Monday, March 31, 2014

TOMORROW! IEEE Photonics Society student chapter Seminar: " The National Ignition Facility and the Pursuit of Star Power on Earth" by Dr. Christopher Barty 4.1.14/2:00-3:00pm/CREOL 102

IEEE Photonics Society student chapter Seminar: " The National Ignition Facility and the Pursuit of Star Power on Earth" by Dr. Christopher Barty
Tuesday, April 1, 2014 2:00 PM to 3:00 PM
CREOL Room 102


Dr. Christopher Barty
Lawrence Livermore National Laboratory

Abstract:
The National Ignition Facility at the Lawrence Livermore National Laboratory is the world's first mega-Joule laser and the first facility of its kind with sufficient laser energy to achieve controlled fusion ignition and burn in the laboratory, i.e. the same fusion process which powers our Sun.  This presentation will review the design, construction and development of NIF and its many technologies, the status of the 50+ year pursuit of inertial confinement fusion and the potential for laser inertial fusion energy as a source of clean, sustainable power. 

Biography:
Dr. C.P.J. Barty is the Chief Technology O?cer for the National Ignition Facility and Photon Science Directorate at the Lawrence Livermore National Laboratory. His academic background includes Ph.D. and M.S. degrees in applied physics from Stanford University and B.S. degrees, each with honors, in chemistry, physics, and chemical engineering from North Carolina State University. He has published more than 150 manuscripts and presented over 200 invited talks, spanning topics in lasers, optics, materials science, medicine, chemistry, engineering, and physics. He was elected a Fellow of the Optical Society of America for his pioneering work on intense short-pulse lasers and Xray applications. During his career, he has founded both the biennial international meeting on Ultrafast Optics and the International Conference on Ultrahigh Intensity Lasers. Currently, he is the Co-chair of the International Committee on Ultrahigh Intensity Lasers.

For more information:
IEEE Photonics Society Student Chapter Chair: Zhenyue Luo zhenyueluo AT creol . ucf . edu
IEEE Photonics Society Student Chapter Advisor: Prof.S.T.Wu  swu AT ucf . edu


Friday, March 28, 2014

TODAY! Get to Know Photonics at UCF: How Do Lasers Help Solve Crimes 3.28.14/3:00-4:00pm/ CREOL 102

Get to Know Photonics at UCF: How Do Lasers Help Solve Crimes
Friday, March 28, 2014 3:00 PM to 4:00 PM
CREOL Room 102


How do Lasers Solve Crimes- A crime is committed, glass is broken, and a suspect is arrested. But how do they know the suspect committed the crime? Find out how lasers are used to solve these mysteries!
Friday March 28, 3:00-4:00 pm, CREOL 102. Presented by Dr. Matthieu Baudelet, Research Assistant Professor, Secondary Joint appointment at the National Center for Forensic Science.
Part of the undergraduate Introduction to Photonics Seminar Series. Open to the public.


RSVP to Mike McKee at undergrad @ creol . ucf

Thursday, March 27, 2014

LighTimes: Researchers Develop Process to Make More Efficient and More Stable GaN-based LEDs

March 25, 2014...North Carolina State University Researchers found that coating gallium nitride (GaN) with a layer of phosphorous-derived acid can make LEDs that are both brighter and more resilient than traditional white LEDs.

“By coating polar GaN with a self-assembling layer of phosphonic groups, we were able to increase the luminescence without increasing energy input, ” says Stewart Wilkins, a Ph.D. student at NC State and lead author of a paper describing the work. “The phosphonic groups also improve stability, making the GaN less likely to degrade in solution."

The researchers began the process with polar GaN made up of alternating layers of gallium and nitrogen. They utilized phosphoric acid to etch the material's surface for increased luminescence, and they also added organic molecules containing phosphorous (phosphoric groups) that self-assembled into a monolayer on material's surface. This layer further increased luminescence and made it less likely to chemically react with its environment.

Making the GaN more stable is important, ” Wilkins added, “because that makes it more viable for use in biomedical applications, such as implantable sensors.”


The details of the development were published online in the journal Langmuir. The research was partially funded by the National Science Foundation under grant EEC 1156762.

