### Biography

Welcome to my group's webpage. My name is Ksenia Dolgaleva; I am an Assistant Professor at the University of Ottawa and a Tier 2 Canada Research Chair in Integrated Photonics. My primary affiliation is with the School of Electrical Engineering and Computer Science, Faculty of Engineering. Because I studied to become a physicist, I am also cross-appointed with the Department of Physics, Faculty of Science. I have always been intrigued by fundamental physics, and at the same time, I enjoy the excitement of engineering research. During my undergraduate, Ph.D., and postdoctoral studies, I was lucky to gain experience in both, and I presently carry on both fundamental and applied research. The following two links will give you an idea about my primary research directions in both physics and engineering physics.

### And here is what brought me to where I am now...

I was born in Astrakhan, Russia (at that time Soviet Union). It is an old city situated at the southwest of Russia, just north of Caspian Sea, where the River Volga enters the sea. Part of my family still lives there, and I visit them from time to time. My parents travelled all over the country since I was born, and I never spent more than 3—4 years in the same city. When I was 3—4 years old, I lived in Siberia in Zlatoust, then in Tomsk. I started elementary school in Mukachevo, Ukraine when I was 6 years old. At the age of 10, I went back to live in Astrakhan with my grandparents for a couple of years, and then followed my parents to Murmansk, the northwest of Russia, close to Scandinavia. There I finished my middle and high school with honours and a Silver Medal. At that time, I established my interest to become a physicist.

With this thought in mind, I went to Moscow at the age of 16 to take entrance examinations for the Faculty of Physics at Lomonosov Moscow State University, and got admitted to the program. I made a personal commitment to achieve more than just completing a degree in Physics. I wanted to work my way up to become a Professor of Physics to teach fundamental subjects and to do research in Physics.

During the first two years at physics program in Moscow State University, we studied quite profoundly four sub-areas of Physics: Mechanics, Molecular Physics, Electricity and Magnetism, and Optics. The latter caught my attention and became the subject of passion that I carry throughout my entire career. While studying Quantum Mechanics and Atomic Physics during the third and fourth years at the university, I realized that Optics includes these two exciting disciplines as well, and there was no doubt that I should choose Optics as the field of my specialization. So I did, selecting the Department of Optics and Spectroscopy to complete my undergraduate research and Diploma in Physics (an equivalent of the North-American Master degree).

Preoccupied with the thought of becoming a Professor in Physics who specializes in Optics, I finished my undergraduate program in Moscow and moved to Rochester, NY (USA) in 2001 to perform my doctoral studies at the Institute of Optics, the University of Rochester. Moscow State University gave me a solid fundamental background in Physics and Mathematics. It was time to give this knowledge some practical twist, while expanding it further. The Institute of Optics was a perfect place to start gaining this different practical perspective while enhancing and deepening the fundamental background.

I was accepted to the research group of Prof. Robert Boyd where I've been working on my Ph.D. thesis for a few years. Needless to say, it was an amazing experience: I could not believe how lucky I was to have gotten this opportunity to learn Nonlinear Optics from the world-famous expert in the field. Since then, it became my primary subject of interest: all my research is centred around Nonlinear Optics. Among the projects that I've been working on as a part of my Ph.D. were nanocomposite optical materials, local-field effects, chiral metasurfaces, cholesteric liquid crystal lasers, 1D photonic crystal structures for enhanced nonlinear optical interactions, and many others. Once I have completed my Ph.D. in Optics at the University of Rochester, I moved to Toronto, Canada to work with Prof. Stewart Aitchison on integrated optical devices based on AlGaAs at the Department of Electrical and Computer Engineering, the University of Toronto. It was a very valuable (and a very different) experience. The devices I worked on had a direct practical implication. A completely new field opened up to me: integrated photonics for optical communications. I realized how powerful an impact of integrated photonics could be and decided to work on developing all-optical signal processing functions on a chip.

I have joined the School of Electrical Engineering and Computer Science in July 2013 as an Assistant Professor and as a member of the Quantum Photonics team lead by Prof. Robert Boyd at the University of Ottawa. I am currently in the process of starting my research group, and I am looking to hire promising undergraduate and graduate students interested at performing research in Optics and Photonics.

### Education

Post-doctoral researcher January 2014 - November 2014 (Aalto University School of Science, Finland)
Post-doctoral researcher September 2013 - December 2013 (Tampere University of Technology, Finland)
D.Sc. (with distinction) February 2009 - June 2013 (Tampere University of Technology, Finland)
M.Sc. (with distinction) September 2004 - January 2009 (Tampere University of Technology, Finland)

### Biography

Dr. Mikko Huttunen received his degree of D.Sc. (Technology) from the Tampere University of Technology in 2013. The title of his Thesis was Second-harmonic Generation with Focused Vector Beams including both experimental and computational work to better understand the nonlinear light-matter interactions occurring at the focal volume of tightly focused vector beams. This understanding was then utilized for developing novel material characterization techniques. Prior to joining the Quantum Photonics group in 2015, Dr. Huttunen was a post-doctoral fellow in Quantum Dynamics group in Aalto University School of Science, studying surface lattice resonances of nanoparticle arrays. His current research interests include development of novel nonlinear microscopy techniques, understanding chiral light-matter interactions and studying nonlinear plasmonic systems. One longer term goal is to develop better ways to enhance and control nonlinear light-matter interactions at the nanoscale for realizing novel chip-scale photonics devices.

### Contact

Mikko J. Huttunen
Room ARC 454
Office: +1 (613) 562-5800 Ext. 7138
E-mail: mhuttune(at)uottawa(dot)ca

### Publications

1. Surface lattice resonances and magneto-optical response in magnetic nanoparticle arrays, Nature Communications 6, 7072 (2015).
2. Second-harmonic generation imaging of semiconductor nanowires with focused vector beams, Nano Letters 15, 1564—1569 (2015).
3. Nonlinear optical activity effects in complex anisotropic three-dimensional media, Optical Materials Express 5, 11—21 (2015).
4. Microscopic determination of second-order nonlinear optical susceptibility tensors, The Journal of Physical Chemistry C 118, 26409—26414 (2014).
5. Polarized third-harmonic generation imaging identifies compositionally different lipid droplets, Biophysical Journal 107, 2230—2236 (2014).
6. Three-dimensional winged nanocone optical antennas, Optics Letters 39, 3686—3689 (2014).
7. Three-dimensional structural imaging of starch granules by second-harmonic generation circular dichroism, Journal of Microscopy 253, 183—190 (2014).
8. Third-harmonic generation microscopy of individual metal nano-objects using cylindrical vector beams, Optics Express 21, 21918—21923 (2013).
9. Measurement of optical second-harmonic generation from an individual single-walled carbon nanotube, New Journal of Physics 15, 083043 (2013).
10. Chiral imaging of collagen by second-harmonic generation circular dichroism, Biomedical Optics Express 4, 909—916 (2013).
11. Multipolar second-harmonic emission with focused Gaussian beams, New Journal of Physics 14, 113005 (2012).
12. Second-harmonic generation imaging of metal nano-objects with cylindrical vector beams, Nano Letters 12, 3207—3212 (2012).
13. Polarization-controllable winged nanocone tip antenna, Journal of Nonlinear Optical Physics and Materials 4, 415 (2011).
14. Nonlinear chiral imaging of subwavelength-sized twisted-cross gold nanodimers [Invited], Optical Materials Express 1, 46—56 (2011).
15. Tip-enhanced Raman scattering from bridged nanocones, Optics Express 18, 23790—23795 (2010).
16. Absolute probe of surface chirality based on focused circularly polarized light, The Journal of Physical Chemistry Letters 1, 1826—1829 (2010).
17. Absolute nonlinear optical probes of surface chirality, Journal of Optics A: Pure and Applied Optics 11, 034006 (2009).
18. Nanoimprint fabrication of gold nanocones with ~10 nm tip for enhanced optical interactions, Optics Letters 34, 1979—1981 (2009).

### Biography

Kashif Masud Awan joined the group in May 2013 as a PhD student. Previously he completed his Masters degree under an Erasmus Mundus Master of Photonics program that involved study in three univerities: St Andrews (UK), Heriot Watt (UK) and KTH (Sweden). His Master thesis was based on a study of GaAs nanowires design and fabrication for photovoltaic applications. He completed his bachelors in Electronics Engineering from National University of Sciences and Technology, Pakistan. He is currently involved in fabrication of integrated photonic devices and is interested in the study of nonlinear effects in integrated devices, specifically AlGaAs waveguides.

### Current projects

1. Design, fabrication and characterization of AlGaAs waveguides for optimized four-wave mixing. Intended application is all-optical wavelength conversion. Furthermore waveguides are the basic unit for integrated photonic devices and an optimized design for different applications is imperative for pursuing more complex devices.
2. Extending study of nonlinear characteristics of III-V semiconductors to other ternary and quaternary semiconductors that haven't been thoroughly studied before.
3. Fabrication of AlGaAs microring resonators for four-wave mixing applications. Microring resonators enhance the light matter interaction by having multiple passes of light through same region, hence increased Q-factor. Enhanced interaction leads to enhancement in nonlinear effects and this can increase efficiency of four-wave mixing conversion, making them attractive option for all-optical wavelength conversion.

### Biography

Payman joined Quantum Photonics group in Sep 2015 as a PhD student. He previously got his Bachelors degree from Shiraz University and Masters degree from Isfahan University of Technology (IUT) in Iran. During his Masters program, he studied Microwave Imaging, Passive Microwave Engineering and Electromagnetic Band Gap structures. He finally changed the topic and focused on Plasmonic structures. His Masters thesis under the supervision of Prof. Reza Safian was about designing an In-Line Fiber Plasmonic Polarizer. Currently, he is involved in fabrication of integrated photonic devices and is interested in the study of non-linear effects in integrated III-V semiconductor devices.

### Biography

Prova Christina Gomes has joined the group in 2014. She has received her B.Sc. in Electrical and Electronics Engineering from American International University-Bangladesh (AIUB). Her undergraduate thesis is based on multiple quantum well VCSEL using III-V Semiconductor materials. Now, she is doing her MASc in Electrical and Computer Engineering in the University of Ottawa. She is interested in Integrated Optics in III-V Semiconductors, especially waveguides and slow light photonic crystals.

### Biography

Shayan Saeidi passed his B.Sc. studies in electrical engineering at Amirkabir University of Technology (AUT), Iran. He joined Photonics Research Laboratory of AUT in early 2014 and received his B.Sc. in April 2015. The topic of his B.Sc. research was related to the optimization of the characteristics of germanium laser. He is currently pursuing his M.Sc studies in Quantum Photonics group at University of Ottawa. He is now interested in simulation and fabrication of III-V semiconductor compound lasers and passive components.

### Biography

Md Saad-Bin-Alam has joined the Nonlinear Photonics Group in 2016 as a MASc student of Electrical and Computer Engineering in University of Ottawa (uOttawa). He received his BSc in Electrical and Electronic Engineering from North South University (NSU), Bangladesh. Prior to joining this group, Saad worked as a research assistant in NSU under the supervision of Prof. Atiqur Rahman, where he did research on sub-wavelength optical Imaging and hybrid plasmonic nano-antenna. Besides, in his undergraduate thesis he also worked on RF energy harvesting circuit, narrow and ultra-wideband microwave antenna for different applications with Ms. Sanjida Moury. Saad is presently performing research in the field of plasmonics, metamaterials, nonlinear optics.

### Contact

Cell phone: +1 (613) 793 2205

### Publications

#### Journal Articles

1. M. Saad-Bin-Alam, M. I. Khalil, A. Rahman and Arshad M. Chowdhury, Hybrid plasmonic waveguide fed broadband nano-antenna for nanophotonic applications, IEEE Photonics Technology Letters, Vol. 27, Issue 10, pp. 1092-1095 (2015).
2. M. I. Khalil, M. Saad-Bin-Alam, A. Rahman, and Pavel A. Belov, Impact of filling ratio on subwavelength optical imaging using metallic nanolens of different geometries, Applied Optics, Vol. 53, Issue 26, pp. 6096-6102 (2014).

