High aspect ratio lithium niobate ridge waveguides fabricated by optical grade dicing

We report the development of a quick process for fabricating lithium niobate ridge waveguides with smooth walls, aspect ratios larger than 500 and side-wall verticality of 88?. The method is based on optical grade dicing, and allows the fabrication of ridges with a top width of 1??m and a depth of more than 500??m. Smart-cut ridge waveguides and strongly confined proton exchanged ridge waveguides are demonstrated. We show that the method enables the fabrication of ridge waveguides with propagation losses as low as 0.5?dB?cm?1. A new fabrication process is thus proposed for the fabrication of optical components with enhanced acousto-optic, electro-optic or nonlinear interactions. The high aspect ratios open opportunities towards the development of 3D photonic components in thin films of LiNbO3, and towards hybrid integration of LiNbO3 components.

[1]  Feng-Lei Hong,et al.  Efficient 494 mW sum-frequency generation of sodium resonance radiation at 589 nm by using a periodically poled Zn:LiNbO3 ridge waveguide. , 2009, Optics express.

[2]  Fabrication method of low-loss large single mode ridge Ti:LiNbO3 waveguides , 2007 .

[3]  P. Günter,et al.  Ion-sliced lithium niobate thin films for active photonic devices , 2009 .

[4]  H. Miyazawa,et al.  A broadband Ti:LiNbO/sub 3/ optical modulator with a ridge structure , 1995 .

[5]  S. Benchabane,et al.  LiNbO3 acousto-optical and electro-optical micromodulators , 2008 .

[6]  F. Devaux,et al.  Polarization and configuration dependence of beam self-focusing in photorefractive LiNbO 3 , 2009 .

[7]  D. Buchter,et al.  Lithium niobate photonic wires , 2009, 2010 IEEE Photinic Society's 23rd Annual Meeting.

[8]  Optical ridge waveguides preserving the thermo-optic features in LiNbO3 crystals fabricated by combination of proton implantation and selective wet etching. , 2010, Optics express.

[9]  Hiroshi Haga,et al.  LiNbO 3 traveling-wave light modulator/switch with an etched groove , 1986 .

[10]  N. Mitsugi,et al.  Growth of crystalline LiF on CF4 plasma etched LiNbO3 substrates , 1998 .

[11]  A. Bettiol,et al.  Suspended slab and photonic crystal waveguides in lithium niobate , 2010 .

[12]  Siyuan Yu,et al.  Etching characteristics of LiNbO3 in reactive ion etching and inductively coupled plasma , 2008 .

[13]  I. Barry,et al.  Ridge waveguides in lithium niobate fabricated by differential etching following spatially selective domain inversion , 1999 .

[14]  Ivan P. Kaminow,et al.  Lithium niobate ridge waveguide modulator , 1974 .

[15]  F. Baida,et al.  Analysis of a photonic crystal cavity based on absorbent layer for sensing applications , 2010 .

[16]  Fredrik Laurell,et al.  Wet etching of proton-exchanged lithium niobate—a novel processing technique , 1991 .

[17]  Huiying Hu,et al.  Plasma etching of proton-exchanged lithium niobate , 2006 .

[18]  Sorin Cristoloveanu,et al.  Frontiers of silicon-on-insulator , 2003 .

[19]  Raimund Ricken,et al.  Low-loss ridge waveguides on lithium niobate fabricated by local diffusion doping with titanium , 2010 .

[20]  K. Nelson,et al.  Fabrication of polaritonic structures in LiNbO3 and LiTaO3 using femtosecond laser machining , 2006 .