The underwater acoustic signal can cause surface wave motion at the water-air interface and hence modulate the magnitude of the laser beam falling on the water surface.

A research was made on detecting underwater acoustic signals using laser.

The laser detection of underwater acoustic signals exploited a laser receiving technique.

Medium and low frequency underwater acoustic signals detecting with laser interferometry

A new method has been developed to detect real-time underwater acoustic signals with laser and a corresponding test system has been built.

A testing installation established by using the proposed method can detect underwater acoustic signals,which verifies the adequacy of relevant theory and simulation process as well as practicability of the method.

Compared with the synchronized counter,the asynchronous counter faced two prominent difficult questions in design: One is the selection of clock signals of various triggers,the other is the correct gain of the karnaugh map at the time when the is simplified into the equation of state for varions triggers.

On the base of the traditional approaches for designing synchronous sequential circuits,a new approach for designing asynchronous sequential logic circuit is proposed in this paper where the trigger pulses can be directly obtained from sequential waveforms in sequential circuits,and the next state Karnaugh maps can be acomplished according to the state transformations caused by clock signals.

This paper introduces IBIS model and its applications in the design of computer high-speed system, and gives the waveform of clock signal simulation in detail.

With the development in computer,semiconductor and communication technology,the signal clock in a circuit system works faster and the signal rise time gets shorter.