Wednesday, March 26, 2014

TOMORROW! IEEE Photonics Society student chapter Seminar: "Can fibers replace all (most) lasers? ---Nonlinear Optics with Bessel Beams in Fibers" by Dr. Siddharth Ramachandran 3.27.14/2:00-3:00pm/ CREOL 102

IEEE Photonics Society student chapter Seminar: "Can fibers replace all (most) lasers? ---Nonlinear Optics with Bessel Beams in Fibers" by Dr. Siddharth Ramachandran
Thursday, March 27, 2014 2:00 PM to 3:00 PM
CREOL Room 102
Dr. Siddharth Ramachandran
Electrical Engineering Department, Boston University, Boston

Abstract:
Bessel beams have generated widespread interest over the last two decades because of intriguing properties such as their diffraction-resistant nature and the ability to navigate (self-heal) past opaque obstructions. In fibers, they exist as higher order modal solutions of the waveguide. While the fact that such beams theoretically exist in fibers is well-known from any waveguides textbook, only recently was it realised that, over lengths as long as 10-100 meters, beam stability in a fiber actually increases with mode order, for the sub-class of azimuthally symmetric fiber modes (i.e. for modes whose field is described by the J0 Bessel function).
This counter-intuitive finding has significant implications for mode area, and hence power scaling with optical fibers. More generally, and perhaps more interestingly, this results in the fiber as a nonlinear medium with dramatically enhanced degrees of freedom for phase matching. This talk will describe the physics of Bessel beam generation and propagation in fibers, and their implications for a novel degree of freedom in nonlinear topics, which lead to applications in fields as disparate as quantum-optics, deep-tissue imaging and high-power lasers.

Biography:
Dr Siddharth Ramachandran obtained his Ph.D. in Electrical Engineering from the University of Illinois, Urbana-Champaign, in 1998. Thereafter, he joined Bell Laboratories as a Member of Technical Staff and subsequently continued with its spin-off, OFS Laboratories. After a decade in industry, Dr. Ramachandran moved back to academics in 2010, and is now a Professor in the Department of Electrical Engineering at Boston University.
Prof. Ramachandran's research focuses on the optical physics of guided waves. He has authored over 200 refereed journal and conference publications, more than 45 invited talks, plenary lectures and tutorials, 3 book-chapters, edited one book, and has been granted 37 patents. For his contributions in the field of fiber-optics, he was named a Distinguished Member of Technical Staff at OFS Labs in 2003, a fellow of the Optical Society of America (OSA) in 2010, and an IEEE Distinguished Lecturer for 2013-2014. He served as a topical editor for Optics Letters from 2008-2011, and is currently an associate editor for the IEEE Journal of Quantum Electronics, in addition to serving on numerous conference and grant-review committees in the field of optics and applied physics.

For additional information:
IEEE Photonics Society Student Chapter Chair: Zhenyue Luo zhenyueluo @ creol . ucf . edu
IEEE Photonics Society Student Chapter Advisor: Prof.S.T.Wu swu @ ucf . edu


Monday, March 24, 2014

:Distinguished Speaker Series - Dr. Christos Papadimitriou


Physics Colloquium, Fri., Mar. 28, 2014, 4:30 PM, PSB 161

Dr. Thomas S. Statler
University of Maryland

Photon Rockets and Killer Asteroids: Radiation Recoil as an Evolutionary Driver in the Solar System

The recoil due to the reflection and emission of photons from a Sun-irradiated surface is a major driver of dynamical evolution for small asteroids—especially the sorts that pose an impact hazard for Earth. The net recoil force (the Yarkovsky effect) drives evolution of the orbital elements; the net recoil torque (the YORP effect) drives evolution of the spin rate and axis orientation. Both effects are sensitively dependent on the spin state; hence understanding how spins evolve under the influence of YORP is crucial for understanding how orbits evolve under the influence of Yarkovsky. Previous work showed that monolithic, rigid asteroids should follow a largely deterministic “YORP cycle,” with long phases of rotational acceleration and deceleration. I will demonstrate, however, that YORP is so hypersensitive to the detailed topography of the surface that slight motions of loose material can qualitatively alter the torque and interrupt the cycle. The fact that most asteroids are probably not monolithic, but instead loosely-bound aggregates, has led to suggestions that continuous YORP acceleration may drive centrifugal mass shedding and the formation of binaries. However, we have performed the first self-consistent simulations of the YORP effect on dynamically evolving aggregates, and the results indicate that acceleration is rarely continuous. Instead, repeated reconfigurations of the body under the changing centrifugal force result in a random walk in spin rate and obliquity. This stochastic YORP evolution is qualitatively different from the YORP cycle, and, moreover, correctly predicts the distribution of orbits for asteroid families evolving under the Yarkovsky effect. These results have significant implications for binary formation and the feeding of asteroids onto Earth-crossing orbits, as well as for our understanding of the material properties of potential impactors.


Wednesday, March 19, 2014

IEEE Photonics Society student chapter Seminar: " The National Ignition Facility and the Pursuit of Star Power on Earth" by Dr. Christopher Barty /4.1.14/2:00-3:00pm/CREOL 102

IEEE Photonics Society Student Chapter Seminar: " The National Ignition Facility and the Pursuit of Star Power on Earth" by Dr. Christopher Barty
Tuesday, April 1, 2014 2:00 PM to 3:00 PM
CREOL Room 102


Dr. Christopher Barty
Lawrence Livermore National Laboratory

Abstract:
The National Ignition Facility at the Lawrence Livermore National Laboratory is the world's first mega-Joule laser and the first facility of its kind with sufficient laser energy to achieve controlled fusion ignition and burn in the laboratory, i.e. the same fusion process which powers our Sun.  This presentation will review the design, construction and development of NIF and its many technologies, the status of the 50+ year pursuit of inertial confinement fusion and the potential for laser inertial fusion energy as a source of clean, sustainable power. 
Biography:
Dr. C.P.J. Barty is the Chief Technology O?cer for the National Ignition Facility and Photon Science Directorate at the Lawrence Livermore National Laboratory. His academic background includes Ph.D. and M.S. degrees in applied physics from Stanford University and B.S. degrees, each with honors, in chemistry, physics, and chemical engineering from North Carolina State University. He has published more than 150 manuscripts and presented over 200 invited talks, spanning topics in lasers, optics, materials science, medicine, chemistry, engineering, and physics. He was elected a Fellow of the Optical Society of America for his pioneering work on intense short-pulse lasers and Xray applications. During his career, he has founded both the biennial international meeting on Ultrafast Optics and the International Conference on Ultrahigh Intensity Lasers. Currently, he is the Co-chair of the International Committee on Ultrahigh Intensity Lasers.

For more information:
IEEE Photonics Society Student Chapter Chair: Zhenyue Luo zhenyueluo @ c reol . ucf . edu
IEEE Photonics Society Student Chapter Advisor: Prof.S.T.Wu  swu @ ucf . edu


Tuesday, March 18, 2014

CANCELED!! Distinguished Seminar Series: "Nonlinear optics at the nanoscale" by Eric Mazur 3.18.14/11:00am-12:00pm/ CREOL Room 102

This event has been canceled. We will let you know once it has been rescheduled.


Distinguished Seminar Series: "Nonlinear optics at the nanoscale" by Eric Mazur

Tuesday, March 18, 2014 11:00 AM to 12:00 PM
CREOL Room 102

Eric Mazur
Harvard University
Area Dean of Applied Physics

Abstract:
We explore nonlinear optical phenomena at the nanoscale by launching femtosecond laser pulses into long silica nanowires. Using evanescent coupling between wires we demonstrate a number of nanophotonic devices. At high intensity the nanowires produce a strong supercontinuum over short interaction lengths (less than 20 mm) and at a very low energy threshold (about 1 nJ), making them ideal sources of coherent white-light for nanophotonic applications. The spectral broadening reveals an optimal fiber diameter to enhance nonlinear effects with minimal dispersion. We also present a device that permits a number of all-optical logic operations with femtosecond laser pulses in the nanojoule range.

Biography:
Eric Mazur is the Balkanski Professor of Physics and Applied Physics at Harvard University and Dean of Applied Physics. He is a prominent physicist known for his contributions in nano photonics, an internationally recognized educational innovator, a sought-after lecturer, and successful entrepreneur. In education he is widely known for his work on Peer Instruction, an interactive teaching method aimed at engaging students in the classroom and beyond. Mazur has received many awards for his work in physics and in education and has founded several successful companies. Mazur is Chief Academic Advisor for Turning Technologies, a company developing interactive response systems for the education market. Dr. Mazur is author or co-author of 258 scientific publications and 23 patents. He has also written extensively on education and is the author of Peer Instruction: A User's Manual (Prentice Hall, 1997), a book that explains how to teach large lecture classes interactively. In 2006 he helped produce the award-winning DVD Interactive Teaching.


Monday, March 17, 2014

Get to Know Photonics at UCF: How Do Lasers Help Solve Crimes

To:  Florida Photonics Cluster member
Below is information on a seminar at CREOL that you or some of your colleagues might be interested in attending.

Jim Pearson
FPC Executive Director
************************************

            Get to Know Photonics at UCF: How Do Lasers Help Solve Crimes

Friday, March 28, 2014 3:00 PM to 4:00 PM
CREOL Room 102
How do Lasers Solve Crimes- A crime is committed, glass is broken, and a suspect is arrested. But how do they know the suspect committed the crime? Find out how lasers are used to solve these mysteries!
Friday March 28, 3:00-4:00 pm, CREOL 102. Presented by Dr. Matthieu Baudelet, Research Assistant Professor, Secondary Joint appointment at the National Center for Forensic Science.
Part of the undergraduate Introduction to PhotonicsSeminar SeriesOpen to the public.
RSVP to Mike McKee at undergrad @ creol . ucf . edu

Friday, March 14, 2014

CANCELED!! Distinguished Seminar Series: "Nonlinear optics at the nanoscale" by Eric Mazur 3.18.14/11:00am-12:00pm/ CREOL Room 102

This event has been canceled. We will let you know once it has been rescheduled.


Distinguished Seminar Series: "Nonlinear optics at the nanoscale" by Eric Mazur

Tuesday, March 18, 2014 11:00 AM to 12:00 PM
CREOL Room 102

Eric Mazur
Harvard University
Area Dean of Applied Physics

Abstract:
We explore nonlinear optical phenomena at the nanoscale by launching femtosecond laser pulses into long silica nanowires. Using evanescent coupling between wires we demonstrate a number of nanophotonic devices. At high intensity the nanowires produce a strong supercontinuum over short interaction lengths (less than 20 mm) and at a very low energy threshold (about 1 nJ), making them ideal sources of coherent white-light for nanophotonic applications. The spectral broadening reveals an optimal fiber diameter to enhance nonlinear effects with minimal dispersion. We also present a device that permits a number of all-optical logic operations with femtosecond laser pulses in the nanojoule range.

Biography:
Eric Mazur is the Balkanski Professor of Physics and Applied Physics at Harvard University and Dean of Applied Physics. He is a prominent physicist known for his contributions in nano photonics, an internationally recognized educational innovator, a sought-after lecturer, and successful entrepreneur. In education he is widely known for his work on Peer Instruction, an interactive teaching method aimed at engaging students in the classroom and beyond. Mazur has received many awards for his work in physics and in education and has founded several successful companies. Mazur is Chief Academic Advisor for Turning Technologies, a company developing interactive response systems for the education market. Dr. Mazur is author or co-author of 258 scientific publications and 23 patents. He has also written extensively on education and is the author of Peer Instruction: A User's Manual (Prentice Hall, 1997), a book that explains how to teach large lecture classes interactively. In 2006 he helped produce the award-winning DVD Interactive Teaching.

For additional information:
Dr. Bahaa E. A. Saleh
Dean & Director, Professor of Optics
407-882-3326
besaleh @ creo l . ucf . edu

Thursday, March 13, 2014

Microgravity Experiments On The First Steps of Planet Formation

Florida Space Institute Seminar Announcement

Speaker: Julie Brisset
Affiliation: University of Braunschweig, Germany
Day and Date: Wednesday, March 19, 2014
Time: 2:00 – 3:00 pm

Location: Partnership 1, Research Parkway
Building 8111, Orlando, Florida
Room 209
Title    
Title : Microgravity Experiments On The First Steps of Planet Formation
Abstract :
In the very first steps of planet formation, dust particles inside the protoplanetary disk collide with each other and grow from micrometer sizes to aggregates of a few centimeters. In order to investigate the dust collision behavior at low velocities, the SPACE (Suborbital Particle Aggregation and Collision Experiment) set-up was flown at the drop tower in Bremen, Germany (9 s of microgravity time), and on the REXUS 12 suborbital rocket from Kiruna, Sweden (170 s of microgravity time). The results of these experiments allowed for the measurement of critical collision properties of sub-mm-sized dust aggregates, especially in the transition regimes between sticking, bouncing and fragmentation. In particular, the formation and characteristics of clusters composed of a high number of aggregates were observed and yielded relevant information for future protoplanetary disk simulations.

