Laser Deposited Epitaxial Oxide Heterostructures as Prototype Ferroelectric Optical Waveguides

1992 ◽  
Vol 285 ◽  
Author(s):  
D. K. Fork ◽  
G. B. Anderson
Keyword(s):  
Lithium Niobate ◽  
Optical Waveguides ◽  
Pulsed Laser ◽  
Frequency Doubling ◽  
Deposition Process ◽  
Electro Optic ◽  
Out Of Plane ◽  
Recent Developments ◽  
Laser Sources ◽  
Epitaxial Oxide

ABSTRACTThe pulsed laser deposition process is a powerful tool for investigating prototype epitaxial structures. This report outlines recent developments in epitaxial structures which may usefully serve as ferroelectric optical waveguides. Emphasis is given to structures on semiconductor substrates, motivated by hybrid optical/semiconductor integration. Earlier pulsed laser deposited structures, such as BaTiO3/MgO/GaAs (100) are discussed in conjunction with current results on Z-lithium niobate on GaAs (111)A and GaAs (111)B. BaTiO3/MgO/GaAs (100) grows with cube-on-cube crystallography. The epitaxial system z-lithium niobate on GaAs (111)A and GaAs (111)B has been demonstrated both with and without intermediate MgO (111) layers. The in-plane epitaxial relationships are LiNbO3 [110] // GaAs [211] and [211] indicating the existence of 180° boundaries in the LiNbO3 with and without the MgO layer, which grows cube-on-cube with the GaAs. Out-of-plane texture is typically 1.0° and 1.2° for the MgO and LiNbO3 layers respectively. In-plane texture is typically 2.8° and 4.5° for MgO and LiNbO3 layers respectively. These and similar epitaxial systems may be useful for monolithic electro-optic or frequency doubling applications in conjunction with semiconductor laser sources.

scholarly journals A Broadband High-Diffraction-Efficiency Electro-Optic Bragg Deflector Based on Monolithic Dual-Grating Periodically-Poled Lithium Niobate

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 242
Author(s):  
An-Chung Chiang ◽  
Yuan-Yao Lin ◽  
Shou-Tai Lin ◽  
Yen-Yin Lin
Keyword(s):  
Lithium Niobate ◽  
Wave Theory ◽  
Beam Radius ◽  
Acceptance Angle ◽  
Periodically Poled ◽  
Periodically Poled Lithium Niobate ◽  
Electro Optic ◽  
Recent Developments ◽  
Strong Focusing ◽  
Grating Design

Electro-optic (EO) Bragg deflectors have been extensively used in a variety of applications. Recent developments show that bandwidths and deflection efficiencies, as well as angular bandwidths, would significantly limit the utilization of EO Bragg deflectors, especially for applications which need strong focusing, such as intra-cavity applications. In this paper, we introduce a broadband EO Bragg deflector based on periodically-poled lithium niobate with a monolithic dual-grating design. We analyzed the deflection properties of this device by using a modified coupled wave theory and showed that this device can be still efficient for a small beam radius under strong focusing, whereas a single-grating one becomes very inefficient. Using a 1064-nm laser beam with a 100-μm beam radius, we obtained a 74% deflection efficiency with a 190-V bias voltage with a 0.5-mm-thick and 7.5-mm-long dual-grating sample. The acceptance angle for the Bragg condition of this device is as large as a few tens of mrad. The potential bandwidth of this device exceeds 500 nm if the proper operation region is chosen.

