Papers by Jeffrey Driscoll
39th European Conference and Exhibition on Optical Communication (ECOC 2013), 2013
A silicon photonic waveguide system with mode-division and wavelength-division-multiplexing capab... more A silicon photonic waveguide system with mode-division and wavelength-division-multiplexing capabilities is demonstrated. Error-free (BER < 10 −12) data transmission of 2 modal channels and 3wavelengths operating with aggregate bandwidth of 60-Gb/s is realized. This work motivates future bandwidth scalability of silicon photonic interconnects.
Nanoengineering: Fabrication, Properties, Optics, and Devices X, 2013
We present a comprehensive study of generation and collision of optical similaritons in sub-micro... more We present a comprehensive study of generation and collision of optical similaritons in sub-micron silicon photonic wire waveguides. Our analysis of optical pulse dynamics in such wave guiding devices is based on a rigorous theoretical model that incorporates all of the relevant linear and nonlinear optical effects, including modal dispersion, free-carrier dispersion and absorption, self-phase modulation, two-photon absorption, frequency dispersion of the optical nonlinearity, and the free-carrier dynamics. In addition to the particular characteristics of the generation of optical similaritons in silicon photonic wires, we also investigate the dependence of the efficiency of this optical process on the physical parameters and temporal profile of the input pulse. The collision of optical similaritons that propagate both in the normal and anomalous dispersion regime is also analyzed. Guided by the target applications of our study, we considered two technologically relevant spectral regions, namely, telecom and mid-IR frequency domains.
Silicon Photonics and Photonic Integrated Circuits IV, 2014
We demonstrate enhanced conversion efficiency (CE) and parametric amplification of optical pulses... more We demonstrate enhanced conversion efficiency (CE) and parametric amplification of optical pulses via quasiphase-matched four-wave-mixing (FWM) in long-period Bragg waveguides made of silicon. Our study is based on a rigorous theoretical model that describes optical pulse dynamics in a periodically, adiabatically modulated silicon photonic waveguide and a comprehensive set of numerical simulations of pulse interaction in such gratings. More specifically, our theoretical model takes into account all of the relevant linear and nonlinear optical effects, including free-carriers generation, two-photon absorption, and self-phase modulation, as well as modal frequency dispersion up to the fourth-order. Due to its relevance to practical applications, a key issue investigated in our work is the dependence of the efficiency of the FWM process on the waveguide parameters and the operating wavelength. In particular, our analysis suggests that by varying the waveguide width by just a few tens of nanometers the wavelengths of the phase-matched waves can be shifted by hundreds of nanometers. Our numerical simulations show also that, in the anomalous group-velocity dispersion regime, a CE enhancement of more than 20 dB, as compared to the case of a waveguide with constant width, can be easily achieved.
Optics letters, 2014
We present a theoretical analysis supported by comprehensive numerical simulations of quasi-phase... more We present a theoretical analysis supported by comprehensive numerical simulations of quasi-phase-matched four-wave mixing (FWM) of ultrashort optical pulses that propagate in weakly width-modulated silicon photonic nanowire gratings. Our study reveals that, by properly designing the optical waveguide such that the interacting pulses copropagate with the same group velocity, a conversion efficiency enhancement of more than 15 dB, as compared to a uniform waveguide, can readily be achieved. We also analyze the dependence of the conversion efficiency and FWM gain on the pulse width, time delay, walk-off parameter, and grating modulation depth.
Conference on Lasers and Electro-Optics/International Quantum Electronics Conference, 2009
Silicon-on-insulator (SOI) has been used as a platform for nearinfrared photonic devices for more... more Silicon-on-insulator (SOI) has been used as a platform for nearinfrared photonic devices for more than twenty years. Longer wavelengths, however, may be problematic for SOI due to higher absorption loss in silicon dioxide. In this paper we report propagation loss measurements for the longest wavelength used so far on SOI platform. We show that propagation losses of 0.6-0.7 dB/cm can be achieved at a wavelength of 3.39 µm. We also report propagation loss measurements for silicon on porous silicon (SiPSi) waveguides at the same wavelength.
Optics Express, 2009
We report the demonstration of an all-optical, bias free and errorfree (bit-error-rate ~10 -12 ),... more We report the demonstration of an all-optical, bias free and errorfree (bit-error-rate ~10 -12 ), 10Gbit/s non-return-to-zero (NRZ) to return-tozero (RZ) data format conversion using a 7.5µm diameter III-V-on-silicon microdisk resonator. The device is completely processed in a 200mm CMOS pilot line. The data format conversion is based on the phenomenon of pulse carving of an NRZ optical data stream by an optical clock. The underlying physical effect for the pulse carving is the change in the refractive index caused by the generation of free-carriers in a pump -probe configuration. We believe it to be the first NRZ-to-RZ format convertor built on a hybrid III-V-on-silicon technology platform.
