Laser spectrum

To test the influence of a change in the ambient refractive index on the laser spectrum, the CBNL was immersed in a specially designed beaker containing index-matching fluids with different index of refraction. For each fluid, the emitted spectrum is measured (fpump 2.5 mW). 

Fig. 24 Tunable-diode-laser spectrum of RQ0 of v9 of ethane. Trace (a) is the average of 250,000 scans and exhibits linewidths of 0.0022 cm-1 (the Doppler width is 0.0018 cm-1). Trace (b) results from the deconvolution of the data in trace (a) using a gaussian with a FWHM of 0.0022 cm-1 as a response function. Trace (c) is the Q branch calculated using a model that includes torsional splitting effects Av = 1.95 mk. Trace (c) is calculated for Av = 0.00075 cm-1, which is less than one-half the 300 K Doppler width.

Fig. 25 Tunable-diode-laser spectrum of RQ3 of v9 of ethane. All details are the same as in Fig. 24.

Fig. 2.4. a TOF mass spectra are shown for 1,3-cyclohexadiene (1,3-CHD) and b 1,4-cyclohexadiene (1,4-CHD) at 0.8 pm with a 120-fs pulse width at an irradiation intensity of 0.6 x 1014Wcm 2. The molecular ions are indicated by M+ and the candidate for the doubly charged molecular ions is indicated by M2+. The excitation laser spectrum is indicated in the inserted Figs. 1,3-CHD+ is not in resonance with the laser wavelength, which resulted in a high yield of molecular ions, whereas 1,4-CHD+ is resonant and gave many fragments... 

It is important to be able to test the FM laser spectrum to see how closely it approaches that of an ideal FM oscillator. Mode analysis of the FM spectrum is too tedious. We have developed methods of testing the quality of the FM spectrum which involve nonlinear mixing of the FM beams. If we phase shift a part of the FM beam by 0 we obtain a modified field,... 

Figure 4. Multiline laser spectrum of Na dimer laser on B Uu transitions, excited by...

We briefly examined vibrational relaxation of l2 X,v > 20) induced by collisions with He at low temperatures. These measurements were performed by focusing state preparation and probe laser beams into the downstream region of a He free-jet expansion that had been seeded with l2-Transfer out of the initial levels u = 23 and 42 was examined at 5 K. For these conditions the probe laser spectra were quite simple and uncongested. A typical probe laser spectrum is shown in Fig. 5. The delay used to record this trace was long enough for multiple collisions to occur, so populations are seen in levels corresponding to Av = — 1 and —2 transitions. 

The IR spectra of tetrazines are found to be as expected for this system literature leading to data on simple derivatives is found in <84CHEC-I(3)531>. Some more recent literature can be found for the diode laser spectrum and analysis of the 882 cm band of -tetrazine <84JSP(107)373>, the diode laser spectrum and analysis of the 1103 cm band of -tetrazine <85JSP(l 12)340>, and the comparative study by Wiberg of azines—the effect of basis set on the calculated vibrational frequences, infrared, and Raman intensities <90JST(244)6i>. 

Figure 4. Excitation intensity (1,2) and temperature dependencies of laser modes (4, 5) and total laser spectrum (3) positions.

Note the presence of only one spot revealing the absence of parasitic reflections between parallel faces of the Nd YAG ceramic sample. The spectral distribution of the laser radiation was also measured. From the laser spectrum (not shown in this work for the sake of brevity) we have corroborated single mode laser oscillation with a linewidth of 0.25 nm., centered around 1064.4 nm peak. And, in this way, we have experimental proofs about spectral and spatial quality of continuous wave laser emission from Nd YAG ceramic waveguide structure. 

Fig. 9.28 a CW output powers with different output couplers, i.e., T = 2, 5, and 7 %, as a function of the absorbed pump power, b Laser spectrum of the Tm YAG ceramics. Reproduced with permission from [192], Copyright 2013, Elsevier... 

OlOsi Osiac, M., Ropcke, J., Davies, P.B. Infrared laser spectrum of the fundamental band of the boron monoxide free radical, Chem. Phys. Lett. 344 (2001) 92-96. 

Fig.1.13 Part of a CO-laser spectrum, showing the rotational distribution of a series of adjacent vibrational bands. (W.Bohle, private communication)...

Fig.3.8 Part of a CO-laser spectrum obtained by tuning the grating angle (see Fig.3.9). The appearing linewidth does not indicate the laser linewidth but the angular region where the gain is above threshold.

There are a number of methods to overcome this loss of atoms by optical pumping. For example, there could be two laser beams tuned for excitation out of each hfs state, the laser spectrum could be sufficiently broad to excite both hfs states, there could be an rf or microwave field that would induce hfs transitions to return atoms to the appropriate hfs state, or optical pumping could be inhibited by careful choice of experimental conditions. For a variety of carefully considered technical reasons, we employ the last of these alternatives. We use circularly polarized light and the axis provided by the magnetic tuning field to allow only excitations to a particular sublevel of the atomic excited state. The only strongly allowed decay process returns the atom to the original state. 

H. Jones. The diode laser spectrum of thallium hydride ( ° T1H and T1H) in its ground electronic state. Chem. Phys. Lett, 158 (1989) 443-446. 

To master this complexity, more flexible pulse shapes in terms of both temporal amplimde and phase were used in experiment as well as in theory. A sinusoidal phase modulation (p a>) = A sin[r(ft>—multi-pulse sequence [51,69], adjustable by the phase parameters A for the amplitude of the subpulses, T for the temporal separation of the subpulses, and (p conflolling the relative temporal phases between adjacent subpulses. 

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