Search results for "Optoelectronics"
showing 10 items of 2306 documents
Bringing Plasmonics Into CMOS Photonic Foundries: Aluminum Plasmonics on Si$_{3}$N$_{4}$ for Biosensing Applications
2019
We present a technology platform supported by a new process design kit (PDK) that integrates two types of aluminum plasmonic waveguides with Si $_{3}$ N $_{4}$ photonics towards CMOS-compatible plasmo-photonic integrated circuits for sensing applications. More specifically, we demonstrate the fabrication of aluminum slot waveguide via e-beam lithography (EBL) on top of the Si $_{3}$ N $_{4}$ waveguide and an optimized fabrication process of aluminum plasmonic stripe waveguides within a CMOS foundry using EBL. Experimental measurements revealed a propagation length of 6.2 μm for the plasmonic slot waveguide in water at 1550 nm, reporting the first ever experimental demonstration of a plasmon…
Multilevel pattern generation by GaN laser lithography: an application to beam shaper fabrication
2006
The new GaN lasers represent a unique combination of compactness, reliability, energy efficiency, and short wavelength. With respect to the previous state of the art in direct laser write lithography, based on gas lasers, this is resulting in a breakthrough, and is opening the way to real desktop micropatterning. The field of diffractive optics can immediately benefit by the availability of a new breed of pattern generators, based on such sources, mainly for fast turnaround device development. This paper presents the technical advantages involved in the use of 405 nm GaN lasers for one-step multilevel patterning. Beam modulation, exposure control and overall process strategy are discussed. …
An Example of Ti:LiNbO3 Device Fabrication: The Mach-Zehnder Electrooptical Modulator
1994
Integrated optics on LiNbO3 has already reached a stage of maturity. Several manufacturers are producing standard and custom devices on LiNbO3 such as high speed (up to 20 GHz) phase and intensity modulators, switching matrices, hybrid optical gyroscopes, etc.1. Two techniques are commonly used to fabricate these devices: titanium indiffusion for 1.3 and 1.5 μm wavelength operation and annealed proton exchange (APE) at 0.8 μm, due to its higher power handling capacity.
Nonstoichiometric silica mask to fabricate reverse proton-exchange waveguides in lithium niobate crystals
2004
Producing channel waveguides requires a photolithographic mask, but the standard technique of using thermally evaporated metal films for proton exchange has proved to be unsuitable for withstanding the rather aggressive process of reverse proton exchange. We report the fabrication of a nonstoichiometric silica mask by ion-plating plasma-assisted deposition. This mask is strong enough to resist both direct and reverse proton exchange and is also compatible with anisotropic dry etching for patterning the mask and with electric field poling. Our technique is a practical alternative to the use of SiO2 sputtered masks.
Microreflectivity studies of wavelength control in oxidised AlGaAs microcavities
2003
Wet oxidation of GaAs/AlGaAs structures is an important technique in the processing of advanced devices such as vertical cavity surface emitting lasers (VCSELs). In one VCSEL application, the low-index and electrically-insulating AlxOy layers have been used to obtain high-reflectivity and broad bandwidth distributed Bragg reflector mirrors (DBRs). A further recent development has shown that combined lateral–vertical oxidation of intracavity AlGaAs layers can be used to tune the resonant wavelength of a semiconductor microcavity. The slow oxidation rate limits the lateral scale of practical wet oxidation to mesas structures of 50–100 μm in width. Therefore post-processing assessment of spect…
In-line fiber-optic sensors based on the excitation of surface plasma modes in metal-coated tapered fibers
2001
Abstract Metal-coated tapered fibers are reported as refractive index sensors based on the resonant excitation of surface plasma modes supported by the metal coating. The devices are easy to fabricate and constitute an alternative to metal-coated side-polished fibers and to other sensors made up of bulk components. We report the fabrication and power transmission properties of quasi-circular devices and asymmetric devices. Both sets of devices can be operated as wavelength output sensors, as well as amplitude output sensors. The transmittance of quasi-circular devices is polarization independent and it changes more than 30 dB as a function of external refractive index.
An Electrical Tuner to Command Optical NanoAntennas
2010
Optical antennas are passive device where fabrication designs decide operating frequency, gain and emission diagram. By introducing an electrically controllable load medium for the antenna, these characteristics can be externally controlled.
Optical Amplification in Hollow-Core Negative-Curvature Fibers Doped with Perovskite CsPbBr3 Nanocrystals
2019
| openaire: EC/H2020/820423/EU//S2QUIP We report a hollow-core negative-curvature fiber (HC-NCF) optical signal amplifier fabricated by the filling of the air microchannels of the fiber with all-inorganic CsPbBr3 perovskite nanocrystals (PNCs). The optimum fabrication conditions were found to enhance the optical gain, up to +3 dB in the best device. Experimental results were approximately reproduced by a gain assisted mechanism based on the nonlinear optical properties of the PNCs, indicating that signal regeneration can be achieved under low pump powers, much below the threshold of stimulated emission. The results can pave the road of new functionalities of the HC-NCF with PNCs, such as op…
CMOS-compatible nanoscale gas-sensor based on field effect
2009
The integration of a solid state gas sensor of the metal oxide sensor type into CMOS technology still is a challenge because of the high temperatures during metal oxide annealing and sensor operation that do not comply with silicon device stability. In the presence of an external electric field sensor sensitivity can be controlled through a change of the Fermi energy level and consequently it is possible to reduce the operation temperature. Based in this effect, a novel field effect gas sensor was developed resembling a reversed insulated : gate field effect transistor (IGFET) with the thickness of gas sensing layer in the range of the Debye length (L D ). Under these conditions the control…
All-fibered high-quality 1.5–2 THz femtosecond pulse sources
2009
Generation of high-quality ultra-high repetition rate optical pulse trains around 1.55µm has become increasingly interesting for many scientific applications such as optical sampling, ultra-high capacity transmission systems, component testing or nonlinear phenomena studies. Unfortunately, the current bandwidth limitations of optoelectronic devices do not enable the direct generation of pulses with repetition rate higher than 80GHz and a temporal width below a few ps.