The Development Of The High-power Short-pulse Laser Diode Driver

This paper discusses a high-power and narrow-width pulsed power supply of LD. Firstly, we introduce the development and characteristics of the LD. Secondly, we introduce the research status and the research significant of the LD's power supply. Thirdly, we analyse the operation principles and characteristics of the LD, and establish the scheme and technic path of designing the power supply of the narrow pulsed LD with high power. Then, we discuss the design scheme and component parameters selected of the circuits in detail which include the frequency measure circuit, low voltage DC, high voltage DC, high-power and high-peak nanosecond pulser and the trigger pulse controlled by the single chip microcomputer.At present, there are many kinds of switching components used in the power supply of the pulsed LD. We must choose the components basing on the type and using condition of the pulsed LD, when we design the power supply of the LD. After investigating, analysing the data and testing the circuit. A design scheme of the main cuicuit which can produce nanosecond pulse was choosed. This scheme was based on the use of avalanche transistors in a Marx Bank circuit. This nanosecond pulser was not as well as the universal one. We adopt two stage circuits. The firth stage uses a transistor which has a low avalanche voltage to narrow the trigger pulse. And then using the pulse which is obtained from this transistor to trigger the second stage circuit which is structured by a Marx Bank circuit.We can obtain a large and narrow current pulse which can be used to drive the LD. The trigger pulse of the nanosecond pulser is controlled by the single chip microcomputer. Therefore, it is facility to control the frequency of the output pulse.After fixing and debugging the LD's power supply. This power supply can produce a large-amplitude nanosecond pulse and its peak currents is up to 18.5A, pulse width is less than 5ns, maximal pulse repetition frequency is up to 100kHz. We meet the design requirements of the high-power and narrow-width pulsed LD's power supply.At last, we introduce software's design scheme and flow chart of the signal generator and the circuit measuring frequency. And detailedly analyse the data obtained from the experiment. It establishes the groundwork for successfully carrying out the next task.