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    Diffractive multifocal lenses by computer-generated holograms
    (SPIE (Society of Photo-optical Instrumentation Engineers), 2021) Kaya, Necati; Kaya, Gamze; Strohaber, James; Zhou, Junfeng; Kolomenskii, Alexandre A.; Schuessler, Hans A.
    The dynamics of rotational wave packets of laser-aligned linear molecules were studied with femtosecond laser-driven strong-field ionization (SFI). The dynamics were observed as a function of the delay between a femtosecond probe pulse and a linearly polarized aligning pump pulse. The induced nonadiabatic molecular alignment was directly monitored by the total SFI yield. The measured revival signatures were compared to the calculated degree of molecular alignment taking into account the effects of electronic structure and symmetry of the molecules. By fitting the calculated alignment parameter to the measured experimental data, we also determined the molecular rotational constants of N2, CO, O2, and C2H2 gas molecules.
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    Öğe
    Diffractive multifocal lenses by computer-generated holograms
    (SPIE, 2021) Kaya, Necati; Kaya, Gamze; Strohaber, James; Zhou, Junfeng; Kolomenskii, Alexandre A.; Schuessler, Hans A.
    Diffractive lenses are optical elements commonly used in many applications owing to their simple and compact design. A multifocal diffractive lens enables the simultaneous focusing of an incident laser beam on several positions along the optical axis. The distances between the focal points and the energy densities in the foci can be changed by varying grating parameters, i.e., the modulation depth and the grating period. This requires grating structures that have to be fabricated for each targeted optical arrangement. Even though some methods for designing diffractive lenses with variable focal positions are available, they do not provide real-time control over the energy distribution and focal locations of the foci. We aimed to develop coaxial or multiaxial multifocus diffractive lenses with computer-generated holograms. The focal distances and energy densities in the foci can be dynamically controlled by programmable holographic codes. The generated holographic lenses can be used for imaging with dynamic repositioning of created images fast and easily. Such a holographic diffractive lens can withstand a highly intense laser radiation, so it can be used in nonlinear optics experiments and can be employed for high harmonic generation, pump-probe experiments, optical tweezers, filamentation, and other applications. © 2021 Society of Photo-Optical Instrumentation Engineers (SPIE).