For further information please click below:

Wednesday, March 12, 2014

TODAY! Seminar: "Femtosecond laser filamentation in air: the roles of optical nonlinearity and plasma generation" by Dr. Yu-hsin Chen 3.12.14/11:00am-12:00pm/CREOL 102

Seminar: "Femtosecond laser filamentation in air: the roles of optical nonlinearity and plasma generation" by Dr. Yu-hsin Chen
Wednesday, March 12, 2014 11:00 AM to 12:00 PM
CREOL Room 102

Dr. Yu-hsin Chen

Abstract:
An intense femtosecond laser pulse propagating in a gas may collapse into one or multiple “filaments” when its peak power exceeds the critical power (5 – 10 GW in air) for nonlinear self-focusing. In atmosphere, the laser intensity is typically ~ 1013 W/cm2 in the filament, leaving a weakly-ionized plasma channel which can extend meters in length with a diameter of < 100 μm. While it has been generally accepted that laser filamentation is the consequence of self-focusing-induced beam collapse stabilized by plasma generation and de-focusing, neither the field-induced nonlinearity nor the plasma generation had been directly measured. This uncertainty has given rise to recent controversy about whether plasma generation does indeed counteract the positive nonlinearity, as an alternate theory suggests that the stabilization mechanism is contributed by saturation of optical nonlinearity.
For a basic understanding of femtosecond filamentation and for applications, the focusing and defocusing mechanisms – nonlinear self-focusing and ionization – must be understood. By employing a single-shot, time-resolved technique based on spectral interferometry to study the constituents of air, it is found that the rotational responses in O2 and N2 are the dominant nonlinear effect in filamentary propagation when the laser pulse duration is longer than ~ 100 fs. Furthermore, we find that the instantaneous nonlinearity scales linearly up to the ionization threshold, suggesting that an ionization-free, negative stabilization of filamentation does not exist. This is confirmed by space-resolved plasma density measurements in meter-long filaments using optical interferometry with a grazing-incidence probe laser pulse.

Biography:
Dr. Yu-hsin Chen received the B.S. degree in electrical engineering and the M.S. in electro-optical engineering in 2000 and 2002, respectively, both from National Taiwan University. He obtained his Ph.D. degree in electrical engineering from University of Maryland, College Park in 2011. Then he worked as a postdoctoral researcher at Lawrence Livermore National Laboratory.
Dr. Chen’s research interests are in ultrafast lasers, nonlinear optics, high-intensity laser-plasma interactions, and laser acceleration of charged particles. He has won 2012 Marshall N. Rosenbluth Outstanding Doctoral Thesis Award in plasma physics, for his work on femtosecond laser filamentation in atmosphere.

For additional information:
Dr. Martin C. Richardson
Pegasus Professor and University Trustee Chair, Northrop Grumman Prof of X-ray Photonics; Prof of Optics; Director Townes Laser Institute
407-823-6819

mcr @ creol. ucf . edu

Monday, March 10, 2014

TOMORROW! Seminar: "Characterization of ultra-short pulsed laser damage in optical crystals by interferometry and photoelectron spectroscopy experiments" by Sergey Klimentov 3.11.14/11:00am-12:00pm/CREOL 102

Seminar: "Characterization of ultra-short pulsed laser damage in optical crystals by interferometry and photoelectron spectroscopy experiments" by Sergey Klimentov
Tuesday, March 11, 2014 11:00 AM to 12:00 PM
CREOL Room 102

Sergey Klimentov
General Physics Institute of
Russian Academy of Sciences

Abstract:
Optical energy deposition and relaxation in wide-band gap crystals (oxides and halides) was investigated aiming to determine processes in charge of laser breakdown induced by IR femto- and picosecond laser pulses. In situ monitoring of electron concentrations around the damage threshold was performed using ultra-fast interferometry, while their energy was estimated in photo-electron spectroscopy experiment. In both cases, the same spot on the surface was exposed to a couple of laser pulses with variable time delay (UV followed by IR after-exposure) to distinguish stages of conduction band populating and the following heating of free electrons with possibility of impact ionization. Breakdown threshold were measured in the same conditions. This way, the most complete, direct and detailed set of measurements was performed to characterize electron multiplication and laser damage in these materials.
In spite of the similar damage dependences and significant energy of free electrons (> 20-30 eV) observed in all the materials far below the damage threshold, impact ionization was only observed in those known to bind the free electrons within self-trapped exitons (SiO2, NaCl). Oxides of Al and Mg did not reveal multiplication of electrons in spite of their long lifetime in the conduction band, were their energy seemed to be directly transferred to heat via electron-phonon coupling. Variation of energy of the IR heating pulse allowed to show, that achieving of critical electron density, used as conventional criterion of optical damage, is not valid in the case of both groups of materials.

For additional information:
Dr. M.J. Soileau
V.P. for Research and Professor of Optics, ECE & Physics
407-823-5538

MJ . Soileau @ ucf . edu