Polarization Characteristics of Compact SOI Rib Waveguide RaceTrack Resonators

Cataloged from PDF version of article.We report on the development of compact optical racetrack resonators on silicon-on-insulator (SOI) rib waveguides. We make use of large-cross-section waveguides instead of photonic wire waveguides. We fabricated resonators with bending radii down to 20 mu m and characterized for both transverse-electric and transverse-magnetic polarizations. Different polarization characteristics were analyzed and related to the modal shape of the SOI waveguide. These compact resonators show large free spectral ranges (3.0 nm), high finesse (19), and Q-factor (28 000) values

A Compact Silicon-on-insulator Polarization Splitter

Cataloged from PDF version of article.A compact directional coupler-based polarization splitter is designed and realized using silicon-on-insulator (SOI) waveguides. Even though silicon does not have any material birefringence, the high index contrast obtained in the SOI platform and reduced waveguide dimensions makes it possible to induce significant birefringence. Polarization splitting is achieved by making use of this geometry-induced birefringence. In this work, we demonstrate polarization splitting in devices as short as 120 gm. Even smaller devices can be made using submicron-thick Si waveguides

Low-Power Thermooptical Tuning of SOI Resonator Switch

Cataloged from PDF version of article.A wavelength selective optical switch is developed based on a high-Q racetrack resonator making use of the large thermooptic coefficient of silicon. The racetrack resonator was fabricated using a silicon-on-insulator (SOI) single-mode rib waveguide. The resonator shows a high Q factor of 38000 with spectral sidelobes of 11 dB down and can be thermooptically scanned over its full free-spectral range applying only 57 mW of electrical power. A low power of 17 mW is enough to tune the device from resonance to off-resonance state. The device functions as a wavelength selective optical switch with a 3-dB cutoff frequency of 210 kHz

Integrated asymmetric vertical coupler pressure sensors

Design and analysis of a novel pressure sensor based on a silicon-on-insulator asymmetric integrated vertical coupler is presented. The coupler is composed of a single mode low index waveguide and a thin silicon slab. Wavelength selective optical modulation of asymmetric vertical coupler is examined in detail. Its potential for sensing applications is highlighted as an integrated optical pressure sensor which can be realized by standard silicon micro-fabrication. Sensitivity of transmission of such couplers on refractive index change of silicon slab ensures that they are good candidates for applications requiring high sensitivities

Integrated micro ring resonator displacement sensor for scanning probe microscopies

We describe a novel displacement sensor for scanning probe microscopies using an integrated optical micro ring resonator. This device operates by means of monitoring the changes in the transmission spectrum of a high finesse micro ring resonator. Finite element method simulations were carried out to obtain the optimum sensor design and finite difference time domain simulation was used to obtain the transfer characteristics of micro ring resonators. Operation principles and sensitivity calculations are discussed in detail. To achieve high sensitivity, we have studied different types of ring resonator. The highest sensitivity is obtained in a race-track resonator. This new design should provide sensitivities as high as ∼10 -4 Å -1

Pressure sensing using micromachined asymmetric integrated vertical coupler

Analysis of a novel pressure sensor based on a SOI asymmetric vertical coupler is presented. The integrated optical component is a coupler composed of a single mode low index waveguide and a thin silicon slab

Novel integrated optical displacement sensor for scanning force microscopies

A novel displacement sensor for scanning force microscoples using an integrated optical micro-ring resonator is described. Device operates by monitoring the changes in transmission spectrum of micro-ring resonator. This design provides sensitivities about ∼10-4 Å-1

Cornea engineering on polyester carriers

In this study, biodegradable polyester based carriers were designed for tissue engineering of the epithelial and the stromal layers of the cornea, and the final construct was tested in vitro. In the construction of the epithelial layer, micropatterned films were prepared from blends of biodegradable and biocompatible polyesters of natural (PHBV) and synthetic (P(L/DL)LA) origin, and these films were seeded with D407 (retinal pigment epithelial) cells. To improve cell adhesion and growth, the films were coated with fibronectin. To serve as the stromal layer of the cornea, highly porous foams of P(L/DL)LA-PHBV blends were seeded with 3T3 fibroblasts. Cell numbers on the polyester carriers were significantly higher than those on the tissue culture polystyrene control. The cells and the carriers were characterized scanning electron micrographs showed that the foam was highly porous and the pores were interconnected. 3T3 Fibroblasts were distributed quite homogeneously at the seeding site, but probably because of the high thickness of the carrier (∼6 mm); they could not sufficiently populate the core (central parts of the foam) during the test duration. The D407 cells formed multilayers on the micropatterned polyester film. Immunohistochemical studies showed that the cells retained their phenotype during culturing; D407 cells formed tight junctions characteristic of epithelial cells, and 3T3 cells deposited collagen type I into the foams. On the basis of these results, we concluded that the micropatterned films and the foams made of P(L/DL)LA-PHBV blends have a serious potential as tissue engineering carriers for the reconstruction of the epithelial and stromal layers of the cornea. © 2006 Wiley Periodicals, Inc

Integrated photonic quantum gates for polarization qubits

Integrated photonic circuits have a strong potential to perform quantum information processing. Indeed, the ability to manipulate quantum states of light by integrated devices may open new perspectives both for fundamental tests of quantum mechanics and for novel technological applications. However, the technology for handling polarization encoded qubits, the most commonly adopted approach, is still missing in quantum optical circuits. Here we demonstrate the first integrated photonic Controlled-NOT (CNOT) gate for polarization encoded qubits. This result has been enabled by the integration, based on femtosecond laser waveguide writing, of partially polarizing beam splitters on a glass chip. We characterize the logical truth table of the quantum gate demonstrating its high fidelity to the expected one. In addition, we show the ability of this gate to transform separable states into entangled ones and vice versa. Finally, the full accessibility of our device is exploited to carry out a complete characterization of the CNOT gate through a quantum process tomography.Comment: 6 pages, 4 figure

A compact silicon-on-insulator polarization splitter

A compact directional coupler-based polarization splitter is designed and realized using silicon-on-insulator (SOI) waveguides. Even though silicon does not have any material birefringence, the high index contrast obtained in the SOI platform and reduced waveguide dimensions makes it possible to induce significant birefringence. Polarization splitting is achieved by making use of this geometry-induced birefringence. In this work, we demonstrate polarization splitting in devices as short as 120 μm. Even smaller devices can be made using submicron-thick Si waveguides. © 2005 IEEE