Two-dimensional mapping of electro-optic phase retardation in lithium niobate crystals by digital holography.
We demonstrate accurate two-dimensional mapping of the phase retardation induced by the electro-optic effect in lithium niobate crystals. Off-axis digital holography is used to investigate congruent z-cut crystals. The spatially resolved optical path difference is interferometrically measured while a linearly rising voltage ramp is applied to the crystal. This procedure provides information on the uniformity of crystals' electro-optic properties and offers the ability to detect the presence of defects that is of fundamental importance for reliable processing of photonic devices.
de Angelis
M
M
Istituto di Cibernetica del Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, 80078-Pozzuoli (NA), Italy. marella.deangelis@na.infn.it
De Nicola
S
S
Finizio
A
A
Pierattini
G
G
Ferraro
P
P
Grilli
S
S
Paturzo
M
M
Sansone
L
L
Alfieri
D
D
De Natale
P
P