Advanced Ti-Implanted Optical Waveguides in LiNbO3

1986 ◽  
Vol 88 ◽  
Author(s):  
Ch. Buchal ◽  
P. R. Ashley ◽  
D. K. Thomas ◽  
B. R. Appleton
Keyword(s):  
Low Temperatures ◽  
Optical Waveguides ◽  
Crystalline State ◽  
Solid Phase ◽  
Equilibrium Phase ◽  
Planar Waveguides ◽  
Solid Phase Epitaxy ◽  
Low Loss ◽  
Versatile Technique ◽  
Channel Waveguides

ABSTRACTLiNbO3 is the best substrate for modulators and switches for integrated optics. Efficient low loss waveguides for light in LiNbO3 are formed by introducing Ti-ions into its lattice, thus increasing locally the ordinary and the extraordinary indices of refraction. We are the first to use the very versatile technique of ion-implantation to administer Ti into LiNbO3. This implantation process offers the possibility to introduce significantly more Ti into a well-defined volume than conventional diffusion techniques. During this process first an amorphous non-equilibrium phase is generated, which has to be kept at low temperatures in order to prevent segregation. Subsequent thermal treatment leads to solid phase epitaxy and restores the desired stable crystalline state. We have used this technique to fabricate excellent planar waveguides, channel waveguides and Mach-Zehnder modulators.

Optical Waveguide Formation by Ion Implantation of Ti or Ag

1988 ◽  
Vol 100 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas
Keyword(s):  
Ion Implantation ◽  
Concentration Profile ◽  
Optical Waveguides ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Effective Means ◽  
Complete Removal ◽  
Solid Phase Epitaxy ◽  
Annealing Temperatures ◽  
Residual Damage

ABSTRACTIon implantation of Ti into LINbO3 has been shown to be an effective means of producing optical waveguides, while maintaining better control over the resulting concentration profile of the dopant than can be achieved by in-diffusion. While undoped, amorphous LiNbO3 can be regrown by solid-phase epitaxy at 400°C with a regrowth velocity of 250 Å/min, the higher concentrations of Ti required to form a waveguide (∼10%) slow the regrowth considerably, so that temperatures approaching 800°C are used. Complete removal of residual damage requires annealing temperatures of 1000°C, not significantly lower than those used with in-diffusion. Solid phase epitaxy of Agimplanted LiNbO3, however, occurs at much lower temperatures. The regrowth is completed at 400°C, and annealing of all residual damage occurs at or below 800°C. Furthermore, the regrowth rate is independent of Ag concentration up to the highest dose implanted to date, 1 × 1017 Ag/cm2. The usefulness of Ag implantation for the formation of optical waveguides is limited, however, by the higher mobility of Ag at the annealing temperature, compared to Ti.

Integrated (Pb,La)(Zr,Ti)O3 Heterostructure Waveguide Devices Fabricated by Solid-Phase Epitaxy

1999 ◽  
Vol 597 ◽  
Author(s):  
K. Nashimoto ◽  
S. Nakamura ◽  
H. Moriyama ◽  
K. Haga ◽  
M. Watanabe ◽  
...  
Keyword(s):  
Low Voltage ◽  
Solid Phase ◽  
Wet Etching ◽  
Propagation Loss ◽  
Beam Deflection ◽  
Solid Phase Epitaxy ◽  
Te Mode ◽  
Tm Mode ◽  
Electro Optic ◽  
Channel Waveguides

AbstractHeterostructures of a Pb(Zr,Ti)O3 (PZT) waveguide/(Pb,La)(Zr,Ti)O3 (PLZT) system buffer layer were grown on a Nb-doped SrTiO3 (Nb:ST) substrate by solid-phase epitaxy. The propagation loss in the PLZT heterostructure waveguides was on the order of I dB/cm. An electro-optic beam deflection device with an ITO prism electrode on the surface of the PLZT heterostructure waveguide presented efficient deflection of the coupled laser beam by applying a voltage between the electrode and the substrate. A beam deflection greater than 10 mrad at 5 V and frequency response as fast as 13 MHz were observed. An apparent electro-optic coefficient as large as 39 pmJV was estimated from the deflection characteristics for the TE mode and TM mode suggesting the polarization independent nature of the PZT waveguide. For integrating the electrooptic PLZT heterostructure waveguides, channel waveguides were fabricated in the PZT waveguides using a simple wet-etching process. Based on a low-voltage drive structure, lowloss waveguide process, and fine patterning process, a fabricated digital matrix switch showed a – 10 dB cross-talk at a voltage as low as 7.5 V.

Novel Approach for Fabrication of Single-Crystalline Insulator/Si/Insulator Nanostructures

2006 ◽  
Vol 928 ◽  
Author(s):  
Andreas Fissel ◽  
Dirk Kuehne ◽  
Eberhard Bugiel ◽  
H. Joerg Osten
Keyword(s):  
Low Temperatures ◽  
Negative Differential Resistance ◽  
Molecular Beam ◽  
Solid Phase ◽  
Differential Resistance ◽  
Solid Phase Epitaxy ◽  
Double Barrier ◽  
Single Crystalline ◽  
Novel Approach ◽  
Sharp Interfaces

ABSTRACTDouble-barrier insulator/Si/insulator nanostructures on Si(111) were prepared using molecular beam epitaxy. Ultrathin single-crystalline Si buried in a single-crystalline insulator matrix with sharp interfaces was obtained by a novel approach based on an epitaxial encapsulated solid-phase epitaxy. As an example, we demonstrate the growth of Si buried in Gd2O3 and the incorporation of epitaxial Si islands into single-crystalline Gd2O3. The I-V characteristic of the obtained nanostructures exhibited negative differential resistance at low temperatures, however, with a strong memory effect.

