Engineering robust solid-state quantum systems is amongst the most pressing challenges to realize scalable quantum photonic circuitry. While several 3D systems (such as diamond or silicon carbide) have been thoroughly studied, solid state emitters in two dimensional (2D) materials are still in their infancy. In this presentation I will discuss single defects in an emerging 2D material – hexagonal boron nitride (hBN), that is promising as qubits for quantum photonic applications. In particular, I will focus on ways to engineer these defects deterministically using either chemical vapour deposition growth or ion implantation, and show results on strain tuning of these ultra-bright quantum emitters. I will then highlight promising avenues to integrate the single defects with photonic cavities, as a first step towards integrated quantum photonics with 2D materials. I will summarize by outlining challenges and promising directions in the field of quantum emitters and nanophotonics with 2D materials.

Watch the recorded lecture from April 23, 2020:

The electrical power consumed in data transmission systems is now hampering efforts to further increase speed and capacity at various scales, ranging from data centers to microprocessors. Optical interconnects employing ultra-low-energy directly-modulated lasers will play a key role in reducing the power consumption. Since a laser's operating energy is proportional to the size of its active volume, developing high-performance laser with a small cavity is important. For this purpose, we have developed DFB and photonic crystal (PhC) lasers, in which active regions are buried with an InP layer. Thanks to the reduction of cavity size and the increase in optical confinement factor, we have achieved an extremely small operating energy of 4.4 fJ/bit by employing a wavelength-scale PhC cavity. Cost reduction is also an important issue because a larger number of transmitters are required for short-distance optical links. For this purpose, Si photonics technology is expected to be a potential solution because it can provide large-scale photonic integrated circuits (PICs). Therefore, heterogeneous integration of III-V compound semiconductors and Si has attracted much attention. To fabricate these devices, we have developed wafer-scale fabrication  that employs regrowth of III-V compound semiconductors on directly-bonded thin InP templates on an SiO2/Si substrate. 

​NASA’s trend toward less costly missions has created a need for smaller and more capable instruments for in situ planetary applications, space weather, and Earth Observations. The rise of cubesats has created a new powerful platform that if enabled with powerful sensing technology can be an instrument of discovery. At the same time, large aperture UV/visible/Near Infrared space telescope are being planned for cosmology and astrophysics studies that will need high performance yet affordable detectors to populate their very large focal plane arrays. In nearly all these facets of space exploration, there is a strong need for high signal to noise ultraviolet detection technology. This is due to the fact that the ultraviolet part of the spectrum is rich in spectral information that are key to study exo-solar planets, protoplanets, intergalactic medium, supernovae, electromagnetic counterpart of gravitational wave, star formation, galaxy evolution, and more. Semiconductor detectors offer a rich spectral range, tailorable spectral response, high resolution, and sensitivity; however, these capabilities are not available in a single material or class of material. For example, while silicon imagers have reached high performance levels in format, pixel size, and signal to noise, they are naturally insensitive to ultraviolet light. Using non-equilibrium processes, we can manipulate materials at nanometer scale, form unusual and quantum structures, and alter bandstructures. Through nanoscale surface and interface engineering of 2D doping (superlattice doping and delta doping) high performance silicon-based imagers are produced with record high quantum efficiency in the ultraviolet. Furthermore, the response of silicon imagers can be tailored for out of band rejection through nano-scale interface engineering. In this talk we will discuss the underlying physics of the ultraviolet silicon detectors, their performance, their integration in systems, and their application in cubesats and space flagship missions. We will also discuss the synergy between the requirements for instruments in NASA space applications and medical applications and show how space technologies can and have been used for medical applications.

