Nonlinear self-focusing

Materials are also classified according to a particular phenomenon being considered. AppHcations exploiting off-resonance optical nonlinearities include electrooptic modulation, frequency generation, optical parametric oscillation, and optical self-focusing. AppHcations exploiting resonant optical nonlinearities include sensor protection and optical limiting, optical memory appHcations, etc. Because different appHcations have different transparency requirements, distinction between resonant and off-resonance phenomena are thus appHcation specific and somewhat arbitrary. 

The transmittance of the structure A depending on the input power P was evaluated via calculation of Tfz) (Fig.l3) and T2 z) (Fig.l4). It is seen that self-focusing of the light beam in the core of nonlinear waveguide increases with input power, but rate of the increase diminishes so that for the powers P > 7 (a = 1.8 pm) and P > 4 (a = 3.0 pm) the dependence is weak. Negative slope of the curve in this range results from the mentioned above soliton-like... 

In the structure A, the transverse profile of the initial pulse varies behind the junction due to the self-focusing effect. In the nonlinear waveguide of the structure, a fraction of an initial pulse power is emitted from the guiding region (Fig. 19). 

Z-scan8 is a technique used to derive the nonlinear refractive index intensity coefficient n2 (from which 3) and y can be determined) by examining self-focusing or self-defocusing phenomena in a nonlinear material. Using a... 

Nonlinear optical studies were carried out using a combination of nonlinear absorption, self-focusing and degenerate four wave mixing measurements. The measurements were made using a Quantel Nano-Pico system that permits operation at either 10 ns or 100 ps pulse lengths at 1064 nm. The 10 ns pulses were TEM mode and temporally smoothed to a near gaussian (H). 

Other commonly measured x interactions are those occurring with degenerate frequencies. Such interactions include phenomena such as four-wave-mixing, self-focusing, two-photon absorption, and CARS. If a single laser beam is focused into a material, the three applied fields interacting through the nonlinear tensor are coincident, and the interpretation is very similar to that for the... 

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