Research On1.06μm Pulse Burst Laser Generation And Output Characteristics

There are urgent needs of laser pulse with high repetition frequency and highenergy in the field of laser diagnostic. But the conventional laser cannot output the twocharacters at the same time because of the limit of average power. So, this paperstudies the high repetition frequency and high energy laser: research on methods ofachieving pulse burst and pulse burst laser amplification, in order to get string of highrepetition frequency and energy pulses.Using rate equation theory, the paper analyzes the CW output of Nd:YVO4continuous four-level laser system end-pumped by LD and pulsed output charactersuch as peak power, pulse width, single pulse energy. The energy extraction efficiencyand the relationship of single signal pulse energy and the enlarged single pulse energyare deduced, as well as the single pulse energy and extraction efficiency at high ratepulse burst mode.The output characteristics of the pulse burst laser oscillator was researched. Firstly,the Nd:YVO4laser oscillator end-pumped by879nm CW LD was experimentallyresearched. A CW26.2W output was achieved with optical to optical conversionefficiency of53%, when the absorbed pump power was49.4W. In pulse operation,134.6kW、31.1kW and12.6kW peak power output was achieved corresponding to thepulse duration of7.8ns、12.0ns and17.2ns at repetition frequency of10kHz,50kHzand100kHz, respectively. The output pulse sequence was selected to pulse burstutilizing electro-optic modulation theory. And the parametric of the burst was flexiblyadjusted. We got pulse burst contain of10,50,100pulses at oscillation frequency10kHz,50kHz and100kHz, when the high voltage pulse width1ms. Then,808nmend-pumped Nd:YVO4Q-switched oscillator was studied. Single pulse energy of7.3mJ output was achieved at non-Q-switched with the LD output rate of10Hz, LDpulse width of1ms. At Q-switched mode, oscillator output pulse burst energy of6mJ、6.7mJ and6.9mJ corresponding to the pulse duration9.5ns，26.0ns and37.3ns at Q rateof10kHz,50kHz and100kHz, respectively. And the pulse burst contains of10,50and100pulses at the three Q-rates.The output pulse burst achieved by the method of pulsed pump Q-switched laserwas amplified. Passed through the amplifier, laser pulses with single pulse energy of6.4mJ,1.5mJ and0.7mJ are got at Q-rate of10kHz,50kHz and100kHz. Theperformance is superior to the conventional laser at the same conditions, which reflects the advantage of the pulse burst laser to the conventional laser. Pulse burst laser is aneffective method to achieve high repetition frequency and high energy laser pulse.