#### Conference Proceedings

1. M. Saad-Bin-Alam and S. Moury, Multiple-band antenna coupled rectifier circuit for ambient RF energy harvesting for WSN, IEEE proceedings in International Conference on Informatics, Electronics and Vision (ICIEV 2014), pp. 1-4, May 2014.
2. M. Saad-Bin-Alam and S. Moury, Conversion of an UWB antenna to dual band antenna for WBAN applications, IEEE proceedings in International Conference on Informatics, Electronics and Vision (ICIEV 2014), pp. 1-4, May 2014.
3. M. I. Khalil, M. Saad-Bin-Alam, and A. Rahman, Resolution limit of subwavelength optical imaging through Au-SiO2-Au nanorod arrays, IEEE proceedings in International Conference on Advances in Electrical Engineering (ICAEE 2013), pp. 129-131, December 2013.
4. M. Saad-Bin-Alam and S. Moury, Design of a narrowband 2.45 GHz unidirectional microstrip antenna with a reversed ‘Arrow’ shaped slot for fixed RFID tag and reader, IEEE proceedings in International Conference on Advances in Electrical Engineering (ICAEE 2013), pp. 301-304, December 2013.
5. M. Saad-Bin-Alam, M. S. Ullah, and S. Moury, Design of a low power 2.45 GHz RF energy harvesting circuit for rectenna, International Conference on Informatics, Electronics and Vision (ICIEV 2013), pp. 1-4, May 2013.

#### Dr. Lilian Sirbu

Dr. Lilian Sirbu earned both his Diploma in Microelectronics and Medical Equipment in (2002), and his Ph.D. in Physics and Mathematics from the Technical University of Moldova in 2011. He earned the "Doctoral thesis of excellence of 2011 year" at a national contest in the field of Exact and Technical sciences for his work on "Luminescence and THz wave emission from nanostructured materials based on III-V semiconductor compounds". During his Ph.D, he visited Prof. Robert W. Boyd at the Institute of Optics in Rochester NY, where he designed the necessary setups for studying PL and to assimilate other optical equipment for studying the SPR effects in III-V (A3B5) semiconductors doped with RE elements, and with Au, Ag nanodots epilayer deposited. This visit was supported by the Moldovan Travel Fellowship Program for Young Investigators.

Within the bilateral Moldovan-Romanian project (2010-2012) and the Young Scientist Program, he lead multiple teams from different institutions in the design of several "Lab on a Chip" devices (microfluidic chip) based on Electrowetting on Dielectric (EWOD) technic and THz emitter based on porous membrane. During this period he visited on several occasions the National Institute for Research and Development in Microtechnologies, and IMT Bucharest and National Institute for Laser, Plasma and Radiation Physics in Magurele, both in Romania. There he acquired knowledge for simulation and mask design software, such as CleWin, Ansys, OptiFDTD, and Coventor.

Throughout his career, Dr. Sirbu disseminated his findings in national and international conferences such as EMRS, TERAMIR, etc. in more than 50 presentations. From March to April 2013 he visited the Hannover Medical School, Department of Cardiothoracic, Transplantation and Vascular Surgery, were he worked side by side with doctors and biologists and in testing the biocompatibility (toxicity) of the EWOD microchip using the recellularisation technique, and experimenting with rat heart cells over structures like nanopillar shape ZnO, ITO, InP and PTFE. This involved designing the electrical circuits to achieve specific results using CAD softwares. Dr. Sirbu has published and co-authored around 28 articles in refereed journals.

Dr. Sirbu is currently a visiting researcher within the Canada Excellence Research Chair (CERC) Quantum Photonics group at the University of Ottawa. The goal of his visit is the collaboration with Drs. Ksenia Dolgaleva and Robert Boyd in the fields of THz sources and nonlinear materials, as well as III-V semiconductor integrated optical devices.

