Shai Gertler

• Yale University

Wideband optical isolators are critical for the robust operation of virtually all photonic systems. However, they have been challenging to realize in the integrated form due to the incompatibility of magnetic media with these circuit technologies. Here we present the first-ever demonstration of an integrated non-magnetic optical isolator with terah...

Photonic design is a process of mathematical optimization of a desired objective (beam formation, mode conversion, etc.) subject to the constraint of Maxwell’s equations. Finding the optimal design is challenging: Generically, these problems are highly nonconvex and finding global optima is NP hard. Here, we show that the associated optimization pr...

New strategies for converting signals between optical and microwave domains could play a pivotal role in advancing both classical and quantum technologies. Traditional approaches to optical-to-microwave transduction typically perturb or destroy the information encoded on intensity of the light field, eliminating the possibility for further processi...

Optical nonreciprocity plays a key role in almost every optical system, directing light flow and protecting optical components from backscattered light. Controllable forms of on-chip nonreciprocity are needed for the robust operation of increasingly sophisticated photonic integrated circuits (PICs) in the context of classical and quantum computatio...

New strategies to convert signals between optical and microwave domains could play a pivotal role in advancing both classical and quantum technologies. Through recent studies, electro-optomechanical systems have been used to implement microwave-to-optical conversion using resonant optical systems, resulting in transduction over limited optical band...

Physical design refers to mathematical optimization of a desired objective (e.g. strong light--matter interactions, or complete quantum state transfer) subject to the governing dynamical equations, such as Maxwell's or Schrodinger's differential equations. Computing an optimal design is challenging: generically, these problems are highly nonconvex...

We demonstrate wideband strong coupling between two photonic bands via electrically-driven acousto-optic scattering. Based on this system, we demonstrate a non-magnetic, low-loss ( < 1 dB) and broadband (59 GHz 10 dB isolation bandwidth) optical isolator.

We demonstrate electrically-interfaced intramodal Brillouin scattering in an AlN-on-SOI photonic device. Our device exhibits efficient phase modulation with V π · L = 0.13 V·cm and can perform bidirectional optical-to-microwave conversion.

Strong coupling enables a diverse set of applications that include optical memories, non-magnetic isolators, photonic state manipulation, and signal processing. To date, strong coupling in integrated platforms has been realized using narrow-linewidth high-Q optical resonators. In contrast, here we demonstrate wideband strong coupling between two ph...

Optomechanical systems show great potential as quantum transducers and information storage devices for use in future hybrid quantum networks. In this context, optomechanical strong coupling can enable efficient, high-bandwidth, and deterministic transfer of quantum states. While optomechanical strong coupling has been realized at optical frequencie...

The growing demand for bandwidth makes photonic systems a leading candidate for future telecommunication and radar technologies. Integrated photonic systems offer ultra-wideband performance within a small footprint, which can naturally interface with fiber-optic networks for signal transmission. However, it remains challenging to realize narrowband...

We demonstrate an efficient non-magnetic optical isolator based on electrically-driven inter-band acousto-optic scattering in an AlN-on-SOI photonic device. The isolator exhibits < 1 dB insertion loss and 10 dB of isolation over a 50 GHz bandwidth.

We report nonreciprocal wave propagation with ~ 10dB nonreciprocity over a 32 nm optical bandwidth based on inter-band acousto-optic scattering within a silicon photonic waveguide system.

The canonical beam splitter—a fundamental building block of quantum optical systems—is a reciprocal element. It operates on forward- and backward-propagating modes in the same way, regardless of direction. The concept of nonreciprocal quantum photonic operations, by contrast, could be used to transform quantum states in a momentum- and direction-se...

We present narrowband RF-photonic filters in an integrated silicon platform. Using Brillouin interactions, the filters yield narrowband (∼MHZ) filter bandwidths with high signal rejection, and demonstrate tunability over a wide (∼GHz) frequency range.

As self-sustained oscillators, lasers possess the unusual ability to spontaneously synchronize. These nonlinear dynamics are the basis for a simple yet powerful stabilization technique known as injection locking, in which a laser’s frequency and phase can be controlled by an injected signal. Because of its inherent simplicity and favorable noise ch...

