Picosecond-accuracy narrow-pulse width transistor-transistor logic (TTL) signal acquisition method based on phase shift AND operation

Abstract

The invention relates to the technical field of range gated imaging, and discloses a picosecond-accuracy narrow-pulse width transistor-transistor logic (TTL) signal acquisition method based on phase shift AND operation. The method comprises the following steps of: dividing each path of TTL pulse triggering signals comprising pulse laser triggering signals and intensified charge coupled device (ICCD) triggering signals in range gating into two paths of time sequence signals with completely identical phase and amplitude by using a multipath generator; delaying one of the divided two paths of signals by adopting a picosecond-accuracy delay line technology to produce a phase shift between the two paths of signals; and then causing the two paths of signals to pass through a logic AND gate for a logic AND operation, thereby compressing a pulse width. By the method, the phase shift between the two paths of signals is accurately controlled to obtain high-accuracy pulse width signals and higher pulse width compression accuracy, and the compressed pulse width can be close to the limit of the TTL signal, namely the order of magnitude of 1ns; and the method is applied in the field of gating application such as range gated three-dimensional imaging, underwater imaging and the like with high-accuracy time sequence requirements.

Description

technical field [0001] The present invention relates to the technical field of range gating imaging, in particular to a method based on phase shifting and obtaining picosecond precision narrow pulse width logic gate circuit (Transistor-Transistor Logic, TTL) signal. Background technique [0002] One of the key technologies of range-gated imaging is synchronous control technology, that is, to synchronize the switching of the laser and the gate of the enhanced charge-coupled device (ICCD). When the signal light reflected by the target has not reached the gate, the gate The gate is always closed, and when the signal light reaches the gate, the gate is suddenly opened to form an image. The opening time and duration of the gate determine the imaging distance and imaging depth, respectively. [0003] High-precision delay technology and pulse width technology are the key to strobe imaging, especially the timing control technology of three-dimensional imaging. In gated 3D imaging ...

AI Technical Summary

Problems solved by technology

However, at present, the clock control accuracy of the timing control system based on FPGA is mostly on the order of nanoseconds. This is mainly because the hardware characteristics of the FPGA itself make it difficult to continue to increase the clock frequency. At present, take the Virtex-6 series FPGA newly launched by XILINX as an example. The highest clock frequency is 600MHZ, that is, the highest clock control accuracy is 1.67ns, and the synthesized frequency will be less than this value in actual use

[0010] Except for the digital delay pulse generator, the control accuracy of the above methods is in the nanosecond or sub-nanosecond level, which is difficult to meet the high-precision timing requirements of gated three-dimensional imaging and underwater imaging.

Although the delay accuracy of the digital delay pulse generator is high, taking DG535 as an example, the delay accuracy is 5ps, but the minimum pulse width is 4ns, and the volume is large, which is not conducive to the miniaturization of the system.

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