### Alumni

#### Co-op students:

• Arsam Golretz - 2015
• Amandeep Singh - 2014
• Norbert Feher - 2013—2014

• Jianzhou Wang (UROP program) - 2014

### Reseach

#### Integrated Photonic Circuits

The impact of photonics in our daily activities in the 21st century will undoubtedly surpass the influence of the “Electronics Age” of the past 60 years. Optical networks are transitioning from simple point-to-point arrangements to reconfigurable wavelength-routed architectures. The present role of large-scale photonic integration is to replace optical-to-electrical and back-to-optical (OEO) converters at the network nodes with single optical chips. Presently, signal processing at the network nodes is primarily performed electronically; however, photonic integration in optical communications will enable all-optical signal processing; thus minimizing the need for OEO at the network nodes. Remarkable progress in this direction has evolved in recent years. Numerous optoelectronic and all-optical functions have been demonstrated; among them are all-optical logic gates, label switching, analog-to-digital conversion, wavelength conversion, tunable optical delay lines, and 3R regeneration techniques. However, various all-optical signal processing operations and on-chip pulse metrology have not yet been demonstrated. The general goal of my research is to deal with these gaps, and to enable highly functional integrated photonic circuits for optical and quantum communications.

#### What is Integrated Photonic Circuit?

Have you ever seen an optical laboratory? Numerous optical components (mirrors, lenses) are arranged into an optical setup performing a certain function. The setup and a laser source are positioned on a large optical table. Now imagine down-scaling of the whole thing to a size of a $$1 \times 1$$ cm semiconductor chip without a loss of functionality. In such a way, the 8—12-ft-long table turns into a 1-cm-long chip, and all the bulk optical components and the laser source turn into micro-components written on the surface of the chip and performing the same functionalities.

The building blocks forming these micro-components are called integrated optical waveguides. Similar to optical fibres, they confine and guide light, in such a way controlling its flow on the chip. Design of the waveguide cross-section as well as the design and realization of various integrated optical components and functionalities constitute a large number of projects conducted in my group.

### All-Optical Signal Processing

All-optical signal processing operations rely predominantly on all-optical wavelength conversion, which can be implemented using nonlinear optical effects to modify the spectrum of the optical signal. These effects may be either second-order nonlinear interactions resulting in a sum-frequency generation followed by a difference-frequency generation (SFG/DFG) [L. Yan, et al., J. Lightwave Technol. 30, 3760 (2012)],

or third-order effects, such as cross-phase modulation (XPM) or four-wave mixing (FWM) [B. J. Eggleton, et al., Laser Photonics Rev. 6, 97 (2012)],

which rely on the intensity-dependent refractive index n2 (Kerr coefficient) [R. W. Boyd, “Nonlinear Optics,” 3rd ed., Acad. Press, 2008]. Among the material platforms and devices used for demonstrating wavelength conversion are lithium niobate [L. Yan, et al., J. Lightwave Technol. 30, 3760 (2012)], semiconductor optical amplifiers (SOAs) [C. Meuer, Opt. Express 19, 3788 (2011)], silicon [R. Salem, et al., Nature Photonics 2, 35 (2008)], chalcogenide glass [B. J. Eggleton, et al., Laser Photonics Rev. 6, 97 (2012)], and AlGaAs semiconductor passive waveguides [K. Dolgaleva, W. C. Ng, L. Qian, and J. S. Aitchison, Opt. Express 19, 12440 (2011), P. Apiratikul, et al., Opt. Express 22, 26814 (2014)]. Lithium niobate exhibits strong second-order nonlinearity and is suitable for wavelength conversion by SFG/DFG, whereas the rest of the materials have large Kerr coefficient values. However, silicon and SOA suffer from carrier dynamics that cause inter-channel cross-talk, limiting the operational speed of the devices. Additionally, fabrication of chalcogenide glass waveguides requires a sophisticated and expensive purification procedure. Only SOAs and AlGaAs can emit light and permit flexibility in terms of adjusting the operational wavelength of the waveguides. The materials involved belong to the class of III-V semiconductors. This class of materials features various compounds with tuneable optical properties, high nonlinear optical response, and the potentials of combining both active and passive devices on the same chip. Our group is working toward the realization of wavelength converters based on III-V semiconductors.

#### How does it all work…

Let’s consider the effect of four-wave mixing in its simplest form – when the frequencies of the two pump photons are identical: $$\omega_{\mathrm{p}1} = \omega_{\mathrm{p}2} \equiv \omega_{\mathrm{p}}$$. Technically, this means that we are using a single intensive pump beam that contributes two photons per each act of four-wave mixing. The signal beam frequency $$\omega_{\mathrm{s}}$$ is different from that of the pump. Its value dictates the value of the frequency of the generated idler beam $$\omega_{\mathrm{i}}$$. It is fixed by the relationship $$\omega_{\mathrm{i}} = 2\omega_{\mathrm{p}} - \omega_{\mathrm{s}}$$ that can be schematically represented by the following diagram.