Come and mingle for any sessions during the first all-online photonics conference, the Photonics Online Meetup (POM). The event will be continuously live-streamed between 11am and 4pm in Elings 1605. Refreshments will be served.
The conference will feature internationally renowned scientists as plenary speakers:

• Prof. Mete Atature (University of Cambridge, UK)
• Prof. Nader Engheta (University of Pennsylvania, USA)
• Prof. Mercedeh Khajavikhan (CREOL-University of Central Florida, USA)

The complete program can be found here:
https://sites.usc.edu/pom/program/

Abstract: Graphene has emerged as an alternative saturable absorber to other semiconductors due to its nearly constant broadband absorption of 2.3%. It has been shown that graphene and graphene-based nanomaterials can be used as efficient saturable absorbers to generate ultrashort pulses from lasers operating in the near- and mid-infrared. However, the 2.3% absorption of the monolayer graphene introduces operational challenges to the lasers with low gains. To obviate such challenges, the Fermi level position of the graphene can be varied to control the amount of absorption at the desired wavelength. For this purpose, chemically- or electrostatically-doped novel graphene architectures with reduced optical insertion losses can be used to optimize the power performance of the femtosecond lasers.

In this talk, the use of carbon-based saturable absorbers to generate ultrashort pulses from solid-state lasers will be presented and their current drawbacks will be discussed. This will be followed by the overview of the possible approaches, which have been demonstrated to shift the Fermi level of graphene to control the amount of absorption at the desired wavelength. At this point, the voltage-controlled graphene-based supercapacitor architectures proposed by our groups will be demonstrated and the femtosecond pulse generation results obtained with these devices will be discussed.

In the remainder part of the talk, Dr. Baylam will give information about the opportunities provided by The Optical Society (OSA) to the graduate students and early career researchers.

Prof. Armani is the head of a research lab at USC where she "develops advanced materials and integrated optical devices that can be used in portable disease diagnostics and telecommunications." Read more about her research at https://armani.usc.edu/. 

Nanomateial-Enhanced Integrated Photonics
Abstract: Integrated photonics offers a potential alternative to integrated electronics, with reduced heating and faster data rates. However, to achieve many of the desired performance metrics, it is necessary to combine disparate material systems. Heterogeneous integration is plagued by challenges, including different lattice constants, thermal expansion coefficients, and fabrication compatibilities, all of which can impact the final device performance ad lifetime. Therefore, new materials and material systems as well as fabrication methods are desired. One approach is to combine the conventional top-down fabrication methods and optical materials, such as silica and silicon, with bottom-up fabrication and nano-materials. These hybrid systems provide access to optical behavior and performance not attainable with conventional approaches. This talk will present several of the new integrated hybrid photonic devices being developed in the Armani Lab, including approaches based on nonlinear organic small molecules and plasmonic nanoparticles to develop Raman lasers and frequency combs.

Grade 6+ ONLY
Proof of U.S. Persons required:
ALL tour attendees must bring ONE of the following IDs:
(1) U.S. Passport
(2) U.S. Naturalization Certificate
(3) Permanent Resident/Green Card
(4) U.S. Birth Certificate AND either Photo ID or Social Security card
Note: For parents or chaperones, a driver's license is NOT valid proof. Yes, even children need this proof.

Megan Birney is President of Unite to Light, a nonprofit organization that manufactures and distributes solar lights to people living without access to electricity across the globe.
Throughout her career Megan has focused on increasing access to clean, renewable energy. She started her career at the Community Environmental Council where she ran the Energy Efficiency and Renewable Energy Programs, including creation of Solarize, a residential group-purchasing program in California. While there she advocated for renewable energy projects and policies leading to over 1 GW of solar in the Central California region.  Then Megan served as Director of Strategic Affairs and Product Manager for a commercial solar financing company that was aiming to address the financing gap for nonprofits and small businesses. Megan is also a Water Commissioner for the City of Santa Barbara. She has a Masters in Public Policy from the University of Southern California, and a BA in Sociology from the University of California, San Diego. Megan has taught a courses on energy sources, uses and issues through the University of California extension program. 

Photonics and Global Aid & Development: the Power of Solar Lights
Unite to Light, a nonprofit founded at UCSB, manufactures and distributes solar lights and solar power to people living without electricity. Hear from President & CEO Megan Birney about how the organization was founded, the innovation of their lights, and the impact around the world.