• Current Optics and Photonics
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• v.6 no.3
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• pp.323-331
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• 2022

Electro-optic modulator (EOM) takes a vital role in connecting the electric and optical fields. Here, we present a heterogeneously integrated EOM based on the lithium niobate-on-insulator (LNOI) platform. The key modulation waveguide structure is a field-enhanced slot waveguide formed by embedding silicon nanowires in a thin-film lithium niobate (LN), which is different from the previously reported LN ridge or etchless LN waveguides. Based on such slot structure, optical mode field area is reduced and enhanced electric field in the slot region can interact well with LN material with high Electro-optic (EO) coefficient. Therefore, the improvements in both aspects have positive effects on enhancing the modulation performance. From results, the corresponding EOM by adding such modulation waveguide structure achieves better performance, where the key half-wave-voltage-length product (V_𝜋L) and 3 dB EO bandwidth are 1.78 V·cm and 40 GHz under the electrode gap width of only 6 ㎛, respectively. Moreover, Lower V_𝜋L can also be achieved. With these characteristics, such field-enhanced waveguide structure could further promote the development of LNOI-based EOM.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.135-138
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• 1997

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.397-398
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• 2005

Ferroelectric Lithium niobate ($LiNbO_3$) thin films are fabricated on $Al_2O_3$(0001) substrate using Pulsed Laser Deposition (PLD). The various deposition conditions such as substrate temperature, oxygen pressure, and post annealing condition are investigated to deposite c-axis oriented $LiNbO_3$ thin films. Highly c-axis oriented thin films are obtained under the conditions of working pressure of 100 mTorr, deposition for 10 min at $450^{\circ}C$, and in-situ annealing for 40 min. The $LiNbO_3$ thin films are chemically etched after electric poling and the etched configurations are studied by scanning electron microscope (SEM).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.1
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• pp.27-30
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• 2002

ZnO co-doped Er:$LiNbO_3$ single crystal thin films have been grown on $LiNbO_3$ (001) substrate by liquid phase epitaxy (LPE) method. The melts of ZnO co-doped Er:$LiNbO_3$ was fixed $Er_2O_3$, concentration (1 mol%) and different ZnO concentrations 3 and 5 mol%. The crystallinity of ZnO co-doped Er :$LiNbO_3$ films became better than the $LiNbO_3$ substrate. At ZnO 5 mol% concentration, the surface of ZnO co-doped Er:$LiNbO_3$ film is affected by compressive stress along both the perpendicular and the parallel direction. Also the surface of ZnO 3 mol% co-doped Er:$LiNbO_3$film is smoother than the original $LiNbO_3$ substrate surface.