Single-mode selection

AXIAL MODE STRUCTURE AND SINGLE MODE SELECTION 297... 

AXIAL MODE STRUCTURE AND SINGLE MODE SELECTION 299 and so we can deduce that since AE = hAv = he Av for photons,... 

An etalon is used for single-mode selection in a 1-m rhodamine 6G laser. If the dye gain bandwidth is commensurate with the width of the rhodamine 6G fluorescence spectrum shown in Problem 8.2, what etalon separations and etalon surface reflectivities would ensure that only one axial mode is selected at any time ... 

So far we have only considered the stability of the laser resonator itself In the previous section we saw that wavelength-selecting elements inside the resonator are necessary for single-mode operation to be achieved, and that then-stability and the influence of their thermal drifts on the laser wavelength must also be considered. We illustrate this with the example of single-mode selection by a tilted intracavity etalon. If the transmission peak of the etalon is... 

One of the attractive features of single mode waveguides is their ability to filter the spatial field distribution. All the wavefront aberrations only result in a photometric fluctuation easy to monitor. It results in a very good calibration of the interferometric data as firstly demonstrated by FLUOR, as seen in Fig. 8 (Coude du Foresto et al., 1998). Nevertheless, care has to be taken to keep in mind that turbulence may have a spectral selectivity in the launching pro-... 

Fig. 11.2 Selected temperature profiles for the DMSO at different power inputs (fluoroptic ther-single-mode heating of internal vinylations in mometer, Smith prototype).

Selected temperature profiles for the reactions represented in Eqs (11.13) and (11.14) are shown in Fig. 11.2. Note that the high tan 5 value of DMSO (0.825) [5] results in extensive heating even at a relatively modest power input of single-mode irradiation. 

The development in microwave chemistry has been remarkable during the last few years from the first reports in which, typically, domestic ovens were used to modern applications with state-of-the-art single-mode cavities. We believe that it is today possible today to develop robust microwave-assisted methods for nearly any reaction that needs an external heat source and we have proved it is possible to perform transition-metal catalyzed reactions very cleanly and selectively. 

The FPI principle can also be used to develop thin-film-coating-based chemical sensors. For example, a thin layer of zeolite film has been coated to a cleaved endface of a single-mode fiber to form a low-finesse FPI sensor for chemical detection. Zeolite presents a group of crystalline aluminosilicate materials with uniform subnanometer or nanometer scale pores. Traditionally, porous zeolite materials have been used as adsorbents, catalysts, and molecular sieves for molecular or ionic separation, electrode modification, and selectivity enhancement for chemical sensors. Recently, it has been revealed that zeolites possess a unique combination of chemical and optical properties. When properly integrated with a photonic device, these unique properties may be fully utilized to develop miniaturized optical chemical sensors with high sensitivity and potentially high selectivity for various in situ monitoring applications. 

The last method has been pushed to an impressive sensitivity by putting the probe inside the cavity of a cw dye laser oscillating on several modes close above threshold. The sensitivity of such a broad-band dye laser to selective intracavity absorption on a single mode is proportional to the number of oscillating modes due to... 

The limit cycle is an attractor. A slightly different kind occurs in the theory of the laser Consider the electric field in the laser cavity interacting with the atoms, and select a single mode near resonance, having a complex amplitude E. One then derives from a macroscopic description laced with approximations the evolution equation... 

Keywords Vibrational spectroscopy scanning tunneling microscopy and spectroscopy conductance inelastic conductance single-molecule chemistry controlled manipulation mode-selective reactivity. 

For a single excitation path (i.e., one or three photons), the only possibility for controlling the outcome of the reaction is to select the excited eigenstate by varying E, as is normally done in mode-selective processes. A completely new form of control becomes possible, however, if both excitation paths are simultaneously available. In that case, the reaction probability is... 

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