Abstract: A variable optical attenuator comprises a portion of a waveguide through which optical energy can propagate having a side surface through which optical energy can be extracted; a layer of thermo sensitive material having controllable optical properties, covering the side surface of the portion; a helicoidal heating element wrapped around the waveguide and covering at least the layer. The helicoidal heating element can be used to control the optical properties of the material by inducing a thermal transfer profile on the material using the heat dissipation of the heater through the material; wherein a wave propagation in the waveguide is influenced by the optical properties of the material controlled by the heating element.

Abstract: A device for raising and centering 45 r.p.m. records on a standard turntable having a central spindle. The device fits around the spindle and completely fills the large hole of 45 r.p.m. records. Four radially outwardly extending lifting arms project through corresponding slots made in the cylindrical housing of the device. A vertically displacable circular cap is mounted at the upper portion of the housing and is adapted for manual depression. The internal construction of the cap and housing is arranged to raise the arms and a record lying thereon by lever action when the cap is depressed against the inner portions of the arms.