Optics Express, 2014
We present a comprehensive analysis of pulse compression in adiabatically tapered silicon photoni... more We present a comprehensive analysis of pulse compression in adiabatically tapered silicon photonic wire waveguides (Si-PhWWGs), both at telecom (λ ∼ 1.55 µm) and mid-IR (λ 2.1 µm) wavelengths. Our theoretical and computational study is based on a rigorous model that describes the coupled dynamics of the optical field and photogenerated free carriers, as well as the influence of the physical and geometrical parameters of the Si-PhWWGs on these dynamics. We consider both the soliton and non-soliton pulse propagation regimes, rendering the conclusions of this study relevant to a broad range of experimental settings and practical applications. In particular, we show that by engineering the linear and nonlinear optical properties of Si-PhWWGs through adiabatically varying their width, one can achieve more than 10× pulse compression in millimeter-long waveguides. The interdependence between the pulse characteristics and compression efficiency is also discussed.
IEEE Photonics Technology Letters, 2015
An on-chip error-free 40Gb/s-aggregated-data-rate link is achieved by transmitting a single wavel... more An on-chip error-free 40Gb/s-aggregated-data-rate link is achieved by transmitting a single wavelength of dual polarization-multiplexed (pol-mux) data at 10Gb/s through a two-mode mode-division-multiplexing (MDM) chip, with a power penalty of < 5 dB/channel. This is the first system-level experimental demonstration of combining pol-mux with MDM to enhance the performance of an on-chip Si photonics network, illustrating the potential for reduced total system electrical power budget by utilizing multiple data channels with a single laser.
Optics express, Jan 3, 2014
CMOS-compatible Si⁺-implanted Si-waveguide p-i-n photodetectors operating at room temperature and... more CMOS-compatible Si⁺-implanted Si-waveguide p-i-n photodetectors operating at room temperature and at mid-infrared wavelengths from 2.2 to 2.3 µm are demonstrated. Responsivities of 9.9 ± 2.0 mA/W are measured at a 5 V reverse bias with an estimated internal quantum efficiency of 2.7 - 4.5%. The dark current is found to vary from a few microamps down to less than a nanoamp after a post-implantation annealing of 350°C. The measured photocurrent dependence on input power shows a linear correspondence over more than three decades, and the frequency response of a 250 µm-length p-i-n device is measured to be ~1.7 GHz for a wavelength of λ = 2.2 µm, thus potentially opening up new communication bands for photonic integrated circuits.
Optics express, Jan 28, 2014
Mode-division-multiplexing (MDM) and wavelength-division-multiplexing (WDM) are employed simultan... more Mode-division-multiplexing (MDM) and wavelength-division-multiplexing (WDM) are employed simultaneously in a multimode silicon waveguide to realize on-chip MDM and MDM-WDM transmission. Asymmetric Y-junction MDM multiplexers and demultiplexers are utilized for low coherently suppressed demultiplexed crosstalk at the receiver. We demonstrate aggregate bandwidths of 20 Gb/s and 60 Gb/s for MDM and MDM-WDM on-chip links, respectively, with measured 10(-9) BER power penalties between 0.1 dB and 0.7 dB per channel.
Optics Letters, 2013
We study the generation of parabolic self-similar optical pulses in tapered Si photonic nanowires... more We study the generation of parabolic self-similar optical pulses in tapered Si photonic nanowires (Si-PhNWs) both at telecom (λ = 1.55 µm) and mid-IR (λ = 2.2 µm) wavelengths. Our computational study is based on a rigorous theoretical model, which fully describes the influence of linear and nonlinear optical effects on pulse propagation in Si-PhNWs with arbitrarily varying width. Numerical simulations demonstrate that, in the normal dispersion regime, optical pulses evolve naturally into parabolic pulses upon propagating in millimeter-long tapered Si-PhNWs, with the efficiency of this pulse reshaping process being strongly dependent on the spectral and pulse parameter regime in which the device operates, as well as the particular shape of the Si-PhNW.
Optics Letters, 2013
Directional mode coupling in an asymmetric holey fiber coupler is demonstrated both numerically a... more Directional mode coupling in an asymmetric holey fiber coupler is demonstrated both numerically and experimentally for the first time. The holey fiber mode couplers have interesting spectral characteristics and are also found to exhibit increased dimensional tolerances. Following a design based on numerical investigations, a dual-core polymer holey fiber coupler for LP 01 and LP 11 mode multiplexing was fabricated via a drilling and drawing technique. The measurements are compared with the simulation results.
