| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical modulator sufficiently independent of polarization by suppressing excessive diffusion of Ti in a direction horizontal to a crystal substrate surface and a method for manufacturing the same. <P>SOLUTION: The optical modulator is constructed by forming a Ti diffusion waveguide on the X cut surface of a LiNbO3 crystal substrate in the Z-axis direction of the LiNbO3 crystal substrate. In manufacturing an X cut Z propagating optical modulator, slits 5 to suppress the diffusion of a Ti film 10 in a horizontal direction are formed with etching between the Ti diffusion waveguide 3 and the LiNbO3 crystal substrate 2. Widths of the slits 5 are 0.1-3μm. Depths of the slits 5 are 5-10μm measured from the LiNbO3 crystal substrate surface. As a result, the slits 5 become separation parts and suppress the diffusion of Ti in the horizontal direction having diffusion speed of two times or more than that in the vertical direction of the LiNbO3 crystal. Consequently the X cut Z propagating optical modulator with no polarization dependency and the method for manufacturing the same are obtained. <P>COPYRIGHT: (C)2004,JPO</p> |
