The 30th International Conference on Advanced Laser Technologies
N-P-1
ALT'23
Optical parametric oscillation in periodically poled single crystals
of titanyl-phosphate family
M. Chuvakova1, A. Akhmatkhanov1, A.A. Esin1, I.A. Kipenko1, V. Shur1, A. Boyko2'3, D. Kolker23 L. Isaenko3, S. Zhurkov3
1- School of Natural Sciences and Mathematics, Ural Federal University, 620000 Ekaterinburg, Russia 2- Institute of Laser Physics SB RAS, 630090 Novosibirsk, Russia 3- Novosibirsk State University, 630090 Novosibirsk, Russia
E-mail: m.a.chuvakova@urfu.ru
Potassium titanyl phosphate Rb:KTiOPO4 (RKTP), potassium titanyl arsenate KTiOAsO4 (KTA) and rubidium titanyl arsenate RbTiOAsO4 (RTA) single crystals with periodical ferroelectric domain structure are one of the promising materials for nonlinear optical applications [1]. Despite the crucial importance of the in situ imaging of domain structure kinetics for creation of high quality periodical domain gratings, there are only a few works concerning potassium titanyl phosphate family.
We present the results of in situ imaging of domain kinetics in RKTP, KTA and RTA with the time resolution down to 12.5 ^s. The wide range of wall velocities with two orders of magnitude difference was observed for switching in a uniform electric field [2]. The kinetic maps allowed analyzing the spatial distribution of wall motion velocities and classifying the walls by velocity. The distinguished slow, fast, and superfast domain walls differed by their orientation. The mobility and the threshold fields for all domain walls were estimated [3]. The revealed increase in the wall velocity with deviation from low-index crystallographic planes for slow and fast walls was considered in terms of determined step generation and anisotropic kink motion.
The domain kinetics and switching fields in RKTP and KTA were compared. It was shown that the more pronounced input of slow domain walls in KTA results in creation of narrow stripe domains important for periodical poling [4,5]. Spontaneous backswitching was revealed in RTA single crystals. It was shown that the time interval from the end of switching pulse to the start of spontaneous backswitching process ("domain structure stability time") is proportional to the field applied during polarization reversal process. The periodical domain structure with period of 40 ^m was created in 3-mm-thick RKTP single crystals for OPO generation at 2.326 ^m using the 1.064 ^m pulsed pump with 5.6 ns duration at 20 Hz. The single resonance double-pass optical scheme was used. The threshold power energy 630 ^J and generation efficiency 7% were obtained.
We investigated the characteristics of a PPKTA OPO with a period of 39.2 ^m in the low-temperature-grown KTA sample. Under pumping at 1.053 ^m, the signal and idler wavelengths were, 1.54 and 3.31 ^m, respectively. The parametric generation threshold turned out to be 130 ^J (for a pump intensity of 14.4 MW cm-2), the quantum efficiency was 27%, and the differential efficiency was 12 % [6].
The obtained knowledge is important for further development of domain engineering in crystals of KTP family required for creation of high power, reliable, and effective coherent light sources.
The research was made possible by Russian Science Foundation (Grant No. 19-12-00210).
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[2] V. Ya. Shur, E. M. Vaskina, E. V. Pelegova, M. A. Chuvakova, A. R. Akhmatkhanov, O. V. Kizko, M. Ivanov, and A. L. Kholkin, Domain wall orientation and domain shape in KTiOPO4 crystals, Appl. Phys. Lett. vol.109, p. 132901, (2016).
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[6] L.I. Isaenko, A.P. Eliseev, D.B. Kolker, V.N. Vedenyapin, S.A. Zhurkov, E.Yu. Erushin, N.Yu. Kostyukova, A.A. Boiko, V.Ya. Shur, A.R. Akhmatkhanov, M.A. Chuvakova, Influence of growth temperature of KTiOAsO4 single crystals on their physicochemical parameters and formation of domain structures, Quantum Electronics, vol.50(8), pp.788-792, (2020).