Laser properties

The fluorescence and laser properties of symmetrically and unsymmetrically substituted 2,5-diaryl-l,3,4-oxadiazoles were experimentally studied. It has been found that symmetrically substituted molecules (e.g., 2,5-di(2-naphthyl)-l, 3,4-oxadiazole) give laser oscillation at room temperatures, while unsymmetrical 2-(2-naphthyl)-5-phenyl-l,3,4-oxadiazole does not give laser action under any conditions, even at low temperatures <2000SAA2157>. 

We will briefly describe the basis of two spectroscopic methods that are commonly used in the investigation of optically active centers in solids. As we will see, both of them constitute good examples of the usefulness of laser properties in the held of spectroscopy. 

The ICP-MS signal depends on the amount of analyte entering the plasma per second. The amount of material ablated per laser pulse is strongly dependent on the sample properties and the surface morphological features. In addition, the amount of material is dependent on the laser properties, including wavelength,... 

Since partial laser phase coherence affects both the direct terms as well as the cross terms, the extent of control is dependent on the laser properties through the relative magnitudes of ( l( ulg) (c02g))l and (l i-(w ) 2)> =1,2. To expose the dependence on the coherence of the pump field denote the terms ckc jF u>jk)dq kj)(E) by a ]- and consider the ratio of the k / j term in Eq. (5.44) to the associated diagonal terms. That is, consider the contrast ratio ... 

Theory quite naturally gives us the initial and final state resolved probabilities, but in experiment this is not always so. The internal state populations in a molecular beam are determined by the temperature of the nozzle used to produce the supersonic expansion. More than one state is present in such a beam. This has been partially overcome in recent years by Raman pumping of the incident molecular beam [66-69]. Laser beams intercept the molecular beam moving a fraction of the molecules into a particular ro-vibrational state (determined by the laser properties). With careful timing of the firing of the probe lasers, it is possible to measure changes in this fraction of molecules and measure some of the final states populated by the scattering process. 

Nevertheless, the threshold current density of GaN-based laser diodes is still almost one order of magnitude higher than in other III-V material systems. Being one of the most basic laser properties, this highlights the present lack of understanding of the lasing mechanism in nitride-based semiconductors. 

O Conner J.R., Unusual Crystal-field energy level efficient laser properties of YV04 Nd., Appl. Phys. Lett. 9 (1996), pp. 407. 

Of particular current interest are the fluorescence and laser properties of certain chelates of speciflc lanthanide ions (7, 5, 4> 44)- That a... 

Table 1. Laser properties (left-hand side) and typical applications (right-hand side)...

Table 12.1 Comparison of laser properties of small-molecule organic materials and conjugated polymers.

MQWs grown on sapphire substrates. The optical and laser properties of the MQW heterostructures grown on silicon substrates are presented in additional paper for Nanomeeting-2003 . 

Steinbruegge KB, Hennigsen T, Hopkins RH, Mazelsl R, Melamed NT, Riedel EP, Roland GW (1972) Laser properties of Nd and Ho doped crystals with the apatite structure. Appl Optics 11 999-1012 Stokes GG (1852) On the change of refrangibility of light. Phil Trans 142 463-562... 

Ledig M, Heumann E, Ehrt D, Seeber W (1990) Spectroscopic and laser properties of Cr ", Yb ", Er " fluoride phosphate-glass. Opt Quant Electron 22 S107-S122... 

Seeber W, Ehrt D, Ebendorffheidepriem H (1994) Spectroscopic and laser properties of Ce " -Cr -Nd co-doped fluoride phosphate and phosphate-glasses. J Non-Cryst Solids 171 94-104... 

Fig. 9.14 Laser properties of the Nd BZMT eeramies. Reproduced with permission from [121]. Copyright 2011, Elsevier...

Eradat-Oskouvei, N., et al. 1997. Laser properties of luminescent conducting polymers in open resonators. Proc SPIE 3148 352. 

This linking of the macroscopic laser properties with the microscopic (fye ones may be enhanced by further consideration of these results. In the gain expressions Eqs. (5) and (7) neglect the reabsorption term in tuning range. Then the small signal gain per pass of the dye medium is... 

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