Programmable liquid-crystal devices for high-resolution spatial shaping of ultrashort-pulsed laser beams promise to be an alternative approach to passive microoptical structures. In former experiments we demonstrated that depositionfabricated nanolayer lenses and axicons can serve as low-dispersion, damage resistant, ultrabroadband microoptical components. With small-angle layer microaxicons, robust wavefront sensors and 2D autocorrelators were built up with them which took advantage of stable and tilt-independent nondiffracting propagation. The flexibility of the thin-film design, however, was limited with respect to the dynamic range. For adaptive applications, information encoding, image transfer and data storage, addressable and phase variant components are required. Recently, phase-only reflective liquidcrystal- on-silicon spatial light modulators (LCoS-SLMs) became available. By analyzing the pulse transfer behavior in spectral and temporal domain it was shown that selected versions of LCoS-SLMs are capable to shape 10-fs pulses with marginal distortion. Variable arrays of pulsed Bessel-like beams and nondiffracting complex patterns were shaped experimentally and related applications are discussed. The adaptive correction of aberrations in nondiffracting tubular beams on microscale is demonstrated. The unique properties of programmable beam patterns of well controlled propagation promise the coverage of fields of entirely new photonic applications.

Date Published: 13 May 2010
PDF: 8 pages
Proc. SPIE 7716, Micro-Optics 2010, 77160P (13 May 2010); doi: 10.1117/12.856370

Published in SPIE Proceedings Vol. 7716:
Micro-Optics 2010
Hugo Thienpont; Peter Van Daele; Jürgen Mohr; Hans Zappe, Editor(s)