3-D analysis of LiNbO₃: Ti channel waveguides and directional couplers

Voltage-Length Product of X and Z-Cut Ti: LiNbO3 Directional Coupler and BOA Switches: A Comparison

“…and Φ(ζ'; h, g) is given by (15) but with mutually interchanged g and h. (The correct expression (16) is by a factor of two larger than that in [9].) We show in the next paragraph that the switching voltage of the X-cut BOA switch may be reduced by the fourelectrode structure sketched in the insert of Fig.…”

“…For the depth distribution, the approximate explicit expressions of [14] have been used. The lateral distribution of both modes in channel and double-channel waveguides have been numerically computed by the rigorous method of transversal resonance as described in [15].…”

Fabrication techniques of lithium niobate waveguides

“…While similar values of activation energy are reported in the literature, quite different values of diffusion coefficients have been published, depending on the crystal composition. The diffusion coefficient and the activation energy for crystals having a congruent composition (48.6 mole % Li 2 O), at 1050°C is 1.1 x 10" 1 2 cm 2 /s for all crystal orientations, and 2.2 eV, respectively [12,13].…”

Simulation of refractive index profiles for titanium indiffused lithium niobate channel waveguides

“…Let Ano and Ane be the changes of ordinary and extraordinary refractive indices, respectively, after Ti in-diffusion at a transmitting wavelength A. The relationships between the Ti-concentration C ( x , z ) and the induced refractive index changes Ano and An, that have been considered by different groups of researchers [4][5][6][7][11][12][13] are not consistent. Some of them of Ti atoms in the LiNbO, substrate is attributed to photoelasticity [16], the defects introduced by Ti-diffusion [17], and the strain induced by the diffusion of Ti into substitutional sites of LiNbO, [16].…”

“…Also, the relations between the Ti-concentration and the Ti-induced refractive index change considered by different groups are not consistent. Different groups of researchers [4][5][6][7][11][12][13] have used different values of coefficients and/or different functional relations between the Ti-concentration and the refractive index change to match their experimental conditions and data.…”