Diode-pumped neodymium lasers repetitively Q-switched by Cr/sup 4+/:YAG solid-state saturable absorbers

Abstract

We report on the experimental results of a continuously diode-laser pumped Nd:YAG laser, operating at 1064 nm and repetitively Q-switched by a Cr 4+ :YAG solid-state saturable absorber. End-pumping the Nd:YAG with a 10-W fiber-coupled diode-laser we could either optimize the energy or the average output power, depending on the choice of the saturable absorber and the output coupler. The maximum energy was 200 J in single TEM00, 17 ns pulses at 6 kHz, whereas a maximum average power of 2 W with 32-ns pulses at 20 kHz was obtained. We also present preliminary results of a repetitively Qswitched Nd:YVO4 laser at 1064 nm. The repetitive Q-switching operation is described by an improved model, which accounts for the behavior of both the active medium and the solid-state saturable absorber. The results of the model agree fairly well with the experimental data. Experimental results of second harmonic conversion are also reported and interpreted using a depleted pump model.

The characteristics of the passively Q-switched Nd:YAG laser output energy with the initial absorbing effect of Cr4+:YAG absorber

“…YAG¢ ÒÏ 1 µm 2Ë &~ Nd:YAG, [1][2][3][4][5][6][7][8][9][10] Yb:YAG, [9] Nd:YVO 4 , [10,11] Ò Nd:Glass [12,13] .&ö & ÂKßW " Cr 4+ :YAG~ zßWö & & Ö B~² Úae ®. [14][15][16][17][18][19] >ÿ vÊ* .&~ ÂKßWf êṼ ²w" z>Ú~ zßWö ~.…”

“…r, ;WB &ê>*>º êV~ 7 ¶ 6² ' .V >*&ê > Ô² ;W> ÂKö.aeê V >ÿ vÊ* 8 ·² ¾aeÂ. V >ÿ vÊ* .& ÂKßW öBº ¸f Q-ç öB ¾ae¾º z>Ú~ Vç >f [4,12,[20][21] V& ç ®z *ç [1,2] " ¢~>î. $, v Ê* *ö B~º .&î~ ;7;ê¢ G;~ Ëÿ vÊ* â*j ;~ae .&~ ÎvÂK n;z¢ ËçÊ º ê& Úr.…”

“…"Úê. [4,12,[20][21][22] (1) r, t r f êVÚ 7 ¶ { ê¯*, σº .&î FêO ', nf B* >*&ê, lf .&î , Rf ÂKã >ÒN, Lf ;çÎ êV~ Ú¦ 7 ¶ , l s º z>Ú~ vþ. σ gs f σ es º z>ÚṼ &ç 5 Vç >'.…”

“…V¢B, 4&* Nd:YAG .&îöB >ÿ vÊ* .& Bj * & ²wö.ae E in ö & .&î ²wB >*&ê> n pi~ jº ;çÎ~ ^W ²wö. ae E th ö & ^W >*&ê> n th~ jf ?bae (4) f ? R* F > ®.…”

“…Ôf Q-çöB 7> Î"¢ J (4) ² >*&ê>º (5) :YAG~ R"êf V&ç >N &êç ßW. Ö'b, ¸f Q-çöB ¾ae¾º Vç >(excited state absorption), [4,13,15] V&ç~ ® z [2] '>, *Ï", fÒV, "zW>Ú Cr …”