Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Characterization of near-stoichiometric Ti : Li Nb O 3 strip waveguides with varied substrate refractive index in the guiding layer

Not Accessible

Your library or personal account may give you access

Abstract

We have demonstrated the possibility that near-stoichiometric Ti:LiNbO3 strip waveguides are fabricated by carrying out vapor transport equilibration at 1060°C for 12h on a congruent LiNbO3 substrate with photolithographically patterned 48μm wide, 115nm thick Ti strips. Optical characterizations show that these waveguides are single mode at 1.5μm and show a waveguide loss of 1.3dBcm for TM mode and 1.1dBcm for TE mode. In the width/depth direction of the waveguide, the mode field follows the Gauss/Hermite–Gauss function. Secondary-ion-mass spectrometry (SIMS) was used to study Ti-concentration profiles in the depth direction and on the surface of the 6μm wide waveguide. The result shows that the Ti profile follows a sum of two error functions along the width direction and a complementary error function in the depth direction. The surface Ti concentration, 1e width and depth, and mean diffusivities along the width and depth directions of the guide are similar to 3.0×1021cm3, 3.8μm, 2.6μm, 0.30 and 0.14μm2h, respectively. Micro-Raman analysis was carried out on the waveguide endface to characterize the depth profile of Li composition in the guiding layer. The results show that the depth profile of Li composition also follows a complementary error function with a 1e depth of 3.64μm. The mean ([LiLi]+[TiLi])([NbNb]+[TiNb]) ratio in the waveguide layer is about 0.98. The inhomogeneous Li-composition profile results in a varied substrate index in the guiding layer. A two-dimensional refractive index profile model in the waveguide is proposed by taking into consideration the varied substrate index and assuming linearity between Ti-induced index change and Ti concentration. The net waveguide surface index increments at 1545nm are 0.0114 and 0.0212 for ordinary and extraordinary rays, respectively. Based upon the constructed index model, the fundamental mode field profile was calculated using the beam propagation method, and the mode sizes and effective index versus the Ti-strip width were calculated for three lower TM and TE modes using the variational method. An agreement between theory and experiment is obtained.

© 2008 Optical Society of America

Full Article  |  PDF Article
More Like This
Near-stoichiometric Ti:Sc:LiNbO3 strip waveguide for integrated optics

Xiao-Fei Yang, Zi-Bo Zhang, Wan-Ying Du, Qun Zhang, Wing-Han Wong, Dao-Yin Yu, Edwin Yue-Bun Pun, and De-Long Zhang
Opt. Mater. Express 6(8) 2637-2643 (2016)

Zirconium-diffusion-doped Ti:LiNbO3 strip waveguide for integrated optics

De-Long Zhang, Jian Kang, Qun Zhang, W. J. Du, W. H. Wong, and E. Y. B. Pun
Opt. Mater. Express 5(8) 1715-1721 (2015)

Near-stoichiometric Ti-diffused LiNbO3 strip waveguide doped with Zr4+

De-Long Zhang, Xiao-Fei Yang, Qun Zhang, Wing-Han Wong, Dao-Yin Yu, and Edwin Yue-Bun Pun
Opt. Lett. 40(22) 5307-5310 (2015)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (12)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (22)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved