 470 nm by using the relatively inexpensive and reliable argon ion lasers or newer diode pumped solid state (DPSS) lasers. NBD-F has been used as a labeling tag in various capillary electrophoresis (CE) experiments for amino acids [53-57] including the monitorization of in vivo dynamics of amino acids neurotransmitters [58]. 

Fluorescein is excited at 494 nm, which fits to the argon-ion laser line at 488 nm, a very convenient feature for many microscopy experiments. It emits at 520 nm and the emission band is far from being sharp. The broad fluorescence emission spectrum varies with pH [18]. The advantageous photochemical properties of fluorescein are its high absorption (emax = 79,000M-1cm-1) and quantum... 

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