A5039873101- Photonic and Optical Devices
- Optical Network Technologies
- Advanced Photonic Communication Systems
- Semiconductor Lasers and Optical Devices
- Photonic Crystals and Applications
- Climate Change and Health Impacts
- Advanced Fiber Laser Technologies
- Urban Heat Island Mitigation
- Building Energy and Comfort Optimization
- Advanced Fiber Optic Sensors
- Health and Well-being Studies
- Thermoregulation and physiological responses
- Sleep and Work-Related Fatigue
- Neural Networks and Reservoir Computing
- Occupational Health and Safety Research
- Noise Effects and Management
- Advanced Optical Network Technologies
- Optical Coatings and Gratings
- Hearing Loss and Rehabilitation
- Air Quality and Health Impacts
- Semiconductor Quantum Structures and Devices
- Silicon Nanostructures and Photoluminescence
- Occupational Health and Safety Management
- Hearing, Cochlea, Tinnitus, Genetics
- Sleep and related disorders
Arak University of Medical Sciences
2015-2024
Islamic Azad University Shabestar
2021
Tehran University of Medical Sciences
2013-2017
Mellanox Technologies (United States)
2014-2016
Islamic Azad University of Tabriz
2016
Jahrom University of Medical Sciences
2014
Monterey Institute for Technology and Education
2011
Oracle (United States)
2010-2011
University of Bristol
1996-2005
AM Technology (United Kingdom)
1998-2003
We present a high-speed silicon optical modulator with low V(pp) (peak-to-peak driving voltage) and ultralow energy consumption based on microring resonator, the refractive index modulation achieved by electric-field-induced carrier depletion in reverse-biased lateral pn diode embedded ring structure. With of 2 V, we demonstrate 3 dB bandwidth 11 GHz, depth 6.5 together an insertion loss dB, 50 fJ per bit, small device active area approximately 1000 microm(2).
We present thermally tunable silicon racetrack resonators with an ultralow tuning power of 2.4 mW per free spectral range. The use free-standing undercut structures significantly enhances the efficiency, one order magnitude improvement that for previously demonstrated thermo-optic devices without undercuts. 10%-90% switching time is to be ~170 µs. Such low-power micro-resonators are particularly useful as multiplexing and wavelength-tunable microcavity modulators.
We measure linear optical dispersion, nonlinear refraction and two-photon absorption in a silicon waveguide at 1.54 μm wavelength. The total dispersion the was found to be −9.1 fs/(nm cm). At wavelength, coefficient 0.45 cm/GW π phase shift from self-phase modulation observed pulses of 60 W peak-coupled power, generated an amplified gain-switched laser diode.
We present a wavelength-tunable, compact, high speed and low power silicon microring modulator. With ring radius of 5 microm, we demonstrate modulator with 12.5 Gbps driving voltage 3 V to achieve approximately 6 dB extinction ratio in measurement. More importantly, tunability the resonant wavelength is accomplished by means microheater on top ring, an efficiency 2.4 mW/nm (2.4 mW needed tune 1 nm). This device aims solve narrow bandwidth problem microcavity modulators increase data optical...
We present thermally reconfigurable multiplexing devices based on silicon microring resonators with low tuning power and thermal crosstalk. Micro-heaters top of the rings are employed to tune resonant wavelengths through thermo-optic effect silicon. achieve a 21 mW per free spectral range for single ring by exploiting isolation trenches close waveguides. Negligible crosstalk is demonstrated spaced 15 microm, enabling compact devices. The time constant be less than 10 micros.
We demonstrate a compact, high speed Ge photodetector efficiently butt-coupled with large cross-section silicon-on-insulate (SOI) waveguide in which the p-i-n junction is placed horizontal direction to enable very operation. The demonstrated has an active area of only 0.8×10 μm2, greater than 32 GHz optical bandwidth, and responsivity 1.1 A/W at wavelength 1550 nm. Very importantly device can readily be integrated performance wavelength-division-multiplexing filters based on SOI form...
Previously demonstrated high-order silicon ring filters typically have bandwidths larger than 100 GHz. Here we demonstrate 1-2 GHz-bandwidth with very high extinction ratios (~50 dB). The waveguides employed to construct these propagation losses of ~0.5 dB/cm. Each a filter is thermally controlled by metal heaters situated on the top ring. With power dissipation ~72 mW, resonance can be tuned one free spectral range, resulting in wavelength-tunable optical filters. Both second-order and...
We demonstrate low loss shallow-ridge silicon waveguides with an average propagation of 0.274 + or - 0.008 dB/cm in the C-band (1530 nm 1565 nm). These have a cross section 0.25 microm by 2 and are fabricated standard photolithography dry etching. also investigate compact double-level taper which adiabatically couples light from these to strip enabling tight bends.
We demonstrate a very efficient high speed silicon modulator with an ultralow pi-phase-shift voltage-length product V(pi)L = 1.4V-cm. The device is based on Mach-Zehnder interferometer (MZI) fabricated using 0.25microm thick silicon-on-insulator (SOI) waveguide offset lateral PN junctions. Optimal carrier-depletion induced index change has been achieved through the optimization of overlap region carriers and photons. 3dB bandwidth typical 1mm long was measured to be more than 12GHz. An...
Using low parasitic microsolder bumping, we hybrid integrated efficient photonic devices from different platforms with advanced 40 nm CMOS VLSI circuits to build ultra-low power silicon transmitters and receivers for potential applications in high performance inter/intra-chip interconnects. We used a depletion racetrack ring modulator improved electro-optic efficiency allow stepper optical photo lithography reduced fabrication complexity. Integrated cascode 2 V driver, the transmitter...
