CONTROLLED POLARIMETRY OPTICAL SENSOR BASED ON LITHIUM COLUMBATE FOR MEASURING AC AND DC ELECTRIC FIELDS

摘要

The invention relates to an optical sensor for measuring alternating and direct current electric fields. According to the invention, the sensor consists of a light source (1) which emits a depolarized coherence light which is propagated, through an optical fiber (2) and a coupling (4), up to a probe (6), the intensity of the light modulated by the probe (6) being measured by a photo diode (5) coupled to the optical fiber (2) by means of a Y-shaped derivation (3), where the probe (6) comprises an electro-optical crystal (10) of "z-cut" type LiNbO, with physical axes parallel to the crystallographic axes, whose birefringence characteristics are modulated by the electric field they contact, the crystal (10) being confined, on the one hand by a polaroid (8) and a λ /4 delay plate (9), and on the other hand, by a λ /8 delay plate (11) and a dielectric mirror (12), and for aligning the light beam to the analyzing assembly which forms the probe (6), a GRIN lens (7), which is coupled to the optical fiber (2), is introduced into a unit (14) aligned to the polaroid (8).