Waveguide based compact silicon Schottky photodetector with enhanced responsivity in the telecom spectral band.

We experimentally demonstrate an on-chip compact and simple to fabricate silicon Schottky photodetector for telecom wavelengths operating on the basis of internal photoemission process. The device is realized using CMOS compatible approach of local-oxidation of silicon, which enables the realization of the photodetector and low-loss bus photonic waveguide at the same fabrication step. The photodetector demonstrates enhanced internal responsivity of 12.5mA/W for operation wavelength of 1.55µm corresponding to an internal quantum efficiency of 1%, about two orders of magnitude higher than our previously demonstrated results [22]. We attribute this improved detection efficiency to the presence of surface roughness at the boundary between the materials forming the Schottky contact. The combination of enhanced quantum efficiency together with a simple fabrication process provides a promising platform for the realization of all silicon photodetectors and their integration with other nanophotonic and nanoplasmonic structures towards the construction of monolithic silicon opto-electronic circuitry on-chip.

Plasmonic nanofocusing of light in an integrated silicon photonics platform.

The capability to focus electromagnetic energy at the nanoscale plays an important role in nanoscinece and nanotechnology. It allows enhancing light matter interactions at the nanoscale with applications related to nonlinear optics, light emission and light detection. It may also be used for enhancing resolution in microscopy, lithography and optical storage systems. Hereby we propose and experimentally demonstrate the nanoscale focusing of surface plasmons by constructing an integrated plasmonic/photonic on chip nanofocusing device in silicon platform. The device was tested directly by measuring the optical intensity along it using a near-field microscope. We found an order of magnitude enhancement of the intensity at the tip's apex. The spot size is estimated to be 50 nm. The demonstrated device may be used as a building block for "lab on a chip" systems and for enhancing light matter interactions at the apex of the tip.

Locally oxidized silicon surface-plasmon Schottky detector for telecom regime.

We experimentally demonstrate an on-chip nanoscale silicon surface-plasmon Schottky photodetector based on internal photoemission process and operating at telecom wavelengths. The device is fabricated using a self-aligned approach of local-oxidation of silicon (LOCOS) on silicon on insulator substrate, which provides compatibility with standard complementary metal-oxide semiconductor technology and enables the realization of the photodetector and low-loss bus photonic waveguide at the same fabrication step. Additionally, LOCOS technique allows avoiding lateral misalignment between the silicon surface and the metal layer to form a nanoscale Schottky contact. The fabricated devices showed enhanced detection capability for shorter wavelengths that is attributed to increased probability of the internal photoemission process. We found the responsivity of the nanodetector to be 0.25 and 13.3 mA/W for incident optical wavelengths of 1.55 and 1.31 μm, respectively. The presented device can be integrated with other nanophotonic and nanoplasmonic structures for the realization of monolithic opto-electronic circuitry on-chip.

Two-photon absorption in an atomic cladding wave guide

We experimentally demonstrate two-photon Doppler free interactions on a chip-scale platform consisting of a silicon nitride waveguide integrated with rubidium vapor cladding. We obtain absorption lines having widths of 300 MHz, using low power levels. © OSA 2013.

Two-photon absorption in an atomic cladding wave guide

We experimentally demonstrate two-photon Doppler free interactions on a chip-scale platform consisting of a silicon nitride waveguide integrated with rubidium vapor cladding. We obtain absorption lines having widths of 300 MHz, using low power levels. © OSA 2013.

Light-matter interactions in atomic cladding wave guides

We experimentally demonstrate light-matter interactions on a chip, consisting of a silicon nitride wave-guide integrated with rubidium vapor cladding. The measured absorption spectra provide indications for low light nonlinear interactions. © 2012 OSA.

Silicon-metal waveguide as a high efficiency Schottky detector for telecom wavelengths

We demonstrate an integrated on-chip compact and high efficiency Schottky detector for telecom wavelengths based on silicon metal waveguide. Detection is based on the internal photoemission process. Theory and experimental results are discussed. © 2012 OSA.

Light-matter interactions in atomic cladding wave guides

We experimentally demonstrate light-matter interactions on a chip, consisting of a silicon nitride wave-guide integrated with rubidium vapor cladding. The measured absorption spectra provide indications for low light nonlinear interactions. © OSA 2012.

