On-wafer 2D electric-field-vector mapping using one-beam electro-optic probing technique

Summary form only given. Depending upon the space group of EO crystals and the applied electric-field vectors (E vector), the index ellipsoid of the EO crystal experiences compressed/stretched deformation or rotational deformation. Most conventional EO probing techniques only use compressed/stretched deformation modulation (CSDM), hence, two beams or two different EO crystals are required to differentiate the applied electric field directions. Consequently, the measurement becomes complicated and inaccurate. Now, we present the EO probing technique using single beam and single crystal to monitor the 2D electric field using rotational deformation modulation (RDM), a newly developed modulation skill. Both CSDM and RDM techniques are adopted by our system to monitor the electric field vector. The measured results are in good agreement with the simulations obtained by a commercial "Ansoft Maxell 3-D Field Simulator". The experiment set-up is similar to our previous work on 2-beam E-vector measurement except that the He-Ne laser is replaced by a single longitudinal mode laser diode (wavelength = 635 nm), and the compensator is no longer needed for RDM. The beam path within the LiTaO/sub 3/ is presented.