RESUMEN
Matched filtering of megahertz-bandwidth signals by use of holograms recorded in a photorefractive crystal is demonstrated. Holographic recording of rapidly varying signals has heretofore been hampered by the relatively slow response of photorefractive crystals. For the first time, to our knowledge, synchronization between waveforms and short optical sampling pulses is used with acousto-optic electrical-to-optical conversion to build up static holograms of rf waveforms in a SBN crystal. Readout with a continuous input signal yields a time-resolved correlation with stored waveforms.
RESUMEN
Using multiple signal beams and controlling their relative phases, we demonstrate angular multiplexing of phase-sensitive holographic gratings in a photorefractive crystal. Interference between diffracted signal beams determines total diffracted intensities as a function of the relative phases between input signals compared with those between gratings. Complete constructive and destructive interference produce maximum and near-zero diffraction, respectively, from orthogonal gratings.
RESUMEN
Radiative renormalization has been used to deduce and describe electromagnetically induced transparency succinctly in four-wave mixing for both one and two strong fields. We find both additive and nested renormalization terms and give a prescription for obtaining renormalized expressions starting from perturbation theory solutions. The advantages of using a second strong field are also discussed.
RESUMEN
Self-aligning optical heterodyning is demonstrated with an acceptance angle as large as 40 degrees . The receiver consists of a strontium barium niobate (SBN) crystal, a detector, and collecting lenses. The incoming beam interferes with the local oscillator to create a real-time grating in the SBN crystal, which diffracts and aligns the signal with the local oscillator. Heterodyne detection occurs as long as the written grating can diffract the input signal. All alignment requirements between the signal and local oscillator are automatically satisfied by the diffraction process, which permits the large acceptance angle. Insensitivity with respect to crystal orientation and background radiation has also been demonstrated.
RESUMEN
The seven papers making up this assessment are based on the Workshop on Nonlinear Optical Materials held in April 1986.
RESUMEN
It is shown that parametric mixing through chi((3)) of two injected laser lines can provide index modulation sufficient for the mode locking of the semiconductor laser. Numerical estimates indicate that picosecond pulses with 100-GHz repetition rates should be possible with a few watts of external laser power.
