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This is a more efficient process than optical parametric oscillation, and in principle can be thresholdless. In order to change the output wave frequencies, one can change the pump frequency or the phasematching properties of the nonlinear optical crystal. This latter is accomplished by changing its temperature or orientation or quasi ...
ASE is produced when a laser gain medium is pumped to produce a population inversion. Feedback of the ASE by the laser's optical cavity may produce laser operation if the lasing threshold is reached. Excess ASE is an unwanted effect in lasers, since it is not coherent, and limits the maximum gain that can be achieved in the gain medium. ASE ...
Laser linewidth from high-power high-gain pulsed laser oscillators, comprising line narrowing optics, is a function of the geometrical and dispersive features of the laser cavity. [29] To a first approximation the laser linewidth, in an optimized cavity, is directly proportional to the beam divergence of the emission multiplied by the inverse ...
Unlike the giant pulse of a Q-switched laser, consecutive pulses from a mode-locked laser are phase-coherent; that is, the pulses (and not just their envelopes) are identical and perfectly periodic. For this reason, and the extremely large peak powers attained by such short pulses, such lasers are invaluable in certain areas of research.
ReLEx Small incision lenticule extraction (SMILE), second generation of ReLEx Femtosecond lenticule extraction (FLEx), is a form of laser based refractive eye surgery developed by Carl Zeiss Meditec used to correct myopia, and cure astigmatism.
On the other hand, the properties of laser light can be understood only if we assume that the transitions of the individual electrons occur in a correlated fashion. [...] Above laser threshold the coherent field grows more and more and it can slave the degrees of freedom of the dipole moments and of the inversion. Within synergetics it has ...
The coherence time, usually designated τ, is calculated by dividing the coherence length by the phase velocity of light in a medium; approximately given by = where λ is the central wavelength of the source, Δν and Δλ is the spectral width of the source in units of frequency and wavelength respectively, and c is the speed of light in vacuum.
A theoretical definition of the coherence is given by the degree of coherence, using the notion of correlation. Generally, two or more waves are superimposed and as the phase difference between them varies, the power or intensity (probability or population in quantum mechanics ) of the resulting wave oscillates, forming an interference pattern.