Laser optical resonator

Since the separation energies between these sharp features in the 1D DOS are strongly dependent on the CNT diameter, a change in the laser excitation energy may bring into optical resonance a CNT with a different diameter. However,... 

All lasers have the following three fundamental components (see Figure 1). The gain medium, the business end of the laser, is the medium in which excited states are created which will produce stimulated emission. The exciter is the source of energy for production of the excited states in the gain medium. Finally, the optical resonator determines the directionality, wavelength selectivity, optical feedback, polarization, and other characteristics of the stimulated emission from the gain medium. 

To use the OFRR as a biosensing device, the optical resonant mode is excited and the resonant frequency is measured continuously in real time. The conceptual measurement setup is illustrated in Fig. 14.3. Laser light from a distributed feedback (DFB) laser is delivered to the OFRR using fiber optic cable. One method that has been used to excite the resonant modes is to place a tapered fiber optic cable with a diameter less than 4 pm in contact with the OFRR. The evanescent field of the tapered fiber overlaps with the evanescent field outside of the capillary wall, which enables mode coupling between the two media24. 

The levitated droplets and droplet dye lasers may conveniently be operated with acoustic frequencies below the critical for excitation of droplet vibrational modes, (17.4), to facilitate stable and highly spherical optical resonators. 

The radiation can be amplified by an optical resonator, which, in the simplest case, is constituted by the semiconductor itself, shaped in the appropriate manner for instance, by cutting the crystal so that two end faces are parallel to each other, and exactly perpendicular to the laser beam emitted by the junction (see Fignre 2.14). 

Allen et a/. (1991) performed these computations for 1-octadecene droplets, and they measured the evaporation rate of the droplets as a function of laser power. To determine the absolute irradiance /, of the laser beam, they also measured the force on the particle exerted by the laser beam using the techniques discussed above. The photon pressure force is given by Eq. (87), which involves the complex refractive index. The real component of the refractive index n was determined from optical resonance measurements, and the imaginary component was obtained iteratively. That is, they assumed a... 

A complex dynamical behavior was experimentally and numerically found in a system of spin- atoms in an optical resonator with near-resonant cw laser light and external static magnetic field [69]. Three-dimensional Bloch equations were solved, and a chaotic motions was found and compared with experiment. 

A crucial part of these experiments is the preparation of the sodium atoms into the excited state by laser optical pumping. A commercial single-mode Rhodamin 6G continuous wave (cw)-dye laser (Spectra Physics model 580) is used, having 20-40-mW single mode output power when tuned to the sodium resonance line. 

Besides the equilibrium radiation considered in this article, the concentration limits can also be affected by chemiluminescence which arises if, in the combustion, chemical compounds form with a non-equilibrium energy distribution along the degrees of freedom of molecules or an atom. The chemiluminescence itself cannot lead to the appearance of a flame propagation limit if only one specific energy fraction is emitted. However, forced luminescence in an optical resonator (in combustion lasers) can lead to quenching of the flame. 

Fig. 6. Density of non-condensed fraction of the gas as the trap depth is reduced along the cooling path. The density is measured by the optical resonance shift, and the trap depth is set by the rf frequency. The lines (dash, solid, dot-dash) indicate the BEC phase transition line, assuming a sample temperature of (l/5th, l/6th, l/7th) the trap depth. The scatter of the data reflects the reproducibility of the laser probe technique and is dominated by alignment of the laser beam to the sample...

Excitation conditions At about 10cm"1 and farther above the 0-0 transition, the excitation wavelength does not seem to influence the fluorescence spectrum. This observation points to a rapid thermalization of the exciton population.87 In contrast, the excitation power has an important nonlinear effect Above a threshold stimulated emission is observed on the 0-1400 line, at 23692 cm"1.88 The crystal behaves as an optical resonator, with laser effects, which explains the sharpness and the intensity of this line in Fig. 2.17.89... 

We now describe briefly the FIR laser magnetic resonance studies of the four molecules listed above. FeH has also been studied by mid-infrared laser magnetic resonance, and NiH by microwave/optical double resonance these investigations are discussed elsewhere. 

The NiH radical has been studied quite thoroughly, by FIR laser magnetic resonance as described here [76], but also by microwave/optical double resonance and by mid-... 

In our discussion of the far-infrared laser magnetic resonance spectrum of NiH in chapter 9, a fairly general effective Hamiltonian was presented. This Hamiltonian included terms which would produce A-doubling in a A state, an unusual situation because one requires electronic orbital angular momentum operators to connect A = + 2 and A = - 2 components [77], The effective Hamiltonian used to analyse the mi-crowave/optical double resonance spectrum of NiH was as follows ... 

A third and important requirement for lasing action is to have sufficient optical gain irrespective of the active medium. The optical gain is achieved by multiple passes of the photons through the population-inverted medium. Multiple passes of photons is achieved by placing the active medium in an optical resonator. The optical resonator consists of two or more mirrors. A typical optical arrangement for a laser system is shown in Fig. 12.13. 

In a resonance ionization mass spectrometer, one or more lasers are applied which are tuned precisely to the wavelength required for optical resonance excitation from the atomic ground state... 

Graphite furnace AAS Atomic fluorescence spectroscopy Inductively-coupled-plasma optical-emission spectroscopy Glow-discharge optical-emission spectroscopy Laser-excited resonance ionization spectroscopy Laser-excited atomic-fluorescence spectroscopy Laser-induced-breakdown spectroscopy Laser-induced photocoustic spectroscopy Resonance-ionization spectroscopy... 

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