Resolution, frequency

Microwave spectroscopy is used for studyiag free radicals and ia gas analysis (30). Much laboratory work has been devoted to molecules of astrophysical iaterest (31). The technique is highly sensitive 10 mole may suffice for a spectmm. At microwave resolution, frequencies are so specific that a single line can unambiguously identify a component of a gas mixture. Tabulations of microwave transitions are available (32,33). Remote atmospheric sensing (34) is illustrated by the analysis of trace CIO, O, HO2, HCN, and N2O at the part per trillion level ia the stratosphere, usiag a ground-based millimeter-wave superheterodyne receiver at 260—280 GH2 (35). 

The He-Ne laser described above is basically a single-frequency device and therefore its resolution is useful primarily as a frequency or dimensional standard. Tunable dye lasers have been devised, however, which operate in the visible region and have linewidths approaching 100 Hz. More common lasers, readily available commercially, have resolution (frequency/linewidth) in the range of 10 to 10°. 

Seligson, 1970] Seligson, C. (1970). Comment on high-resolution frequency-wavenumber spectrum analysis . Proc. IEEE, 58 947-949. 

Fig. 8. The components of the laser system. The high power XeCl excimer laser pulse triggered my the muon entrance detector is converted in two steps to a high quality 7 ns long pulse of 708 nm which is shifted to the desired 6 pm light inside the multipass Raman cell. The light is injected into a multipass cavity to effectively illuminate the muon stop volume inside the PSC solenoid. High resolution frequency selection is provided by injection of a cw Ti Sa laser...

Vessot RFC, Mattison E M, Levine M W and Walsworth R L 1992 "Status of local oscillators for operating ultra-high resolution frequency discriminators as frequency standards", 24 Annual PTTI Applications and Planning Meeting, VA (USA), Dec. 1-3... 

Although a simple Fourier transform relationship can exist between a high spectral resolution frequency domain experiment and a time-domain quantum beat experiment, whenever the excitation and detection steps involve electromagnetic radiation of different spectral, spatial, or temporal characteristics, the intrinsic information content of time and frequency domain experiments needs not be identical. The format in which the information is presented may be more transparently interpretable in either the time or frequency domain. 

Capon J (1969) High-Resolution Frequency-Wavenumber Spectrum Analysis. 

J.J. Snyder An ultrahigh resolution frequency meter . Proc. 35th Ann. Freq. Control USAERADCOM May 1981. Appl. Opt. 19, 1223 (1980)... 

At lower temperatures [66, 67, 190-196], the techniques measure the other relaxation processes which are faster than the primary and secondary relaxations. Measurements have found such a fast relaxation process or processes. From the incoherent-neutron-scattering function, S(q, a>, T), the elastic part of the scattering, Se (q, Aco, T), is operationally defined by the integral of S q, co, T) over CO within —Aco < co < Aco, where q is the momentum transfer and Aco is the resolution frequency width of the spectrometer. After normalizing 5ei(, Aco, T) measured at temperature T by its value at r = 0, Se q, Aco, T = 0), one defines a Debye-Waller factor W q, Aco, T) and a mean-square displacement u T)) of the fast relaxation by... 

New insights on atomic-resolution frequency-modulation Kelvin-probe force-microscopy imaging of semiconductors. Phys. Rev. Lett., 103, 266103. 

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