Technique for writing of nonlinear optical single-crystal lines in glass

Abstract

The technique for the writing of crystal lines in glass by Nd:YAG laser irradiation, selective atom heat processing, is applied to rare-earth (Sm3+, Dy3+) barium borate glasses, and nonlinear optical β-BaB2O4 (β-BBO) crystal lines with a width of ∼5 μm are fabricated. The crystal lines show uniform colors in polarized optical microscope and second-harmonic generation (SHG) measurements. The azimuthal dependence of SHG signals in the crystal lines is the same as that in commercially available β-BBO bulk single crystals. It is demonstrated that the crystal lines written by YAG laser irradiations are β-BBO single crystals with the c-axis orientation along the laser scanning direction.

Nucleation and Crystal Growth in Laser-Patterned Lines in Glasses

“…The effective second-order nonlinear optical coefficient, deff, is given by the equation of deff = d22cos 2 θ. It was confirmed that the SH intensity for the straight line shown in Figure 1 changes as a function of cos 2 θ, indicating that β-BBO crystals in the straight line are highly oriented and grow with the c-axis orientation along the laser scanning direction (e.g., Honma et al, 2003;Ogawa et al, 2013). The c-axis orientation of β-BBO crystals has been already proposed in the previous papers (e.g., Honma et al, 2003;Ogawa et al, 2013).…”

“…In this work, crossing lines of nonlinear optical β-BaB2O4 (β-BBO) crystal were patterned by laser irradiation in Sm2O3-BaO-B2O3 glasses, and nucleation and crystal growth behaviors at the crossing point were examined from polarized optical microscope (POM) observations. So far, the patterning of highly oriented crystal lines (not crossing lines) of β-BBO in some glasses has been realized (Honma et al, 2003;Suzuki et al, 2012Suzuki et al, , 2013Ogawa et al, 2013;Nishii et al, 2015), and thus, β-BBO crystal would be a good example for the study of nucleation and crystal growth in the laser-induced crystallization in glasses.…”

Micro-architecture of nonlinear optical Ba2TiGe2O8 crystal dots and lines on the surface of laser-induced crystallized glasses by chemical etching

“…Recently, crystal dots and lines consisting of nonlinear optical crystals such as b-BaB 2 O 4 , Ba 2 TiGe 2 O 8 , and (Sr,Ba)Nb 2 O 6 have been patterned on the glass surface by irradiations of lasers such as continuous wave (cw) Nd:YAG lasers with a wavelength of l = 1064 nm [6][7][8][9][10][11][12][13]. In those laser-induced crystallization techniques, irradiated lasers are absorbed by rare-earth (RE) ions such as Sm 3+ through f-f transitions or transition metal (TM) ions such as Cu 2+ through d-d transitions in glasses, and the laser energy absorbed by RE or TM ions is transferred to lattice vibrations through a non-radiative relaxation process (electron-phonon couplings).…”

Laser-induced crystal growth of nonlinear optical crystal on glass surface

“…Using REAH processing, we examined the patterning of crystalline dots or lines in various glasses. Especially, we reported the formation of single crystal lines consisting of nonlinear optical BiBO3 26) and β -BaB2O4 (β -BBO) 30) crystals in Sm2O3-Bi2O3-B2O3 and Sm2O3(Dy2O3)-BaO-B2O3 glasses. Furthermore, Ihara et al 29) have reported the writing of two-dimensional crystal curved or bending lines consisting of rare-earth ion doped BiBO3 crystals showing a second harmonic generation (SHG).…”