An apparatus for determining the depolarization efficiency of a environment includes a transmitter, a receiver, and signal processing circuitry. The method includes once per predetermined interval of time, the transceiver transmitting a signal including multiple carriers, a plurality of the carriers including training symbols, a plurality of the carriers including information symbols. This structure of the buried portion enables to transfer electric charges stored in the photoelectric conversion part effectively. The control means forms a control signal, which adjusts the amplification of the amplifier means, from the reference signal and the sample signal. A first side of the quadrilateral cross section is connected to the light output face and includes a first angle with the light output face, wherein the first angles of the prisms continuously arranged have angle values varying in a periodic manner. The device is particularly suited for redirecting light from LED’s on a PCB to a status indicator panel thereby replacing conventional light pipes.