### Wavelength Conversion

Let’s consider now a simple example that illustrates how the four-wave mixing effect can be used for wavelength conversion. We assume that a modulated laser beam of frequency $$\omega_{\mathrm{s}}$$ carries a bit stream of some information channel.

One can synchronize this beam with a non-modulated pulse stream

at a different frequency $$\omega_{\mathrm{p}}$$. Then the FWM interaction between the frequencies will result in the generation of the idler beam at the frequency $$\omega_{\mathrm{i}}$$ in the following fashion. Whenever the bit of the signal sequence is “1”, a “1” bit at $$\omega_{\mathrm{i}}$$ is generated. Whenever the bit of the signal channel is “0”, there is no radiation at $$\omega_{\mathrm{i}}$$, or “0” bit is generated. This could be understood as the logic “AND” gate: if we mix “1” with “0”, we’ll get “0”; if we mix “1” with “1”, we’ll get “1”. The outcome of this process is the replica of the original signal bit sequence, regenerated at the frequency of the idler (thus, “wavelength-converted” to a different frequency range). Applying filtering, one can transmit the idler frequency component, separating it from the residual signal and pump and obtaining the bit sequence at the new frequency.

### Optical Time Division Multiplexing

Let’s take a look at how four-wave mixing and the logic “AND” gate could be used to realize optical time-division multiplexing (OTDM). Consider, for example, three information channels at lower bit rates that need to be multiplexed into a single stream with a higher bit rate.

In order to do that, we use two extra non-modulated signals: one containing pulses at the same bit rate as the new bit rate of the multiplexed channels (“empty channel”), and another one with higher-power optical pulses for setting up a temporal frame (single bits of all three channels will fit between two consecutive framing pulses).

We would also need optical delay lines that could be realized, for example, with the use of optical fibre. Next we mix the non-modulated framing and high-bit-rate pulse streams with all three channels, delayed with respect to each other in such a way that the first bit of the first channel overlaps in time with one of the pulses of the high-bit-rate stream, the first bit of the second channel overlaps with the next (second) pulse of the high-bit-rate stream, the first bit of the third channel overlaps with the third pulse, and the fourth pulse overlaps with the framing pulse. The fifth pulse is then matched in time with the second bit of the first channel, and so on (see the diagram). Then the logic AND gate is realized in the process of the four-wave mixing. In such a way, we end up with a higher-bit-rate multiplexed channel bit stream where separate bit slots are divided by the framing pulses.

Using a similar approach, one can realize optical time division demultiplexing.

#### Photonic Crystal Devices

Wavelength demultiplexing has a large range of applications, including wavelength channel separation in communications, signal processing, and spectral analysis in lab-on-a-chip devices and optical sensors. The key characteristics essential to the performance of a demultiplexer include the footprint and resolution of the device, low insertion loss, low channel crosstalk, and simplicity of integration with other devices. Arrayed waveguide gratings (AWGs), which are essential components of modern integrated optical circuits, are extremely large because of their design features and principle of operation [B. Yang, et al., J. Lightwave Technol. 29, 2009 (2011)]. The first demonstration of the superprism effect [H. Kosaka, et al., Phys. Rev. B 58, R10096 (1998)] inspired attempts to develop demultiplexers based on photonic crystals [B. Momeni, et al., Opt. Express 14, 2413 (2006); A. Khorshidahmad and A. G. Kirk, Opt. Express 18, 20518 (2010); E. Cassan and M. Casale, J. Opt. Soc. Am. B 29, 1172 (2012)]. These are periodic dielectric structures with periodicity in the order of the optical wavelength [J. D. Joannopoulos, et al., “Photonic crystals: Molding the flow of light,” 2nd ed., Princeton University Press, 2008]. The picture below illustrates a combined action of the superprism effect, negative refraction, and negative dispersion, achievable in a certain frequency range in a photonic crystal device.

