Low-loss broad-band LiNbO₃guided-wave phase modulators using titanium/magnesium double diffusion method

<title>Improvement on coupling efficiency of dichroic and fiber amplifier by Ti/Mg double diffusion</title>

“…Furthermore, the bulk refractive index nb(,\) is found by the modified Sellmeier's equation. 8 With the information mentioned above, the whole refractive index profile of the Ti/Mg:LiNbO3 channel waveguide is given by n(y, z, ) = flTi(Y, z, A) + flMg(Y, Z, ) + nb() (2) Although, the Mg-induced refractive index change LnMg(y,z,\ ) can not be calculated directly, but it can be calculdted from both of the fractional index changes to the Mg concentration dn/dc and Sellmerier's equation. n2=A+2c_D2 (3) where n is the refractive index of LiNbO3 , the constants A, B, C, and D are referred from the published data.7 In addition, the approximation of LnT(y,z,A) can be obtained from the wavelength dispersion of Ti induced refractive index changes on the surface in the planner where /-'Ti iS the maximum refractive index changes on the surface, Bo(\)and B1 (A) are the dispersion factors, a is the constant coefficients6.…”

Integrated-optic devices in lithium niobate: technology and applications

“…Considerable progress has been made in fibre attachment technology during the last years with the result that total fibre-waguide-fibre insertion loss figures came down from typically 10 dB to about 2-3 dB. "Best case" results better than 1dB have been reported [10]. Furthermore, the stability of the fibre coupling against mechanical and thermal stress has been greatly improved.…”

Coherent Optical Communications

“…However, it requires not only a narrower spectral width of LDs, but usually an external phase modulator, which introduces more than a few dB insertion loss. Figure 10 shows a typical phase modulator of LiNbO3 Komatsu et al (5). Such a type of phase modulator 5-10 cm long can usually be modulated with 5-10 volt up to a few GHz.…”