Laser-Assisted Etching of Lithium Niobate

1988 ◽  
Vol 126 ◽  
Author(s):  
Glennis J. Orloff ◽  
Steven L. Bernasek ◽  
Gary L. Wolk ◽  
R. J. Coyle
Keyword(s):  
Experimental Data ◽  
Chemical Analysis ◽  
Lithium Niobate ◽  
Rate Equation ◽  
Electron Spectroscopy ◽  
Optical Waveguides ◽  
Etch Rate ◽  
Auger Electron ◽  
Important Process ◽  
Electro Optic

ABSTRACTLaser-assisted dry etching of lithium niobate, LiNbO3, as well as other electro-optic materials could be an industrially important process in the fabrication of optical waveguides. In this investigation, an excimer laser (ArF; 193nm) was used to conduct etching reactions using nitrogen trifluoride, NF3. Enhancement of etching was observed by comparing the etch rate for a gas assisted process with that of a purely photoablative process. Chemical analysis of the etched features via Auger electron spectroscopy and correlation of a simple rate equation with the experimental data revealed that lasersurface interactions are responsible for the laser-assisted etching process.

Epitaxially induced secondary grain growth in Ti:LiNbO3 optical waveguides

1989 ◽  
Vol 47 ◽  
pp. 424-425
Author(s):  
M. A. McCoy
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Refractive Index ◽  
Lithium Niobate ◽  
Grain Growth ◽  
Optical Waveguides ◽  
Waveguide Devices ◽  
Transmission Electron ◽  
Electro Optic

Lithium niobate (LiNbO3) is one of the most promising materials for use in hybrid optical waveguide devices because of its high electro-optic coefficient and its availability as large single crystals. Optical waveguides in LiNbO3 are most commonly made by Ti indiffusion in which strips of Ti metal (between 10 and 100 nm thick) are deposited on a single crystal LiNbO3 substrate. The device is then heated to temperatures around 1000°C typically for 6 hours. During this time, the Ti diffuses into the LiNbO3 to form a Ti-rich LiNbO3 solid solution. This solid solution has a higher refractive index than the substrate and forms the waveguide region. Factors controlling the indiffusion process, however, are not very well understood and very little is known about the microstructural changes which occur during Ti indiffusion. In this study, the microstructure of Ti:LiNbO3 optical waveguides was examined as a function of time and temperature using transmission electron microscopy (TEM).

Progress Toward Viable Epitaxial Oxide Ferroelectric Waveguide Heterostructures on Gaas

1993 ◽  
Vol 310 ◽  
Author(s):  
D. K. Fork ◽  
J. J. Kingston ◽  
G. B. Anderson ◽  
E. J. Tarsa ◽  
J. S. Speck
Keyword(s):  
Lithium Niobate ◽  
Optical Waveguides ◽  
Critical Issue ◽  
Oxide Heterostructures ◽  
Thermally Induced ◽  
Cladding Layer ◽  
Gaas Substrates ◽  
Novel Approach ◽  
Waveguide Fabrication ◽  
Epitaxial Oxide

AbstractDiscoveries within the last two years have created possibilities for the fabrication of epitaxial oxide heterostructures on GaAs substrates. In particular, magnesium oxide, MgO, may have broad applications, including its use as a cladding layer in optical waveguides. This report expands upon earlier work by revealing additional epitaxial structures involving lithium niobate which have been grown. There are now five known variants of Z-lithium niobate on GaAs: direct Z-cut growth on GaAs (111)A or B, Z-cut growth on MgO (111)/GaAs (111)A or B, and Z-cut growth on MgO (111)/GaAs (001). Broad in-plane misalignment (about 15°) characterizes the latter structure, whereas the former posses a textural width of 3° to 5° in the plane. All structures contain internal boundaries resulting from 180° rotations about the Zaxis. A critical issue for any ferroelectric heterostructure is its integrity in the presence of thermally induced tensile strain. Approaches to the mitigation of thin fim fracture are discussed and a novel approach to strain relief via ridge waveguide fabrication is reported.

scholarly journals An Integrated Photonic Electric-Field Sensor Utilizing a 1 × 2 YBB Mach-Zehnder Interferometric Modulator with a Titanium-Diffused Lithium Niobate Waveguide and a Dipole Patch Antenna

