Phase-matched second harmonic

Fig. 1. (a) Phase matched second harmonic generation (2cJ = 0.49 fiTo) at cj = 0.98 where = refractive index by ordinary rays and = by extraordinary rays, (b) Hypothetical anomalous dispersion phase matching at 850 nm in similar a crystal having a Lorent2ian absorption centered at 650... 

In the solid state, the phase matched second harmonic signal increases with increased polymeri zation(7 ). Figure 14 shows preliminary data for the second harmonic intensity of NTDA microcrystals polymerized under x-ray radiation. As the polymer forms, the second harmonic intensity... 

M. M. Fejer, G.A. Magel, D.H. Jundt, and R.L. Byer, Quasi-phase-matched second harmonic generation - tuning and tolerances, IEEE Journal of Quantum Electronics 28, 2631-2654 (1992). 

Chemistry of Anomalous-Dispersion Phase-Matched Second Harmonic Generation... 

Our recent report(1) on ADPM SHG (Anomalous-Dispersion Phase-Matched Second-Harmonic Generation) addressed the physics of ADPM, a... 

Besides the phase of the fundamental mode, strictly speaking, the preferred phase, many other characteristics have been studied in [226]. Because a large mismatch was chosen, they have lacked any trend, but an interesting oscillatory behavior has been discovered for the initial two-mode coherent state. Within each period, the phase-matched second-harmonic and second-subharmonic generation processes can be prepared. The model of an ideal Kerr-like medium [223] have been considered for a comparison with cascaded quadratic non-linearities. It follows that these nonlinearities exhibit not only self-phase modulation in the fundamental mode but also a cross-phase modulation of the modes that can be considered for a nondemolition measurement. 

As the transition is to a particular molecular electronic manifold, we have utilized the convenient density of states representation in the expressions. We see that the rate at which the exited state is populated depends on the position of the molecule, through I 2—and also on the molecular orientation, through the matrix elements. It is this I term that produces the grating within the sample. We note here that the periodicity of the grating, determined by eI(2k2-k3 ) R = e (2k 3 )-r is exactly that required for phase-matched second-harmonic generation from the probe beam, where the signal is created in precisely the opposite direction to the harmonic pump beam. 

FIG. 11.20 Periodic self-organization for perfectly phase-matched second harmonic generation. ... 

Phase-matched second harmonic generation in single crystal polymers was first observed in 2-methyl-4-nitroaniline substituted diacetylene polymers. Subsequently, a number of other diacetylene structures... 

In this paper we report phase-matched second-harmonic generation in nonlinear optically active Langmuir-Blodgett (LB) film waveguides both by mode conversion and by use of the Cerenkov-type configuration. The experiments were done in 2-docosylamino-S-nitropyridine (DCANP) LB films (Hg.l). The synthesis, the optimum conditions for LB film transfer and the linear and nonlinear optical properties of this material have been described elsewhere [4-6]. 

J. Halbout, S. Blit, W. Donaldson, Ch.L. Tang Efficient phase-matched second harmonic generation and sum-frequency mixing in urea. IEEE J. QE-15, 1176... 

G. Nath, S. Haussuhl Large nonlinear optical coefficient and phase-matched second harmonic generation in LilOs. AppL Phys. Lett. 14, 154 (1969)... 

Waveguiding combined with x and x processes in polydiaoetylene multilayers may open a wide range of applications to optical switches and frequency multipliers in integrated optics, data storage, and memory technologies. Current research activities are focussed on amphiphilic compounds exhibiting a phase matched second harmonic generation , as for example... 

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