Evanescently coupled fs laser-written type II waveguide array in lithium niobate

We report the realization of an evanescently coupled laser-written type II array in χ-cut Lithium niobate. Certain processing parameters allow evanescent fields to extend beyond the regions of damage, while still increasing the index sufficiently to guide light. An array consisting of eleven coupled waveguides was fabricated. Coupling was evaluated by observing discrete diffraction patterns of single waveguide excitations at various array sites. Homogeneous coupling was verified within the array, while the outermost guides are slightly detuned due to being formed by just one damage structure.

[1]  F. Lederer,et al.  Observation of discrete quadratic solitons. , 2004, Physical review letters.

[2]  M. Fejer,et al.  Nonlinear directional coupler in periodically poled lithium niobate. , 1999, Optics letters.

[3]  Nan Ei Yu,et al.  Second-harmonic generation in periodically poled lithium niobate waveguides fabricated by femtosecond laser pulses , 2006 .

[4]  S. Nolte,et al.  Femtosecond waveguide writing: a new avenue to three-dimensional integrated optics , 2003 .

[5]  Andreas Tünnermann,et al.  Efficient frequency doubling in femtosecond laser-written waveguides in lithium niobate , 2006 .

[6]  Andreas Tünnermann,et al.  Structural properties of femtosecond laser-induced modifications in LiNbO3 , 2006 .

[7]  Alan L. Jones.  Coupling of Optical Fibers and Scattering in Fibers , 1965 .

[8]  J. Veselka,et al.  Proton exchange in LiNbO3 , 1983 .

[9]  A. Tünnermann,et al.  Evanescent coupling in arrays of type II femtosecond laser-written waveguides in bulk x-cut lithium niobate , 2008 .

[10]  Robert R. Thomson,et al.  Optical waveguide fabrication in z-cut lithium niobate (LiNbO3) using femtosecond pulses in the low repetition rate regime , 2006 .

[11]  Amir H Nejadmalayeri,et al.  Ultrafast laser waveguide writing: Lithium niobate and the role of circular polarization and picosecond pulse width. , 2006, Optics letters.

[12]  Andreas Tünnermann,et al.  Light evolution in arbitrary two-dimensional waveguide arrays , 2007 .

[13]  Roberta Ramponi,et al.  Femtosecond laser writing of waveguides in periodically poled lithium niobate preserving the nonlinear coefficient , 2007 .

[14]  Andreas Tünnermann,et al.  Femtosecond laser-written quasi-phase-matched waveguides in lithium niobate , 2007 .

[15]  Andreas Tünnermann,et al.  Waveguides in lithium niobate fabricated by focused ultrashort laser pulses , 2007 .

[16]  K. Miura,et al.  Writing waveguides in glass with a femtosecond laser. , 1996, Optics letters.

[17]  J. Noda.  Ti-Diffused LiNbO3 Waveguides and Modulators , 1980 .

[18]  Tow Chong Chong,et al.  Microstructure in lithium niobate by use of focused femtosecond laser pulses , 2004 .

[19]  S. Nolte,et al.  Hexagonal waveguide arrays written with fs-laser pulses , 2006 .