Methods and systems for detecting radiation for example, terahertz radiation, with the aid of acoustic signal generation and detection include: directing an optical beam into a volume of gas; ionizing at least a portion of the volume of gas with the optical beam to produce a plasma; and detecting an acoustic signal produced from an interaction of a radiation wave with the plasma. The second hook assembly selectively pivots under force of an actuator relative to the first hook assembly by an actuator. By unfolding the leaf an extended paper tray is provided that nevertheless folds down into a compact configuration when the printer is not in use. This reduction in emissions rate come at the cost of a small performance reduction. A lower rail is mounted between the lower ends of the end posts in their blind holes with its slot facing upward. The differential amplifier is adapted to receive differential signals having been differentially converted to single-ended convert the received differential signals into a single-ended signal.