Optics Express, 2012
We experimentally demonstrate quasi-phase-matched (QPM) four-wave-mixing (FWM) in silicon (Si) na... more We experimentally demonstrate quasi-phase-matched (QPM) four-wave-mixing (FWM) in silicon (Si) nanowire waveguides with sinusoidally modulated width. We perform discrete wavelength conversion over 250 nm, and observe 12 dB conversion efficiency (CE) enhancement for targeted wavelengths more than 100 nm away from the edge of the 3-dB conversion bandwidth. The QPM process in Si nanowires is rigorously modeled, with results explaining experimental observations. The model is further used to investigate the dependence of the CE on key device parameters, and to introduce devices that facilitate wavelength conversion between the C-band and mid-IR. Devices based on a superposition of sinusoidal gratings are investigated theoretically, and are shown to provide CE enhancement over the entire C-band. Width-modulation is further shown to be compatible with zero-dispersion-wavelength pumping for broadband wavelength conversion. The results indicate that QPM via widthmodulation is an effective technique for extending the spectral domain of efficient FWM in Si waveguides.
Optics Express, 2011
We describe a concept for second-order nonlinear optical processes in silicon photonics. A silico... more We describe a concept for second-order nonlinear optical processes in silicon photonics. A silicon-organic hybrid (SOH) double slot waveguide is dispersion-engineered for mode phase-matching (MPM). The proposed waveguide enables highly efficient nonlinear processes in the mid-IR range. With a cladding nonlinearity of χ (2) = 230 pm/V and 20 dBm pump power at a CW wavelength of 1550 nm, we predict a gain of 14.7 dB/cm for a 3100 nm signal. The suggested structure enables for the first time efficient second-order nonlinear optical mixing in silicon photonics with standard technology.
Optical Fiber Communication Conference Postdeadline Papers, 2018
We report the first demonstration of a silicon photonic microring modulator with modulation data ... more We report the first demonstration of a silicon photonic microring modulator with modulation data rate up to 128 Gb/s (64 Gbaud PAM4). The microring modulator exhibits an electro-optic phase efficiency of Vπ•L = 0.52 V•cm, an electro-optic bandwidth of 50 GHz, and a measured transmitter dispersion eye closure quaternary (TDECQ) of 3.0 dB at this data rate. In addition, the resonant wavelength of the microring modulator can be tuned across a full free spectral range (FSR) using an integrated heater with a thermo-optic phase efficiency of 19.5 mW/π-phase shift.
Journal of Lightwave Technology, 2019
We report the first demonstration of a silicon photonic microring modulator with modulation data ... more We report the first demonstration of a silicon photonic microring modulator with modulation data rate up to 128 Gb/s (64 Gbaud PAM4). The microring modulator exhibits an electrooptic phase efficiency of V π • L = 0.52 V•cm, an electro-optic bandwidth of 50 GHz, and a measured transmitter dispersion eye closure quaternary of 3.0 dB at this data rate. In addition, the resonant wavelength of the microring modulator can be tuned across a full free spectral range using an integrated heater with a thermo-optic phase efficiency of 19.5 mW/π-phase shift.
Journal of Lightwave Technology, 2015
Single-mode Si-wire waveguides, fabricated in the Si-on-insulator (SOI) platform, are the basis f... more Single-mode Si-wire waveguides, fabricated in the Si-on-insulator (SOI) platform, are the basis for a growing number of potential applications in linear and nonlinear integrated optical devices and systems. This paper reviews the fundamental optical physics and behavior of these waveguides and demonstrates how their reduced transverse dimensions and index contrast lead to a series of unique and distinct modal properties. These properties include readily tunable waveguide dispersion (including dispersion flattening), large longitudinal fields, a decrease in group velocity over those of the bulk materials, and anisotropic nonlinear optical properties. In turn, new devices and device structures are achievable as a result of these features and examples of new device structures are provided.
See Profile
All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Ultra-Compact Silicon Waveguide Photodetectors Utilizing Critically-Coupled Photonic Crystal Cavities at 1.55 µm
Advanced Photonics Congress, 2012
ABSTRACT We present a waveguide photodetector design for weak absorbers, such as ion-implanted si... more ABSTRACT We present a waveguide photodetector design for weak absorbers, such as ion-implanted silicon and polysilicon, utilizing a critically-coupled 1D photonic crystal cavity. Device lengths of &lt; 15 µm can be achieved if scattering loss is managed.
Quasi-Phase-Matched Four-Wave-Mixing Seeded by Modulation Instability in Slab-Modulated Silicon Nanowires
Frontiers in Optics 2012/Laser Science XXVIII, 2012
ABSTRACT We demonstrate how quasi-phase-matching via slab-modulation can be used in conjunction w... more ABSTRACT We demonstrate how quasi-phase-matching via slab-modulation can be used in conjunction with modulation-instability to both broaden the modulation-instability sideband and seed additional enhanced sidebands for efficient four-wave-mixing. Enhanced sidebands exceeding 30 dB are shown.
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Papers by Jeffrey Driscoll