Patent ID: 6947193
Filing Date: 2005-09-20
Classification: G02F

Abstract:
1. A phase modulator for changing the phase of light, which is transmitted through the phase modulator, by a predefined phase shift φ, using at least one electro-optical, double-refractive delay element (LC 1 , LC 2 , LC 3 , LC 4 , LC 5 , LC 6 , LC 7 ) having an indicatrix that is rotatable as a function of φ, wherein at least one mirror (SP) is included which reflects the light being transmitted through the delay element of the modulator back into at least one of the delay elements, so that the light propagates through this element at least twice; and φ is any value between 0 and 360°; and means are included for directing the polarization of the light during transmission through the modulator on at least one closed path on the Poincaré unit sphere, the total encircled surface being equal in terms of absolute value to 2φ.