A model for analyzing the effects of material shrinkage on volume holograms is presented. This model is based on the fringe-plane rotation model used for describing the effects of plane-wave grating holograms that undergo shrinkage. A computer was used to exercise the model for a simple input object typical of those used in digital holographic memory applications and stored as a Fourier-transform hologram. The theoretical formulation of the model is presented as well as the results of the numerical analysis.

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Two-step sequential excitation of fluorescence was produced in ICl vapor using two synchronized tunable laser sources. The pumping scheme involved the E←A←X electronic transitions with subsequent E→A transitions being observed in fluorescence.

Performance-limiting asymmetric distortion is observed in the spectra of fundamental pulses transmitted through GaAs-Al(0.9)Ga(0.1)As multilayer waveguides designed for surface-emitted second-harmonic generation. This behavior is attributed to refractive-index changes resulting from the accumulation of free carriers created by two-photon absorption in the GaAs layers. Numerical simulations of the intensity-dependent spectra by use of the separately measured two-photon absorption coefficient are shown to be in good agreement with the observed spectra.

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