We demonstrate a compact waveguide-based high-speed Ge electro-absorption (EA) modulator integrated with single mode 3 µm silicon-on-isolator (SOI) waveguide. The EA is based on horizontally-oriented p-i-n structure butt-coupled deep-etched silicon waveguide, which transitions adiabatically to shallow-etched large core SOI demonstrated device has active region of 1.0 × 45 µm(2), total insertion loss 2.5-5 dB and an extinction ratio 4-7.5 over wavelength range 1610-1640 nm -4V(pp) bias....
We demonstrate a high speed GeSi electro-absorption (EA) modulator monolithically integrated on 3 µm silicon-on-insulator (SOI) waveguide. The demonstrated device has compact active region of 1.0 × 55 μm(2), an insertion loss 5 dB and extinction ratio 6 at wavelength 1550 nm. broad operating range 35 nm bandwidth 40.7 GHz 2.8 V reverse bias. This energy efficient is key building block for optical interconnection applications.
Heat stress as a physical harmful agent can increase the risk of health and safety problems in different workplaces such mining. Although there are indices to assess heat imposed on workers, choosing best index for specific workplace is so important. Since various criteria affect an applicability, extracting most effective ones determining their weights help prioritize existing select optimal index. In order achieve this aim, present study compared some using methods. The viewpoints...
This paper reports a detailed theoretical study of the dynamics wavelength conversion using cross-gain and cross-phase modulation in semiconductor optical amplifiers (SOA's) involving large signal, multisection rate equation model. Using this model, recently reported experimental results have been correctly predicted effects electrical pumping on speed, index, phase variation converted signal considered. The model predicts, agreement with data, that recovery rates as low 12 ps are possible...
We describe the use of a silicon waveguide for two-photon absorption measurements in an autocorrelator which achieved peak-power average-power sensitivity 1 (mW)2 at 1.56 μm wavelength and was used to measure optical pulses generated by mode-locked fiber ring laser. The experimental results agreed with theoretical model two-photon-induced photocurrent generation inside waveguide.
Optical links have successfully displaced electrical when their aggregated bandwidth-distance product exceeds ~100 Gb/s-m because link energy per bit unit distance is lower. will continue to be adopted at distances of 1 m and below if power falls pJ/bit/m. Providing optical directly a switching/routing chip can significantly improve the switched energy/bit. We present an early experimental CMOS-vertical-cavity surface-emitting laser (VCSEL) system operating Gigabit Ethernet line rates that...
We present two effective approaches to improve the responsivity of high speed waveguide-based Ge photodetectors integrated on a 0.25 μm silicon-on-insulator (SOI) platform. The main cause poor is identified as metal absorption from top contact Ge. By optimizing thickness and offsetting window, we have demonstrated that can be improved 0.6A/W 0.95 A/W at 1550 nm with 36 GHz 3 dB bandwidth. also demonstrate wider device double offset contacts achieve 1.05 20
Fast, compact, and power-efficient silicon microcavity electro-optic modulators are expected to be critical components for chip-level optical interconnects. It is highly desirable that these can driven by voltage swings of 1 V or less reduce power dissipation make them compatible with supply levels associated current future complementary metal-oxide-semiconductor technology nodes. Here, we present a racetrack resonator modulator achieves over 8 dB modulation depth at 12.5 Gbps swing. In...
We present a broadband 2x2 electro-optic silicon switch with an ultralow switching power and fast time based on Mach-Zehnder interferometer (MZI). Forward-biased p-i-n junctions are employed to tune the phase of waveguides in MZI, achieve π-phase 0.6 mW drive voltage 0.83 V MZI arm length 4 mm. The 10%-90% is demonstrated be 6 ns. Optical crosstalk levels lower than -17 dB obtained for optical bandwidth 60 nm. free carrier induced refractive index change extracted from experimental results...
We report the design and characterization of external-cavity DBR lasers built with a III-V-semiconductor reflective-SOA spot-size converter edge-coupled to SOI waveguides containing Bragg grating mirrors. The un-cooled have wall-plug-efficiencies up 9.5% at powers 6 mW. are suitable for making power efficient, hybrid WDM transmitters in CMOS-compatible optical platform.
We report a vertical p-i-n thin-film germanium photodetector integrated on 3microm thick large core silicon-on-insulator (SOI) waveguides. The device demonstrates very high external responsivity due to the low fiber coupling loss width and thickness are carefully designed achieve yet retain high-speed performance. Even with included, has demonstrated greater than 0.7A/W at 1550nm for TM polarization 0.5A/W TE polarization. A dark current of 0.2microA -0.5V bias is reported. 3dB bandwidths...
Following significant research and development work over the past few years, silicon photonics has become a promising candidate to provide low-power, low-cost, high-speed photonic links for telecommunication, data communication, interconnect applications. A optical modulator is one of critical components these links. In this paper, we report on our recent progress in GeSi electro-absorption (EA) based Franz-Keldysh effect (FKE) integrated 3-μm silicon-on-insulator (SOI) platform. We first...
The technologies associated with integration and packaging have a significant impact on the overall system. In this paper, we review silicon photonic “macrochip” system its that will allow dense wavelength-division multiplexed optical links to be intimately integrated co-manufactured switching electronics. For happen, anticipate number of advances.
The purpose of this article is to examine the applicability Universal Thermal Climate Index (UTCI) index as an innovative for evaluating occupational heat stress in outdoor environments. 175 workers 12 open-pit mines Tehran, Iran were selected research study. First, environmental variables such air temperature, wet-bulb globe relative humidity and flow rate measured; then UTCI, temperature (WBGT) (HSI) indices calculated. Simultaneously, physiological parameters including heart rate, oral...