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
Friday, May 10th | 12:00pm | Elings 1605
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!
Friday April 26th | 12:00 pm | Elings 1605
Two-dimensional Van der Waals materials have emerged as a very attractive class of optoelectronic material due to the unprecedented strength in its interaction with light. In this talk I will discuss approaches to realize quantum photonic devices by integrating these 2D materials with microcavities, and metamaterials. I will first discuss the formation of strongly coupled half-light half-matter quasiparticles (microcavity polaritons) and their optical and electrical control in the 2D transition metal dichacogenide (TMD) systems. Prospects of realizing condensation and few photon nonlinear switches using Rydberg states in TMDs will also be discussed. Following this, I will discuss the broadband enhancement of light-matter interaction in these 2D materials using photonic hypercrystals and chiral metasurfaces. Finally, I will talk about room temperature single photon emission from hexagonal boron nitride and the prospects of developing deterministic quantum emitters using them through strain engineering. The realization of room temperature single photon emitters and few photon
nonlinear switches using 2D materials presents an attractive direction for robust next generation quantum photonic technologies.
Tuesday, April 23rd | 12:00 pm | Elings 1601
Today zettabytes of data are generated and nearly doubled every two years. The conventional microprocessor is reaching its physical limitation and cannot keep up with the exponential growth in rich data. This leads to the increased demands on memory systems due to their frequent access patterns between microprocessors and memories. High speed, low energy and high sensitive optical data links are desirable for data transmission between multicores, microprocessors and memories in the new data center and high performance computer architectures. I am going to talk about the silicon photonics efforts in developing low energy high speed optical links in Hewlett Packard Labs, including the development of low voltage SiGe avalanche photodiodes, as well as photonic links.
Monday, April 15 | 12:00pm | Elings 1605
Think small: developing color centers in crystals for nanoscale optical sensors of fields and forces
Friday, April 12 | 12:00pm | Elings 1605
From mapping inter-cellular mechanical interactions in the immune system to imaging magnetic phenomena in condensed matter systems, there is a growing need for noninvasive sensors with high spatial resolution. Color centers in crystals such as alkaline-earth upconverting nanoparticles (UCNPs) and the nitrogenvacancy (NV) center in diamond are an exciting class of sensors for highresolution imaging because of their optical readout, nanoscale size, and robust hosts. The first part of this talk will discuss UCNPs for mechanical force sensing in biological applications. UCNPs consist of a ceramic host doped with lanthanides (Yb3+ and Er3+). They operate by absorbing low energy infrared photons and emitting higher energy visible photons. Mechanical forces cause a change in the crystal symmetry and spacing of the dopant atoms, which results in a change of emission intensity and color. We have recently detected 27 nN forces with our UCNPs, a requisite for detecting inter-cellular forces in the immune system. The second half of this talk will discuss using the NV center in diamond as a magnetic force sensor. Through careful materials science studies in the Jayich lab, we created NV ensembles approaching the NV dipolar interaction limit of sensitivity. Using these NV ensembles, we imaged magnetic structure in CoTiSb.