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 459 ◽  
Author(s):  
Jung
Keyword(s):  
Lithium Niobate ◽  
Electric Field ◽  
Optical Waveguides ◽  
Extinction Ratio ◽  
Rf Power ◽  
Applied Electric Field Strength ◽  
Electric Field Sensors ◽  
Electric Field Sensor ◽  
Electro Optic ◽  
Field Sensor

We studied photonic electric-field sensors using a 1 × 2 YBB-MZI modulator composed of two complementary outputs and a 3 dB directional coupler based on the electro-optic effect and titanium diffused lithium–niobate optical waveguides. The measured DC switching voltage and extinction ratio at the wavelength 1.3 μm were ~16.6 V and ~14.7 dB, respectively. The minimum detectable fields were ~1.12 V/m and ~3.3 V/m, corresponding to the ~22 dB and ~18 dB dynamic ranges of ~10 MHz and 50 MHz, respectively, for an rf power of 20 dBm. The sensor shows an almost linear response to the applied electric-field strength within the range of 0.29 V/m to 29.8 V/m.

Nickel-Indiffusion Waveguide for TE-TM Mode Splitter in Lithium Niobate

1997 ◽  
Vol 08 (04) ◽  
pp. 621-642 ◽  
Author(s):  
Way-Seen Wang ◽  
Yu-Pin Liao ◽  
Chih-Hua Yang
Keyword(s):  
Lithium Niobate ◽  
Optical Waveguides ◽  
Propagation Loss ◽  
Dispersion Process ◽  
Tm Mode ◽  
Electro Optic ◽  
Dependent Polarization ◽  
First Time ◽  
Mode Splitter ◽  
Versus Concentration

Optical waveguides fabricated by nickel indiffusion on lithium niobate are reviewed. In particular, the fabrication process, index change versus concentration, wavelength dispersion, process-dependent polarization, propagation loss, and electro-optic modulation of the nickel indiffusion waveguide are discussed. To improve the confinement of single-ordinary polarization waveguide fabricated by nickel indiffusion, a novel waveguide made by zinc and nickel indiffusion is presented for the first time. Though the measured propagation loss of the waveguide is larger, the measured output power contours are found more symmetric. Moreover, several TE-TM mode splitters using one or more nickel indiffusion waveguides for the complete mode sorting effect are discussed.

scholarly journals Enhancement of piezoelectric properties of lithium niobate thin films by different annealing parameters

2020 ◽  
Vol 6 (2) ◽  
pp. 47-52
Author(s):  
Roman N. Zhukov ◽  
K.S. Kushnerev ◽  
Dmitry A. Kiselev ◽  
Tatiana S. Ilina ◽  
Ilya V. Kubasov ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Silicon Substrate ◽  
Optical Waveguides ◽  
Piezoelectric Materials ◽  
Random Access ◽  
Piezoelectric Phase ◽  
Electro Optic ◽  
Wide Range ◽  
Probe Microscope ◽  
Ferroelectric Random Access Memories

Piezoelectric materials with useful properties find a wide range of applications including opto- and acousto- electronics. Lithium niobate in the form of a thin film is one of those promising materials and has a potential to improve ferroelectric random access memories devices, optical waveguides or acoustic delay lines by virtue of its physical characteristics, e.g. electro-optic coefficient, acoustic velocity, refractive indices etc. The key challenge to overcome is lithium nonstoichiometry as it leads to the appearance of parasite phases and thus aggravates physical and structural properties of a film. According to literature data, in order to obtain microcrystalline piezoelectric phase in previously amorphous films a set of methods is used. In our case we tried to synthesize LN films using congruent target and non-heated silicon substrate and then attain the piezoelectric phase by different annealing parameters. Afterwards LN films were compared to the ones synthesized on the silicon substrate with an additional buffer layer of platinum. Samples were studied by scanning probe microscope. Self-polarization vectors were defined. Based on domain structure images, the histograms of distribution of piezoresponse signals were built.

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