The ever-increasing demand for high speed and large bandwidth has made photonic systems a leading candidate for the next generation of telecommunication and radar technologies. The photonic platform enables high performance while maintaining a small footprint and provides a natural interface with fiber optics for signal transmission. However, produ...

Characterizing ultrashort optical pulses has always been a critical but difficult task, which has a broad range of applications. We propose and demonstrate a self-referenced method of characterizing ultrafast pulses with a multimode fiber. The linear and nonlinear speckle patterns formed at the distal end of a multimode fiber are used to recover th...

Multimode fibers are explored widely for optical communication, spectroscopy, imaging, and sensing applications. Here we demonstrate a single-shot full-field temporal measurement technique based on a multimode fiber. The complex spatiotemporal speckle field is created by a reference pulse propagating through the fiber, and it interferes with a sign...

In most practical scenarios, optical susceptibilities can be treated as a local property of a medium. For example, in the context of nonlinear optics we can typically treat the Kerr and Raman response as local, such that optical fields at one location do not produce a nonlinear response at distinct locations in space. This is because the electronic...

The ever-increasing demand for high speed and large bandwidth has made photonic systems a leading candidate for the next generation of telecommunication and radar technologies. The photonic platform enables high performance while maintaining a small footprint and provides a natural interface with fiber optics for signal transmission. However, produ...

As self-sustained oscillators, lasers possess the unusual ability to spontaneously synchronize. These nonlinear dynamics are the basis for a simple yet powerful stabilization technique known as injection locking, in which a laser's frequency and phase can be controlled by an injected signal. Due to its inherent simplicity and favorable noise charac...

Microwave photonic systems are compelling for their ability to process signals at high frequencies and over extremely wide bandwidths as a basis for next generation communication and radar technologies. However, many applications also require narrow-band (∼ MHz) filtering operations that are challenging to implement using optical filtering techniqu...

Within a Brillouin-based bulk crystalline cavity optomechanical system, we demonstrate high quantum cooperativities as well as strong coupling between infrared light and high-frequency (12.7 GHz) bulk acoustic modes.

We demonstrate injection-locked operation of a silicon-based Brillouin laser for the first time. The unique spatio-temporal inter-modal Brillouin dynamics enable nonreciprocal control and low-phase-noise operation within a monolithically integrated system.

We demonstrate multi-pole RF-photonic filters in an integrated silicon platform. Using Brillouin interactions, the filters yield a narrow passband (~MHZ), high out-of-band rejection (70 dB), and can be tuned over a wide range (GHz).

Characterizing ultrashort optical pulses has always been a critical but difficult task, which has a broad range of applications. We propose and demonstrate a self-referenced method of characterizing ultrafast pulses with a multimode fiber. The linear and nonlinear speckle patterns formed at the distal end of a multimode fiber are used to recover th...

Microwave photonic systems are compelling for their ability to process signals at high frequencies and over extremely wide bandwidths as a basis for next generation communication and radar technologies. However, many applications also require narrow-band $(\sim\text{MHz})$ filtering operations that are challenging to implement using optical filteri...

We grow accustomed to the notion that optical susceptibilities can be treated as a local property of a medium. In the context of nonlinear optics, both Kerr and Raman processes are considered local, meaning that optical fields at one location do not produce a nonlinear response at distinct locations in space. This is because the electronic and phon...

The ability to amplify light within silicon waveguides is central to the development of high-performance silicon photonic device technologies. To this end, the large optical nonlinearities made possible through stimulated Brillouin scattering offer a promising avenue for power-efficient all-silicon amplifiers, with recent demonstrations producing s...

Multimode fibers are widely explored for optical communication, imaging and sensing applications. The interference of fiber guided modes generates a speckle pattern, which has been used for high-precision spectroscopy, temperature, and strain sensing. Here we demonstrate a single-shot full-field temporal measurement technique based on a multimode f...

