Polarization-maintaining near-field optical probes.
We demonstrate that tapered optical fibre probes can be easily modified in the taper cone to realize an electric dipole producing a well-defined near-field polarized light. This novel structure is made of a Short-cut Double C-shaped probe design combined to the usual full metal coating near the tapered end of the fibre. Hence, the cone at the apex of the probe is excited by an equivalent dipole whose spatial orientation is dictated by the probe geometry, regardless the polarization state of the incoming light. Properties and performances of such a configuration are first predicted by a finite-difference time domain simulation, showing that the near field coming out from the probe is linearly polarized. Following this novel design, a probe prototype is manufactured and tested. Its measured polar diagram confirms the polarization maintenance property in the near field.
Patanè
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S
Dipartimento di Fisica della Materia e Tecnologie Fisiche Avanzate, Università di Messina, Salita Sperone 31, I-98166 Messina, Italy.
Cefalì
E
E
Spadaro
S
S
Gardelli
R
R
Albani
M
M
Allegrini
M
M