Optical breakdown threshold in the electron-thermal model of defect generation

Laser-induced instability in transparent materials induced by low-absorbing microinclusion

“…The latter result is illustrated by graphs from [8] (Fig. 2.) and estimations in Table 1 obtained for typical values of wideband-gap material and radiation parameters.…”

“…Threshold laser fluence of LID q for all considered above models is determined by one and the same criterion (equality of initial and laser-induced absorption) and given by the following expression: q*(R)= U• Tiao.R1 (8) a(R)•R a(R)j where a(R) -absorption of microinclusion,, c -thermal conductivity of the host material, U -activation energy for corresponding model of feedback.…”

“…That model opened new direction for theoretical investigations and gave new possibilities for understanding of nature of LID. Recently the concept of LID initiating by instabilities was enriched by model of inclusion-induced field instability1 [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] In general case instability of a certain parameter A (temperature T in case of thermal instability and electric field strength E in case of field instability) induced by inclusion comes through the following" ''': either both the parameter A inside the inclusion and its derivation with respect to incident field amplitude E0 tends to infinity while incident field amplitude approaches finite threshold value E*o: ÔA * A-+cc, -+ciwith E -*E (1) 5E0 0 0 or the parameter tends to some limited value and its derivation tends to infinity:…”

Mechanism of self-focusing of laser pulses on dynamic lenses in transparent media

“…(iii) For the materials with a weak dependence of dn/dp on pressure (LiF) and superpure materials, the laser destruction threshold is apparently determined by an electronic-thermal mechanism of defect gener ation [28].…”