Parabolic tapered photonic crystal cavity in silicon

We demonstrate the design, fabrication, transmission spectrum measurement, and near-field characterization of a parabolic tapered one-dimensional photonic crystal cavity in silicon. The results shows a relatively high quality factor (∼43 000), together with a small modal volume of ∼ 1. 1 (λ/n) 3. Moreover, the design allows repeatable device fabrication, as evident by the similar characteristics obtained for several tens of devices that were fabricated and tested. These demonstrated 1D PhC cavities may be used as a building block in integrated photonic circuits for optical on-chip interconnects and sensing applications. © 2012 American Institute of Physics.

Locally-oxidized silicon surface-plasmon Schottky detector for telecom wavelengths

We demonstrate an integrated on-chip locally-oxidized silicon surface-plasmon Schottky detector for telecom wavelengths based on the internal photoemission process. Theoretical model and experimental results will be presented and discussed. © 2011 IEEE.

Locally oxidized silicon surface-plasmon Schottky detector for telecom regime

We experimentally demonstrate an on-chip nanoscale silicon surface-plasmon Schottky photodetector based on internal photoemission process and operating at telecom wavelengths. The device is fabricated using a self-aligned approach of local-oxidation of silicon (LOCOS) on silicon on insulator substrate, which provides compatibility with standard complementary metal-oxide semiconductor technology and enables the realization of the photodetector and low-loss bus photonic waveguide at the same fabrication step. Additionally, LOCOS technique allows avoiding lateral misalignment between the silicon surface and the metal layer to form a nanoscale Schottky contact. The fabricated devices showed enhanced detection capability for shorter wavelengths that is attributed to increased probability of the internal photoemission process. We found the responsivity of the nanodetector to be 0.25 and 13.3 mA/W for incident optical wavelengths of 1.55 and 1.31 μm, respectively. The presented device can be integrated with other nanophotonic and nanoplasmonic structures for the realization of monolithic opto-electronic circuitry on-chip. © 2011 American Chemical Society.

Experimental demonstration of locally oxidized hybrid silicon-plasmonic waveguide

We experimentally demonstrate a self-aligned approach for the fabrication of nanoscale hybrid silicon-plasmonic waveguide fabricated by local oxidation of silicon (LOCOS). Implementation of the LOCOS technique provides compatibility with standard complementary metal-oxide-semiconductor technology and allows avoiding lateral misalignment between the silicon waveguide and the upper metallic layer. We directly measured the propagation and the coupling loss of the fabricated hybrid waveguide using a near-field scanning optical microscope. The demonstrated structure provides nanoscale confinement of light together with a reasonable propagation length of ∼100 μm. As such, it is expected to become an important building block in future on-chip optoelectronic circuitry. © 2010 American Institute of Physics.

Polarization switching induced decrease of bulk resistivity in ferroelectric Pb(Zr0.45Ti0.55)O3 thin films and a method to improve their fatigue endurance

Significant reduction of the bulk resistivity in a ferroelectric Pb(Zr 0.45Ti0.55)O3 thin film is observed before the remnant polarization started to decrease noticeably at the onset of its fatigue switching process. It is associated with the increase of charge carriers within the central bulk region of the film. The decrease of bulk resistivity would result in the increase of Joule heating effect, improving the temperature of the thin film, which is evaluated by the heat conduction analysis. The Joule heating effect in turn accelerates the polarization reduction, i.e. fatigue. Enhancing the heat dissipation of a ferroelectric capacitor is shown to be able to improve the device's fatigue endurance effectively. © 2013 Chinese Physical Society and IOP Publishing Ltd.

800V lateral IGBT in bulk Si for low power compact SMPS applications

An 800V rated lateral IGBT for high frequency, low-cost off-line applications has been developed. The LIGBT features a new method of adjusting the bipolar gain, based on a floating N+ stripe in front of the P+ anode/drain region. The floating N+ layer enhances the carrier recombination at the anode/drain side of the drift region resulting in a very significant decrease in the turn-off speed and substantially lower overall losses. Switching speeds as low as 140ns at 25oC and 300ns at 125oC have been achieved with corresponding equivalent Rdson at 125oC below 90mω.cm2. A fully operational AC-DC converter using a controller with an integrated LIGBT+depletion mode MOSFET chip has been designed and qualified in plastic SOP8 packages and used in 5W, 65kHz SMPS applications. The device is fabricated in 0.6μm bulk silicon CMOS technology without any additional masking steps. © 2013 IEEE.

Demonstration of a self aligned hybrid silicon-plasmonic waveguide with low loss and nanoscale confinement

We demonstrate self-aligned approach for fabricating hybrid silicon plasmonic waveguide. The demonstrated structure provides nanoscale confinement together with propagation length of 100 microns on chip. Near-field measurements of propagation and coupling loss are presented. © 2011 Optical Society of America.