Planar, low‐loss optical waveguides fabricated by solid‐phase regrowth

1992 ◽  
Vol 61 (11) ◽  
pp. 1269-1271 ◽  
Author(s):  
W. Xia ◽  
L. S. Yu ◽  
Z. F. Guan ◽  
S. A. Pappert ◽  
P. K. L. Yu ◽  
...  
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Low Loss ◽  
Solid Phase Regrowth

PZT Electro-Optic Waveguide Devices Fabricated by Solid-Phase Epitaxy

1997 ◽  
Vol 493 ◽  
Author(s):  
Keiichi Nashimoto ◽  
Shigetoshi Nakamura ◽  
Hiroaki Moriyama ◽  
Masao Watanabe ◽  
Eisuke Osakabe
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Solution Process ◽  
Propagation Loss ◽  
Metal Alkoxide ◽  
Solid Phase Epitaxy ◽  
Optical Propagation ◽  
Electro Optic ◽  
Pzt Thin Film ◽  
Conductive Substrate

ABSTRACTHigh quality epitaxial PZT optical waveguides have been grown by solid-phase epitaxy based on metal alkoxide solution process. Optical propagation loss was 4 dB/cm in epitaxial PZT thin film optical waveguides grown on SrTiO3 substrates. Epitaxial PZT optical waveguides were grown on Nb doped conductive SrTiO3 substrates, since considerable reduction in drive voltage will be expected when top electrode / optical waveguide / conductive substrate structures are realized. Propagation loss was relatively large, as compared with the structure using non-dope insulative substrates. Preliminary electrooptic deflection devices were fabricated by preparing prism electrodes on the surface of the PZT optical waveguides. Efficient deflection/switching of coupled laser beam in the PZT optical waveguides as large as 26 mrad was observed by applying 70 volts between prism electrode and Nb doped SrTiO3 substrates.

Solid-phase epitaxy of Ti-implanted LiNbO3

1989 ◽  
Vol 4 (2) ◽  
pp. 412-416 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Complete Removal ◽  
Amorphous Region ◽  
Liquid Nitrogen Temperature ◽  
High Dose ◽  
Solid Phase Epitaxy ◽  
Complete Recrystallization ◽  
Water Saturated ◽  
Saturated Oxygen

The solid-phase epitaxy of LiNbO3 following ion implantation of Ti dopant for the purpose of producing optical waveguides has been studied. Implanting 360-keV Ti at liquid nitrogen temperature produces a highly damaged region extending to a depth of about 400 nm. This essentially amorphous region can be recrystallized epitaxially by annealing in a water-saturated oxygen atmosphere at temperatures near 400 °C. though complete removal of all irradiation-induced damage requires temperatures in excess of 600 °C. The activation energy of the regrowth is 2.0 eV for implanted fluences below 3 ⊠ 1016 Ti/cm2. At higher fluences the regrowth proceeds more slowly, and Ti dopant segregates at the regrowth interface. Complete recrystallization following high-dose implantation requires annealing temperatures in excess of 800 °C.

Kinetic Competition During Solid Phase Crystallization in Ion–Implanted Silicon

1983 ◽  
Vol 23 ◽  
Author(s):  
G.L. Olson ◽  
J.A. Roth ◽  
L.D. Hess ◽  
J. Narayan
Keyword(s):  
Complex Formation ◽  
Low Temperatures ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Solid Phase Crystallization ◽  
Competing Interactions ◽  
Cross Sectional ◽  
Time Resolved ◽  
Vacancy Model ◽  
Dominant Process

ABSTRACTWe report on an investigation of the temperature and concentration dependent kinetic competition between solid phase epitaxy and complex formation and precipitation in arsenic–implanted Si(100). Crystallization kinetics were monitored using time–resolved reflectivity during cw laser irradiation or furnace heating; microstructural changes were evaluated using cross–sectional TEM. At low temperatures and high As concentrations, complex formation and precipitation substantially alter the SPE kinetics. At higher temperatures competing interactions are less significant, and SPE becomes the dominant process. The kinetic competition between these processes is discussed with respect to the vacancy model for SPE.

Solid-Phase Epitaxy with X-Ray Irradiation to Grow Dislocation-Free Silicon Films at Low Temperatures

1991 ◽  
Vol 30 (Part 2, No. 2A) ◽  
pp. L205-L208 ◽  
Author(s):  
Fumio Sato ◽  
Katsuyuki Goto ◽  
Jun-ichi Chikawa
Keyword(s):  
Low Temperatures ◽  
Solid Phase ◽  
Silicon Films ◽  
Solid Phase Epitaxy ◽  
X Ray ◽  
Free Silicon

Channeling Investigation of the Lattice Location of Ti in Ti-Implanted Optical Waveguides in LiNbO3

1988 ◽  
Vol 100 ◽  
Author(s):  
Ch. Buchal ◽  
S. Mantl ◽  
D. K. Thomas
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Lattice Location ◽  
Solid Phase Epitaxy ◽  
X Rays ◽  
Ion Channeling

ABSTRACTIon channeling of 3 MeV He ions has been employed to investigate the lattice location of Ti in Ti implanted optical waveguides in LiNbO3 after Solid Phase Epitaxy. Particle-Induced X-rays (PIXE) from Ti at 4.5 keY (K∝) and Nb at 2.2 keV (L∝β) and 16.6 keV (K∝) have been detected and analyzed simultaneously.All scans yield similar behaviour of the Ti and the Nb signals. This provides clear evidence, that within well annealed implanted waveguides the Ti4+ and the Nb5+ ions occupy equivalent lattice positions.

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