Direct writing of luminescent nanostructures in lithium fluoride films by X-ray
microprobe scanning
T. Marolo, F. Bonfigli, R.M. Montereali
ENEA, Applied Physics Div., C.R. Frascati,
Via E. Fermi 45, 00044 Frascati, Rome (Italy)
R. Larciprete
CNR–IMIP, Zona Industriale, 85050 Tito Scalo (PZ), Italy
L. Gregoratti, M. Danailov and M. Kiskinova
Sincrotrone Trieste, S. S. 14, Km. 163.5, 34012 Basovizza (TS), Italy
S. K. Sekatskii and G. Dietler
Laboratoire de Physique de la Matière Vivante, IPMC, BSP, Ecole Polytechnique
Fédérale de Lausanne, CH1015 Lausanne – Dorigny, Switzerland
The continuously shrinking of the photonic structures has stimulated the development of lowdimensionality photoluminescent patterns based on visible-emitting color centers (CCs) in thin
films. In particular, Lithium Fluoride (LiF), in the form of bulk and film, treated by ionizing
radiation using versatile lithographic techniques, represents a very promising candidate for the
realization of innovative photonic devices .
Permanent fluorescent patterns based on CCs have been realized in LiF films by direct writing with
a X-ray microprobe of the ESCA Microscopy beamline at ELETTRA synchrotron in different
configuration . Nanostructures, written by scanning the LiF specimen with respect to the X-ray
beam, have been investigated by near-field optical microscope and a sub-wavelength spatial
resolution is demonstrated.
The use of this lithographic technique offers the opportunity to integrate active and passive optical
components, like waveguides and gratings, in this promising material, grown by simple and well
assessed film deposition method on different substrates. Moreover the possibility to create in a
single-step an optical active structure with a periodic modulation of the refractive index is very
promising in the development of photonic devices like Distributed Bragg Reflector and Distributed
Feedback Laser.
R. M. Montereali, Point Defects in Thin Insulating Films of Lithium Fluoride for Optical Microsystems, in Handbook of
Thin Film Materials, H.S. Nalwa ed., Academic Press, Vol.3 (2002) ch.7, pp. 399-431.R. Larciprete, L. Gregoratti, M.
Danailov, R.M. Montereali, F. Bonfigli, M. Kiskinova, Appl. Phys. Lett. 80, 3862 (2002).