Producing Mono2Pulse Laser of Nanosecond Burst2Length by Cutting2Apart from Q2Beam Self2Triggered

Transcription

1 C HIN ESE J OU RNAL O F L ASERS Vol. 34, No. 4 April, 2007 : (2007) Q 1, 2, 3 1, , ; 3, , Q KDP, 19 kv Q,, 30 ns, 80 mj Q 1. 7 ns,4 mj,, ; ; ; TN 242 ;O A Producing Mono2Pulse Laser of Nanosecond Burst2Length by Cutting2Apart from Q2Beam Self2Triggered DON G Xiao2gang 1, L I Liang2yu 2, YAN Si2xian 3 1 O ptoelect ronic L aboratory of A cadem y of A rmored Forces Engineering, The Chinese People s L iberation A rm y, B ei j ing , China 2 Cheng du M unici pal S cience and Technolog y B ureau, Cheng du, S ichuan , China 3 Modern A p plied Physics Department, Tsinghua Universit y, B ei j ing , China Abstract For obtaining simple mono2pulse laser of nanosecond burst2length and high peak power with available equipment s in order to satisfy time2resolved demands in something to do with military application and in interferometric research of high temperature plasma, the trigged gap of KDP Pockels cell for chopping Q2beam it self was optimized by using certain patent technique, the dilemmas of dual reliability as well as synchronism of whole system were overcome in both static electric2separating of the gap enduring at full2wave voltage (V ) of 19 kv and easily puncturing of the insulating film between gap s electrodes by the low f ront of Q2beam self2triggering, the high2speed triggering and the chopping near the peak of Q2beam were guaranteed, and a mono2pulse laser of 1. 7 ns burst2length with 4 mj pulse energy cut apart f rom Q2beam of a 30 ns/ 80 mj traditional ruby laser was realized. Experimental investigation and theoretical analysis indicate, the optimized pre2processing distorted the distribution of the electric field between gap s electrodes, strengthened the effect of the Q2beam s triggering, and ensured the chopped laser pulse with short duration and high power. Key words laser technique ; nanosecond mono2pulse laser ; self2triggered electro2optic switch ; high2voltage resistant film 1 Q,, : ; : : ( ) : (1962 ),,,,, E2mail com. cn

2 34 [ 1 ] [2 ], [3 ] KTP Q, [4 ] KD 3 P,, ( ) ( (DPF),Z ( Z2pinch) ) 10 ns [5 7 ], [ 8 ] ( ) Q [ 9 ],, Blumlein,,,, [10 ], KDP 0 19 kv KDP 19 kv,, Blumlein, 1. 7 ns KDP Q 180,, 90,, Q P2,, Q,, 10 GHz, 2,Blumlein KDP, m, KDP 19 kv ( m), 50 m 1 mm, KDP 0,,19 kv Q P2, 50 mm ( W/ mm 2 ),,, Blumlein KDP,, R0 Fig. 1 1 L TSG: Cutting2switch of nanosecond mono2pulse laser beam L TSG: laser triggered spark gap Blumlein,, Q [11,12 ], 1 m 3 2 Q, 30 ns, 80 mj, 2. 7 MW, W/ mm 2 3, 1. 7 ns 4, HP54512B, 4 466

3 4 : Q, Q,, 4 mj, (,,, ) 4 3 Fig. 3 Fig. 4 2 Fig. 2 Q Q2beam waveform Q Mono2pulse laser cut apart f rom Q2beam ( ) Q ( ) Relative time between the Q2beam ( upper) and the nanosecond pulse (lower),,,,,, Q,, Q,, Q 1) Q 80 mj ( ), MW, W/ mm 2, 80 mj Q Q, Q,, Q 0,,, Q 30 mj 1. 1 MW, W/ mm 2, Q 10 mj ( W/ mm 2 ) 0. 5 mj, ( ), Q 2) KDP 19 kv,,,, [13 ], KDP, 3) 50 m 19 kv 467

4 34 3 kv/ mm, ( ),, 10 kv, ;,,,,, Q,,,, 19 kv 4), Q, Q ;, KDP, Q ( 20 ns),, Q,,Blumlein L 3 m, Q 10 ns, Q 10 ns ( 0 ), Q,,,, 5,,, Q ( W/ mm 2 ) [10,12 ], 20 kv, Q 10 mj ( 5 (a) ; (b) ; (c) Fig. 5 Relative time between the Q2beam (upper) and the nanosecond pulse (lower) (a) electrolines distribution between gap s electrodes before the pre2processing ; ( b ) electrolines distribution after the pre2 processing ; ( c ) equipotential lines distribution after the pre2 processing W/ mm 2 ), 0. 5 mj 4 Q,,,,,,,, 1 Xu Faming, Chen Shaohe, Chen Lanrong et al.. Pulse chopping by fast2response electro2optic deflectors [J ]. Chinese J. Lasers, 1996, A23 (9) :

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