This magical device allows to user to listen to conversations taking place inside a room without the need to enter the room. It works by transmitting an invisible IR-beam to the window of the target room. The beam reflects on the windowpane, which is already vibrating because of the sound waves emanating from speech. In accordance to the law of optics, the beam is reflected from the windowpane so that the angle of incidence is equal to the angle of reflection. The device then picks up the reflected beam and optical signals are converted into electronic signals. The picked up speech is filtered, amplified and recorded. However, for good results, the window must be a smooth-surface glass (single or double glass thermo pane). This is because sound wave vibrations reflect off smooth-surface glass only. Rippled or grained glass is not a suitable surface from which to record.

Since the transmitter and the receiver are built into standard single lens reflex cameras, they are hard to detect.

LAS-MIC consists of three parts:


• Laser Transmitter
• Laser Receiver
• Amplifier Unit with Audio-Recorder

Sound wave vibrations which reflect off smooth-surface glass (single or double glass thermo pane). Transmitter laser's angle of incidence equals the angle of reflection to the receiver. Rippled or grained glass will not provide a suitable reflecting surface from which to record.

When interior and exterior sound wave reflections cause acoustic interference, they filtered and modulated by the LAS-MIC 's receiving system. The transmission can be fine-tuned by using a modulated search tone or by adjusting the placement of the receiver. To further refine results, the user can edit tape recordings.

Technical Specifications