Tuesday, September 8th, 10 am (PDT) via Zoom
Meeting ID: 978 3569 2970 Passcode: 468555
Infectious diseases and water are some of the greatest, most urgent challenges of the 21st century. III-nitride ultraviolet (UV) light sources, including light emitting diodes (LEDs) and lasers, are the only alternative technology to replace conventional power-hungry, hazardous mercury lamps for disinfection and water purification. Recent studies showed that AlGaN-based UV-C LEDs can readily shred genetic material of viruses and bacterial and achieve 99.9% sterilization of SARS-COV-2. In this talk, I will present the recent advances of AlGaN and BN nanostructures and heterostructures and their applications in UV optoelectronics, including the first demonstration of mid and deep UV laser diodes and tunnel junction UV-C LEDs with significantly improved performance. The recent development of far-UV-C LEDs, in the wavelength range of 207-222 nm, will also be presented, which has shown to be faster and far more effective than traditional UV-C light (~265 nm) in preventing the transmission of microbial diseases, while causing virtually no harm to mammalian skin or eye.
Wednesday, May 20, 2020, 1 p.m.
Sustainability applied to networking is about treating professional support and assistance like a resource, and creating more of it than you take. Dr. Willis will discuss principles and applications of sustainable professional networking, and how to use it to generate success through mutually beneficial professional relationships. She will also discuss her own career path, citing examples that illustrate the value of sustainable networking.
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:
12:00 - 1:00 PM Friday, February 21st in Engineering II 3519
Friday, Feb 14th from 12:00 - 1:00 pm in Elings 1601
Friday, February 7th from 12:00 - 1:00 pm in ESB 2001
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.
Thursday, January 30th, 11 am, Elings 1605
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.
Blue Semipolar III-Nitride Vertical-Cavity Surface-Emitting Lasers
Friday, January 24th | 12:00 pm | ESB 2001
Pizza will be provided!
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:
Thurs. Nov 14, 2019 | 12:00 - 1:00 pm | ESB 2001
Photonic technologies are at the forefront of the ongoing 4th industrial revolution of digitalization supporting applications such as virtual reality, autonomous vehicles, and electronic warfare. The development of integrated photonics in recent years enabled functional devices and circuits through miniaturization. However, fundamental challenges such as the weak light-matter integration can limited silicon and III-Vbased devices to millimeter-scale footprints demanding about one million photons-per-bit. Overcoming these challenges, in the first part of this talk I will show how nanoscale photonics together with heterogeneous integration of emerging materials into foundry-based photonic chips enables strong nonlinearity, which we use to demonstrate attojoule and compact optoelectronics. Here I will discuss our recent devices demonstrating ITO-based MZI modulators, 2D-material excitonic photodetectors, and exotic epsilon-near-zero modes empowering record-efficient phase shifters for applications in data-comm, LiDAR, and photonic neural networks (NN). Further, I will show that the usually parasitic Kramers-Kronig relations of altering the optical index can be synergistically exploited delivering new modulator operations. With Moore’s law and Dennard scaling now being limited by fundamental physics, the trend in processor heterogeneity suggests the possibility for special-purpose photonic processors such as NNs or RF-signal & image filtering. Here unique opportunities exist, for example, given by algorithmic parallelism of analog computing enabling non-iterative O(1) processors, thus opening prospects for distributed nonvan Neumann architectures. In the second part of this talk, I will share our latest work on analog photonic processors to include a) a feed-forward fully-connected NN, b) mirror symmetry perception via coincidence detection of spiking NNs, c) a Fourier-optics based convolutional processor with 1 PMAC/s throughputs at nanosecond-short delays for real-time processing, d) a photonic residue arithmetic adder, and e) meshbased reconfigurable photonic & metatronic PDE solvers. In summary, heterogeneous photonics connects the worlds of electronics and optics, thus enabling new classes of efficient optoelectronics and analog processors by employing the distinctive properties of light.
Pizza will be provided!