With many proposed designs of such devices, there are very few reports of their experimental demonstrations. One of the projects that we focus on is the design and experimental realization of a photonic crystal demultiplexer based on III-V semiconductors. It can be combined with wavelength converters to separate the wavelengths at their outputs, and also used as a part of optical pulse metrology on a chip.

#### Waveguide Cross-section Design

Waveguide is a building block of any integrated optical component. Proper design of the waveguide cross-section could ensure low propagation and nonlinear losses, single-mode operation, optimal light confinement, and enhanced nonlinear optical interaction. It is also possible to achieve dispersion management by a proper design of the waveguide dispersion. Depending on the specific goals we target, different waveguide designs could be necessary. Every device design thus begins with the design of the waveguide cross-section. Below is an example of our recent AlGaAs half-core-etched waveguide cross-section design, aimed at reaching a compromise between a larger (“strip-loaded”) and ultra-compact (“nanowire”) waveguide geometries.

#### Local-Field Effects and Nanostructured Materials

The optical response of a medium depends on the local field acting on an individual emitter rather than on the macroscopic average field in the medium. The local field depends very sensitively on the microscopic environment in an optical medium. It is thus possible to achieve a significant control over the local field by intermixing homogeneous materials on a nanoscale to produce composite optical materials. A combination of local-field effects and nanostructuring provides new degrees of freedom for manipulating the optical properties of photonic materials [ K. Dolgaleva and R. W. Boyd, Adv. Opt. Photon. 4, 1 (2012); K. Dolgaleva, Photonics and Nanostructures: Fundamentals and Applications 10, 369 (2012)]. Especially interesting opportunities open up in the nonlinear optical regime where the material response depends on the local-field correction as a power law. One of the directions of my research group focuses on studying the influence of local-field effects on the optical properties of photonic materials, both homogeneous and composite.

### Publications

2016

O. S. Maga~na-Loaiza, B. Gao, S. A. Schulz, K. M. Awan, J. Upham, K. Dolgaleva, and R. W. Boyd, "Enhanced spectral sensitivity of a chip-scale photonic-crystal slow-light interferometer," Optics Letters 41 (7), 1431-1434 (2016).

2015

K. Dolgaleva, P. Sarrafi, P. Kultavewuti, K. M. Awan, N. Feher, J. S. Aitchison, L. Qian, M. Volatier, R. Arès, and V. Aimez, "Tuneable four-wave mixing in AlGaAs nanowires," Optics Express 23 (17), 22477—22493 (2015).

K. Dolgaleva, D. V. Materikina, R. W. Boyd, and S. A. Kozlov, "Prediction of an extremely large nonlinear refractive index for crystals at terahertz frequencies," Physical Review A 92 (2), 023809 (2015).

K. M. Awan, S. A. Schulz, D. X. Liu, K. Dolgaleva, J. Upham, and R. W. Boyd, "Post-process wavelength tuning of silicon photonic crystal slow-light waveguides," Optics Letters 40 (9), 1952—1955 (2015).

2013

P. Sarrafi, E. Y. Zhu, K. Dolgaleva, B. M. Holmes, D. C. Hutchings, J. S. Aitchison, and L. Qian, "Continuous-wave quasi-phase-matched waveguide correlated photon pair source on a III-V chip," Applied Physics Letters 103 (25), 251115 (2013).

2012

K. Dolgaleva, "Modification of laser gain properties through local-field effects and nanostructuring," invited paper, Photonics and Nanostructures: Fundamentals and Applications 10 (4), 369—377 (2012).

K. Dolgaleva and R. W. Boyd, "Local-field effects in nanostructured photonic materials," invited paper, Advances in Optics and Photonics 4 (1), 1—77 (2012).

2011

Z. Shi, K. Dolgaleva, and R. W. Boyd, "Quantum noise properties of optical non-ideal amplifiers and attenuators," Journal of Optics 13 (12), 125201 (2011).

L. Caspani, D. Duchesne, K. Dolgaleva, S. Wagner, M. Ferrera, L. Razzari, A. Pasquazi, M. Peccianti, D. J. Moss, J. S. Aitchison, and R. Morandotti, "Optical frequency conversion in integrated devices," invited paper, Journal of the Optical Society of America B 28 (12), A67—A82 (2011).