The ability to amplify light within silicon waveguides is central to the development of high-performance silicon photonic device technologies. To this end, the large optical nonlinearities made possible through stimulated Brillouin scattering offer a promising avenue for power-efficient all-silicon amplifiers, with recent demonstrations producing s...

We use strong and tailorable stimulated Brillouin scattering in silicon waveguides to demonstrate wideband nonreciprocity (>100 GHz), silicon-based Brillouin laser oscillators, and laser-cooling of a continuum of phonon modes.

Here, we demonstrate record-high Brillouin amplification (> 20 dB) and lossless nonreciprocity (28 dB) in an all-silicon device using a resonantly enhanced stimulated inter-modal Brillouin process.

The interaction between light and motion has been harnessed in the field of optomechanics to perform precision measurements, create complex quantum states, and build new technologies. Bulk acoustic wave (BAW) resonators are mechanical systems that have shown great potential for mediating interactions between a variety of quantum systems such as opt...

Non-reciprocal light propagation is essential to control optical crosstalk and back-scatter in photonic systems. However, realizing high-fidelity non-reciprocity in low-loss integrated photonic circuits remains challenging. Here, we experimentally demonstrate a form of non-local acousto-optic light scattering to produce non-reciprocal single-sideba...

Achieving nonreciprocal light propagation in photonic circuits is essential to control signal crosstalk and optical back-scatter. However, realizing high-fidelity nonreciprocity in low-loss integrated photonic systems remains challenging. In this paper, we experimentally demonstrate a device concept based on nonlocal acousto-optic light scattering...

We report non-reciprocal optical modulation and mode conversion mediated by an optically-driven acoustic wave. Through this process, we experimentally demonstrate >20 dB of nonreciprocity over a >1 nm optical bandwidth in an integrated silicon waveguide.

Significance The WHO estimates that respiratory syncytial virus (RSV) vaccination will be available in the next 5–10 y. To evaluate the population effectiveness of an RSV vaccination program in the United States, we developed a transmission model that integrates data on daily infectious viral load and behavior changes while symptomatic. Our model s...

BACKGROUND:Poverty has been implicated as a challenge in the control of the current Ebola outbreak in West Africa. Although disparities between affected countries have been appreciated, disparities within West African countries have not been investigated as drivers of Ebola transmission. To quantify the role that poverty plays in the transmission o...

Heat maps depicting zone-level contact matrices for July, August, and September 2014. Montserrado County, Liberia is comprised of 22 zones. Case investigation data on the zones of residence for cases and their reported contacts were used to generate relative probabilities of contacts between and within zones. Increasingly less inter-zone contacts w...

Frequency distributions for time between symptom onset and hospitalization from case investigation data. For each individual reporting current or prior hospitalization, the number of days between his/her date of symptom onset and date of hospital admission was calculated. Data are provided per epidemic month in 2014. (DOCX)

Temporal trends in Ebola-related behaviors and case fatality, stratified by socioeconomic status (SES). Data are provided per epidemic month in 2014. (DOCX)

Case classification data. The dataset consists information about individuals reported as suspected, probable, or confirmed Ebola cases in Montserrado County between February 28, 2014 and December 1, 2014. (XLSX)

Frequency distributions for time between symptom onset and death from case investigation data. For each non-surviving case, the number of days between his/her date of symptom onset and date of death was calculated. Data are provided per epidemic month in 2014. (DOCX)

Contact tracing data. The dataset consists of information on 1,585 suspected, probable, or confirmed cases whose contacts were traced between July 7, 2014 and October 28, 2014. (XLSX)

Frequency distributions for the number of contacts per case from case investigation data. Data are provided per epidemic month in 2014. (DOCX)

Histogram of a truncated gamma distribution for the rate ratio, or expected change in transmission rate given a tenfold change in viral load. (DOCX)

Background: The Ebola outbreak that is sweeping across West Africa is the largest, most volatile, and deadliest Ebola epidemic ever recorded. Liberia is the most profoundly affected country, with more than 3500 infections and 2000 deaths recorded in the past 3 months. Objective: To evaluate the contribution of disease progression and case fatali...