LiNbO3 Transducers

 

One of the most important components for acousto-optic devices is piezoelectric transducer converting electrical signal into the ultrasonic wave - crystal atomic lattice deformation.

 

 

Among many known crystals LiNbO3 (Lithium Noibate) crystals are used for AO devices based on TeO2. Lithium Noibate crystal has acoustic anisotropy and different shears generates different acoustic wave types. Two LiNbO3 orientation exhibit large piezoelectric coupling, the yz plane orientation and the xy plane orientation. Figure shows the piezoelectric coupling of LiNbO3  in the yz and xy plane. For longitudinal excitation, the 36˚ Y-cut orientation in the yz is preferred because no shear mode coupling is present. In this direction the longitudinal mode piezoelectric coupling constant is 0.49. Such shear is used for manufacturing of transducers based on TeO2 with sound propagation in (001). For shear mode excitation, either the 163˚ Y-cut orientation in the yz plane or an X-cut orientation in the xy plane is preferred. The X-cut orientation is usually used to excite shear waves in deflector devices because it has a higher shear mode coupling constant (0.48 versus 0.36), it excites a pure mode and there is no coupling to the quasilongitudinal mode. There is, however, coupling to the orthogonal shear mode. In those cases where orthogonal shear mode coupling must be suppressed, the 163˚ Y-cut orientation in the yz plane is used.

 

 

We supply following blanks for transducers:

Longitudinal:

36˚ Y-cut orientation

Shear:

163˚ Y-cut orientation

X-cut 41˚ orientation

as a wafer with thickness 1-2 mm and sizes up to 50х50 mm.

Surfaces can be grinded as well as one side polished and one electrode coated (typically Cr-Au).

 

Reference list:

[1] Xu J and Stroud R 1992 Acousto-Optic Devices (New York:Wiley)

[2] Handbook of optics. CHAPTER 12 ACOUSTO-OPTIC DEVICES AND APPLICATIONS I. C. Chang

[3] Goutzoulis A and Pape D 1994 Design and Fabrication of Acousto-Optic Devices (New York: Dekker)

Events/News

14th - 16th March 2017 - visit us at "Laser World of Photonics China 2017" fair in Shanghai, China. Hall 1 Booth 1735.

22 - 25 June 2015

June 2015 - visit us at "Laser World of Photonics 2015" fair in Munich, Germany.

Booth B1.439.

 

January 2015 - new edition of OptoIndex catalogue was published. You can find our company page here.