Wednesday, July 31 | 12:00pm | ESB 2001
Photonic Integration for RF Photonics Systems Photonic integration on the Silicon Photonics platform, together with heterogeneous integration to include other materials, provides an ideal platform for the development of complex photonic integrated circuit (PIC) devices. This talk will describe the requirements for basic RF Photonics systems, including low noise lasers, linear modulators, low loss optical processing elements, and high power photodetectors, followed by descriptions of devices and PICs that Morton Photonics is developing for these functions.
The talk will describe how a high performance PIC including arrays of these devices can be utilized for the processing of a phased array sensor to provide Multiple-Channel Simultaneous RF Beamforming, and describe potential commercial markets for these technologies, including automotive LIDAR systems, analog photonic links and RF Beamforming for 5G systems
Friday, June 7th | 12:00pm | Elings 1605
The 3rd Santa Barbara Photonics Banquet took place on:
Tuesday June 4th, 6pm at Corwin Pavilion @ UCSB
See the event page for more info:
SB Photonics Banquet 2019
Friday, May 31st | 12:00 pm | Elings 1605
Friday, May 17th | 12:00 pm | ESB 2001
Fluency Lighting Technologies is an early stage start-up company developing technology out of UC Santa Barbara. At Fluency, we are creating next-generation bright and narrow-beam light sources for highly efficient illumination, using laser technology and materials design. Our focus is the development of low-cost, optical platforms that convert laser diode emission into high-quality white light in various light levels, beam angles, and color temperatures, designed for customer-driven metrics, in applications where energy-saving LED technology is not used because of the limited light output from an LED.
Refreshments will be provided
Thursday, May 16th | 12:00 pm | Elings 1601
In recent years, widely tunable micro-electro-mechanical systems vertical cavity surface-emitting lasers (MEMS-VCSELs) have found commercial application in swept source optical coherence tomography medical imaging and also show considerable promise in metrology and spectroscopy. These devices exhibit fractional tuning ranges of >11% of the center wavelength, wavelength tuning repetition rates over full tuning range of >1MHz, and clean single-mode operation. These properties, in conjunction with small size and wafer scale fabrication and testing, promise an economical optical source that can impact sensing applications from the visible to the mid-infrared.
Refreshments will be provided
Wednesday, May 15th | 12:00 pm | ESB 1001
In this talk I will highlight the history of GaN research at UCSB, and some of the key breakthroughs and technologies developed by the faculty, students and staff. Starting with one MOCVD system, UCSB Faculty were the first University world-wide to achieve a blue GaN Laser in 1996. In 2000, Prof. Shuji Nakamura joined the Faculty and along with Prof. DenBaars, Prof. Speck and Prof. Mishra co-founded the Solid State Lighting and Energy Electronics Center (SSLEEC), which has now become one of the largest academic GaN based Photonic and Electronic research centers in the world. SSLEEC has played a key role in developing numerous breakthroughs, some of which have led to the realization of high-efficiency Solid-State Lighting, which the Dept. of Energy estimates will save the equivalent annual electrical output of about fifty 1,000-megawatt power plants.
Looking into the future we see next generation GaN Laser Diode based solid state lighting as impacting high brightness specialty lighting. We have demonstrated laser based white lighting with luminous efficacies of 87 lm/watt, and over 1000 lumens from a single emitter. In addition, tunnel junctions have been employed to achieve vertical cavity surface emitting lasers (VCSELs) in the blue spectral region. Blue and green lasers and Micro-LEDs based on GaN materials are expected to enable new full color projections displays for cinema, office and augmented reality (AR) applications.
Refreshments will be provided
Thursday, May 9th | 12:00 pm | Elings 1601
Chris will discuss next-generation optical interfaces for large scale datacenters, including Intensity Modulated Direct Detection and Coherent technologies at 100, 200, 400 and 800 Gb/s rates. He will show several examples of how applying insights gained from previously successful applications can lead to flawed conclusions about different applications. If he is persuasive, students will no longer trust what they are taught by their professors and other experts.
Friday, May 3 | 12:00pm | Elings 1605
Pizza will be provided!