Laser continuous

In the case of InP-GalnAsP buried ridge structure lasers, continuous threshold currents of 8.2 mA at 300 K have been achieved (Kazmierski et al., 1989). This value compares favorably with the thresholds around 10 mA when proton implantation is used for insulation of the same structure. High maximum output power above 15 mW CW per facet and good maximum external quantum efficiency of 0.25 were found on the plasma hydrogenated structures. 

Before the invention of lasers in 1960 (Maiman), radiation emitted by the mercury arc, especially at 435.8 and 404.7 nm, has been u.sed for exciting Raman spectra (Brandmiiller and Moser, 1962). Today, most types of lasers ( continuous wave (cw) and pulsed, gas, solid state, semiconductor, etc.), with emission lines from the UV to the NIR region, are used as radiation sources for the excitation of Raman spectra. Especially argon ion lasers with lines at 488 and 515 nm are presently employed. NIR Raman spectra are excited mainly with a neodymium doped yttrium-aluminum garnet laser (Nd YAG), emitting at 1064 nm. 

Current research is investigating two approaches to achieve inertial confinement fusion. In the direct approach a short wavelength, high intensity laser pulse is focused directly on the pellet containing the fusion fuel. The outer layers of the pellet are violently vaporized and heated to a high temperature. This process is termed ablation. The expansion of the hot outer layer compresses the inner core of the pellet causing it to implode. Energy from the hot outer layers and the laser continue to heat the inner core until it reaches fusion temperatures. 

Kr 1215.6 3x10" at 10 W 12 48 Requires high power laser Continuous tunability... 

Dascalu T, Acosta-Oitiz SE, Pavel N (2000) Nd YAG laser continuous wave pumped, Q-switched by hybrid passive-active methods. Rev Mex Fis 46 320-328... 

In laser pyrolysis, a precursor in the gaseous form is mixed with an inert gas and heated with CO2 infrared laser (continuous or pulsed), whose energy is either absorbed by the precursor or by an inert photosensitizer such as SFs. Swihart [84], Ledoux et al. [116,117], and Ehbrecht and Huisken [118] prepared Si nanoparticles by laser pyrolysis of silane. By using a fast-spinning molecular beam chopper, Si nanoparticles in the size range of 2.5-8 nm were deposited on quartz substrates to study quantum confinement effects [116]. Li et al. [119] improved the stability of the Si nanoparticles ( 5 nm) by surface functionalization and obtained persistent bright visible photoluminescence. Hofmeister et al. [120] have studied lattice contraction in nanosized Si particles produced by laser pyrolysis. The method has been used to synthesize metal nanoparticles as well (see Table 2.1). Zhao et al. [121] obtained Co nanoparticles by laser pyrolysis of Co2(CO)s vapor at a relatively low temperature of 44° C. Ethylene was used as a photosensitizer for CO2 laser emission. Nanoparticles... 

Figure 7.5. Schematic sketch of the printing process integrating a light source a). Furthermore, the inset shows the generation of the laser light b) by the diode laser chips c). Integration of many diode laser chips and optical components results in a line shape laser continuously emitting a homogeneous laser line d) shining on the printed substrate in a press machine e) (source a) [PIT 03J, b)-d) Philips Photonics, www.philips. C(m/photonics, e) [HTT14])...

Although development of all lasers continues to grow, there is an unmistakable trend away from gaseous molecular lasers. At the ultra high power levels, the focus is shifting away from gas lasers to free electron lasers. This is paralleled by a trend... 

R.J. Butcher, R.B. Dennis, S.D. Smith The tunable spin-flip Raman laser Continuous wave molecular spectroscopy. Proc. Roy. Soc. London 344, 541 (1975)... 

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