Phase transformation under direct laser writing in a YAG single crystal

Abstract

The transformation from Y 3 Al 5 O 12 to perovskite YAlO 3 crystal phase was observed during ultrafast laser writing in the bulk of a Y 3 Al 5 O 12 single crystal. The control of the phase transformation was demonstrated by tuning parameters of laser writing. The phenomenon is interpreted in terms of structural changes in the overheated garnet melt under laser heating followed by rapid solidification, and at least 1-ms dwell time of overheated melt is required to start spontaneous crystallization. The appearance of the perovskite phase was confirmed by Raman spectroscopy, quantitative phase and polarization microscopies.

Stress-induced optical waveguides written by an ultrafast laser in Nd3+, Y3+ co-doped SrF2 crystals

“…Within the last years, there are many reported results of stress-induced birefringence that was observed in transparent bulk materials namely YAG, Nd 3+ : YAG and LiNbO 3 crystals, borosilicate glass (BK7), doped phosphate and tellurite oxide, where seemingly the cohesion energy of the bonding strength play a vital role [23,26]. Polarimetric techniques are applied to compute birefringence's that are arisen by the not only stress, but also potentially through noncubic phase transformation to new formation of crystalline phase in the YAG waveguides under ultrafast laser irradiation [5].…”

“…In particular, these nanogratings, hitherto, are observed inside volume of a few specialized optical materials merely [1,2]. On the contrary, the stress-induced birefringent waveguides (no nanogratings) are observed in bulk transparent materials, which is arisen by the coupling of elasto-optical and the mechanical stress induced at vicinity of the laser track [1][2][3][4][5][6]26]. Noticeably, the high symmetric fabricated type-II waveguides inside materials can preserve non-destructive material properties and high resistance by so called "double line" technique [7][8][9].…”

“…Fs laser driven self-organized nanostructures and nanovoids initially observed in fused silica related structural and optical properties that is studied extensively over one decade ago [1,2]. Subsequently, these sort of nanostructures are commonly known as "Nanogratings" consisting of sheet like cavities with a sub-wavelength periodicity and is successfully harnessed to scalable photonic applications including optofluidics and lab-on-a-chip devices [1][2][3][4][5][6]. In particular, these nanogratings, hitherto, are observed inside volume of a few specialized optical materials merely [1,2].…”

Feature issue introduction: shaping and patterning crystals for optics

“…The phenomenon is interpreted in terms of structural changes in the overheated garnet melt under laser heating followed by rapid solidification, and at least 1-ms dwell time of overheated melt is required to start spontaneous crystallization. The appearance of the perovskite phase was confirmed by Raman spectroscopy, quantitative phase and polarization microscopies [4].…”

“…The average output power reached 1.13 W [3]. The transformation from Y 3 Al 5 O 12 to perovskite YAlO 3 crystal phase was observed during ultrafast laser writing in the bulk of Y 3 Al 5 O 12 single crystal by Okhrimchuk et al [4]. The control of the phase transformation was demonstrated by tuning the parameters of laser writing.…”