Patent ID: 11906828
Assignee: SIOPTICA GMBH
Field: Optics (Instruments)
Classification: CPC G | IPC F  G

Claim 0:
1. A switchable light filter switchable between a first operating mode, and a second operating mode, comprising:
a first optical element, including:
a first layer having a material with a plurality of light-absorbing transition dipole moments, and
wherein, each transition dipole moment is oriented, with a tolerance of 10° at a maximum, parallel to a first preferential direction selectable for the first optical element, such that light which is incident in the first optical element is transmitted or at least partially absorbed, depending on its incident direction relative to the first layer and depending on its polarization state;

a polarization filter which is arranged upstream or downstream of the first optical element along a light incident direction;
an electric field generator configured to selectively generate a first electric field in the first operating mode and a second electric field in the second operating mode;
a liquid crystal layer arranged between the first optical element and the polarization filter, without another polarization filter between the liquid crystal layer and the first optical element, the liquid crystal layer arranged and configured to receive the first electric field in the first operating mode and the second electric field in the second operating mode, and, depending thereon, influencing the polarization state of light passing through it so that the switchable light filter is configured to:
in the first operating mode in which the first electric field is applied, transmit at least 24% of unpolarized light which is incident in the switchable light filter parallel to the first preferential direction and, absorb at least 85% of unpolarized light which is incident in the switchable light filter at an angle of greater than 30° to the first preferential direction, and wherein the absorption takes place exclusively along a first direction, which differs from the first preferential direction, and
in the second operating mode in which the second electric field is applied, transmit at least 24% of unpolarized light which is incident in the switchable light filter parallel to the first preferential direction and absorb at least 85% of unpolarized light which is incident in the switchable light filter at an angle of greater than 30° to the first preferential direction, wherein the absorption takes place exclusively along the second direction which differs from the first direction.