An apparatus has a waveguide that includes a multiferroic medium. The TPA member is laterally movable on the front section between an unlocked position and a locked position. This enables maximum light scattered off stacking fault defects, to be directed into a collector, enhancing the abilities of the system to classify the defect from other type of defects. Responsive to the acceptance, the at least one server may cause: a gift certificate to be issued to the payee; value in the amount of the payment minus a service fee to be transferred to a merchant associated with the at least one third party offer; and to cause the check to be voided. A new time slot for transmission between a first and a second station is selected based at least on timing information indicating the times of existing time slots used by stations whose transmissions can be reliably received by at least one of the first and second station. The invention further relates to a surface micro-mechanical process for fabricating such microfabricated capacitive ultrasonic transducers.