K. Dolgaleva, A. Malacarne, P. Tannouri, L. A. Fernandes, R. J. Grenier, J. S. Aitchison, J. Azaña, R. Morandotti, P. R. Herman, and P. V. S. Marques, "Integrated optical temporal Fourier transformer based on chirped Bragg grating waveguide," Optics Letters 36 (22), 4416—4418 (2011).

K. Dolgaleva, W. C. Ng, L. Qian, and J. S. Aitchison, "Compact highly-nonlinear AlGaAs waveguides for efficient wavelength conversion," Optics Express 19 (13), 12440—12455 (2011).

2010

K. Dolgaleva, W. C. Ng, L. Qian, J. S. Aitchison, M. C. Camasta, and M. Sorel, "Broadband self-phase modulation, cross-phase modulation, and four-wave mixing in 9-mm-long AlGaAs waveguides," Optics Letters 35 (24), 4093—4095 (2010).

2009

K. Dolgaleva, H. Shin, and R. W. Boyd, "Observation of a microscopic cascaded contribution to the fifth-order nonlinear susceptibility," Physical Review Letters 103 (11), 113902 (2009).

S. N. Volkov, K. Dolgaleva, R. W. Boyd, K. Jefomovs, J. Turunen, Y. Svirko, B. K. Canfield, and M. Kauranen, "Optical activity in diffraction from a planar array of achiral nanoparticles," Physical Review A 79 (4), 043819 (2009).

S. K. H. Wei, S. H. Chen, K. Dolgaleva, S. G. Lukishova, and R. W. Boyd, "Robust organic lasers comprising glassy-cholesteric pentafluorene doped with a red-emitting oligofluorene," Applied Physical Letters 94 (4), 041111 (2009).

K. Dolgaleva, R. W. Boyd, and P. W. Milonni, "The effects of local field on laser gain for layered and Maxwell Garnett composite materials," invited paper, Journal of Optics A: Pure and Applied Optics 11 (2), 024002 (2009).

2008

K. Dolgaleva, S. K. H. Wei, S. G. Lukishova, S. H. Chen, K. Schwertz, and R. W. Boyd, "Enhanced laser performance of cholesteric liquid crystals doped with oligofluorene dye," Journal of the Optical Society of America B 25 (9), 1496—1504 (2008).

2007

K. Dolgaleva, R. W. Boyd, and J. E. Sipe, "Cascaded nonlinearity caused by local-field effects in the two-level atom," Physical Review A 76 (6), 063806 (2007).

K. Dolgaleva and R. W. Boyd, "Laser gain media based on nanocomposite materials," invited paper, Journal of the Optical Society of America B 24 (10), A19—A25 (2007).

K. Dolgaleva, R. W. Boyd, and P. W. Milonni, "Influence of local-field effects on the radiative lifetime of liquid suspensions of Nd:YAG nanoparticles," Journal of the Optical Society of America B 24 (3), 516—521 (2007).

L. Syrbu, V. V. Ursaki, I. M. Tiginyanu, K. Dolgaleva, and R. W. Boyd, "Red and green phosphoros prepared from porous GaAs templates," Journal of Optics A: Pure and Applied Optics 9 (4), 401—404 (2007).

L. Sirbu, V. V> Ursaki, I. M. Tiginyanu, K. Dolgaleva, and R. W. Boyd, "Er- and Eu-doped CaP-oxide porous composites for optoelectronic applications," Physica Status Solidi (RRL) - Rapid Research Letters 1 (1), R13—R15 (2007).

2005

P. P. Markowicz, V. K. S. Hsiao, H. Tiryaki, A. N. Cartwright, P. N. Prasad, K. Dolgaleva, N. N. Lepeshkin, and R. W. Boyd,"Enhancement of third-harmonic generation in a polymer-dispersed liquid-crystal grating," Applied Physics Letters 87 (5), 051102 (2005).

2000

V. G. Voronin, K. P. Dolgaleva, and O. E. Nanii, "Two-colour emission in a solid-state laser with a dispersive cavity," Quantum Electronics 30 (9), 778—782 (2000).