Abstract: An optical attenuator for attenuating a collimated beam of light propagating along an optical path while preserving the composition of polarization of the collimated beam of light is disclosed. The optical attenuator comprises a beam attenuator for attenuating a portion of the collimated beam of light when a portion of the beam attenuator is disposed within the optical path. The beam attenuator has a cross section along a plane perpendicular to the direction of propagation of the collimated beam of light of the portion of the attenuator in the shape of a wedge. The attenuation is varied using a controller for moving the beam attenuator in order to vary a size of the portion of the wedge within the optical path.

Abstract: An optical switch has a stepping motor with a fiber faceplate on which are mounted end portions of output optical fibers terminating in GRIN lenses. The end portions are arranged along a pitch circle. The faceplate is spaced from the stepping motor and the diameter of the pitch circle is smaller than the diameter of the stepping motor, the output fibers diverging from the faceplate towards the motor and beyond in a space-saving arrangement. The stepping motor drives a movable arm with attached end portion of an input optical fiber, also with a GRIN lens, into one of a plurality switching positions. The connection between the fibers and the lenses and also the relative axial arrangement of the paired lenses in the switching positions is offset to reduce or minimize the reflection of light transmitted from the input fiber to the output fiber, back to the input fiber.

Abstract: A device is provided for controllably moving an optical element such as an attenuator, into one of a plurality of positions. The device includes a rotatable, cylindrical member having a face cam that is an endless cammed surface for supporting and moving a cam follower. As the cammed surface is rotated, the cam follower resting upon it moves the optical element in a controlled manner. A gearing means in the form of a toothless planetary gear box is coupled to the cylindrical member and provides fine control over the range of movement of the device.

Abstract: A polarization-independent optical detection apparatus for measuring light output from optical fibers comprises an optical detector having an input port for receiving input light by way of an optical path and an output for a corresponding detection signal. A polarization-transformation element is rotatably mounted in the optical path so that the input light passes through the element to reach the input port. A drive motor rotates the polarization-transformation element in a plane extending transversely of the optical path. The polarization-transforming element is selected to transform the polarization state of the input light reaching the detector, as the element spins, so that, for any given input polarization state, the time averaged electrical signal from the detector is approximately the average electrical signal from the detector over all input polarization states.

Abstract: An optical attenuator for attenuating a collimated beam of light propagating along an optical path while preserving the composition of polarization of the collimated beam of light is disclosed. The optical attenuator comprises a beam attenuator for attenuating a portion of the collimated beam of light when a portion of the beam attenuator is disposed within the optical path. The beam attenuator has a cross section along a plane perpendicular to the direction of propagation of the collimated beam of light of the portion of the attenuator in the shape of a wedge. The attenuation is varied using a controller for moving the beam attenuator in order to vary a size of the portion of the wedge within the optical path.