7/22 Summer Colloquium Speaker Announcement

leidner_jordanOn Tuesday, July 22nd the UR SPIE student chapter will be continuing its Summer Colloquium series with a double header! Please bring your lunch and come listen to our next presentation! Snacks and beverages will be provided.

Speaker 1: Jordan Leidner
What:
Filamentation-Free Broad-Area Laser Design for Efficient Coupling to Single-Mode Fiber
Abstract:Although the quest for high-power, diffraction-limited, semiconductor lasers has arguably met with limited success, the drive for higher brightness diode lasers continues, driven by fiber laser systems.  Using tailored refractive-index and injection-current profiles, broad-area laser Beam Propagation Method simulations predict simultaneous suppression of free-carrier-induced self-focusing and far-field mode compression at high powers.  Asymmetric gain from tailored current profiles generate unconventional, null-less modes and lead to distributed gain- and loss-filtering mechanisms for increased beam quality output.  5.2-7.7W of spatiotemporally stable (filamentation-free) power enables high-efficiency (70%) coupling into SMF-28, resulting in 3.1-5.5W of fiber-coupled power for EDFA pumping with 0.72 W/A slope efficiency.  The concept is shown to be robust against the shape of the profiles, inhomogeneities in both injection current and refractive index, and thermal lensing with proper sub-mount design.

DSC06993Speaker 2:
Katelynn Sharma
What:  Measurement of spatial coherence through the shadows of small obscurations
Abstract:We present a simple method to measure the spatial coherence of a partially coherent field by analyzing measurements of the radiant intensity with and without a small, well-characterized obscuration. From these measurements, the coherence of a field can be estimated simultaneously for all pairs of points whose centroid is the same as that of the obstacle. By scanning the obstacle over the test plane, one can recover the full four-dimensional coherence function. In principle, such measurements can be performed without any refractive or diffractive elements, allowing for measurements to be done in higher frequency regimes. In the experimental results presented here, however, the radiant intensity was measured at the back-focal plane of a lens. Our results are highly consistent with theoretical predictions for obscurations whose size is on the order of the coherence width of the source.

When: 7/22/2014  11:30 am – 12:30 pmWhere: Sloan Auditorium (Goergen 101)

Posted in Announcements, Summer Student Colloquium Series | Leave a comment

7/15 Summer Colloquium Speaker Announcement

OLYMPUS DIGITAL CAMERAOn Tuesday, July 15th the UR SPIE student chapter will be continuing its Summer Colloquium series. Please bring your lunch and come listen to our next presentation! Snacks and beverages will be provided.

Who: Robin Sharma
What: Two-photon fluorescence imaging of the retina in the living eye using adaptive optics
Date: 7/15/2014
Time: 11:30 am – 12:30 pm
Where: Sloan Auditorium (Goergen 101)
Abstract: Adaptive optics scanning laser ophthalmoscopy (AOSLO) permits diffraction-limited imaging of microscopic structures in the retina in living eyes. Thanks to various advances in system design and image registration software, functional imaging of different cell classes in the retina is within reach. Two-photon fluorescence imaging has a number of advantages for retinal imaging. All cells in the retina fluoresce with appropriate infrared two-photon excitation, offering the possibility of imaging every class of retinal cell, even those that are transparent in visible light. It also allows the study of molecular species whose excitation regime is in the ultraviolet, a region of the spectrum that is inaccessible in reflectance and single photon fluorescence imaging because it lies outside the transmittance spectrum of the ocular media. Additionally, it allows functional as well as structural imaging by monitoring molecular changes that are invisible with conventional imaging methods.
A two-photon adaptive optics scanning light ophthalmoscope has been developed for imaging living, anaesthetized primates. An ultrashort pulsed laser (~ 55 fs pulse-width) with a tunable central wavelength was used to excite two-photon fluorescence. Consistent with measurements made in excised retina, fluorescence emission was detected throughout the retina in vivo although the strongest autofluorescence signal originated from near the photoreceptor layer. Two-photon images of individual cells and other recognizable structures were obtained in multiple retinal layers such as the nerve fiber layer, individual rods as well as cones and retinal pigment epithelial cells. Also, the time-course of fluorescence from individual photoreceptor cells provides clues about the molecules that might be responsible for this autofluorescence. This is an important step towards noninvasively monitoring functional activity in individual retinal layers.
Posted in Announcements, Summer Student Colloquium Series | Leave a comment

7/8 Summer Colloquium Speaker Announcement

head_stephenOn Tuesday, July 8st the UR SPIE student chapter will be continuing its Summer Colloquium series. Please bring your lunch and come listen to our next presentation! Snacks and beverages will be provided.

Who: Steve Head
What: Arbitrary Spatially-Varying Polarization State Generator for Deep Sub-Wavelength Metrology​
Date: 7/8/2014
Time: 11:30 am – 12:30 pm
Where: Sloan Auditorium (Goergen 101)
Abstract: The lithography industry makes use of a wide array of tools for metrology of their nano-scale structures.  Scatterometry is one such method in which the scattered light from a periodic test structure is compared with theoretical results from Rigorous Coupled Wave Analysis in order to back-out structure parameters such as critical dimension, film thicknesses, and sidewall angle.  Current scatterometry methods could possibly be improved by using a focused beam to acquire angular scatter information in a single measurement and by tailoring the input polarization to make the output more sensitive to small deviations.  This talk will focus on the polarization generator I helped build and how it can be used to maximize the ability of a scatterometry system to back-out structure parameters.
Posted in Announcements, Summer Student Colloquium Series | Leave a comment

7/1 Summer Colloquium Speaker Announcement

picOn Tuesday, July 1st the UR SPIE student chapter will be continuing its Summer Colloquium series. Please bring your lunch and come listen to our next presentation! Snacks and beverages will be provided.
Who: Patrice Tankam
What: Multiple-Wavelength Digital Holography and Applications
Date: 7/1/2014
Time: 11:30 am – 12:30 pm
Where: Sloan Auditorium (Goergen 101)
Abstract: Since its discovery in 1947 by Denis Gabor, Holography was shown to be a powerful tool to perform “real” 3D imaging and optical metrology. The development of high-resolution CCDs and powerful processors during the last decades opened new opportunities to apply digital holography in different domains. Digital holography combines the interferometric recording of the light scattered from the object and the back-propagation computation of the interference pattern to retrieve the 3D information of the object. Most of the recent developments and accomplishments in digital holography were based on a single-wavelength configuration. However, a multiple-wavelength is necessary to obtain the true color of the object or the absolute value of the measurement. This presentation will focus on my contribution in multiple-wavelength digital holography applied in several projects (aerodynamic flow visualization, mechanics, electronics, etc).

 

Posted in Announcements, Summer Student Colloquium Series | Leave a comment

6/24 Summer Colloquium Speaker Announcement

33417_10150198994745459_552840_n

On Tuesday June 24th, the UR SPIE student chapter will be kicking off its annual Summer Colloquium series. Because this is the kickoff of the colloquium series, we will be providing FREE PIZZA in addition to other snacks and refreshments!
Who: Dustin Shipp
What: Precise, time-lapsed measurements of organelle sizes in single cells by Holographic Angular Domain Elastic Scattering (HADES)
Date: 6/24/2014
Time: 11:30 am – 12:30 pm
Where: Sloan Auditorium (Goergen 101)
Abstract: We demonstrate a label-free method of simultaneously measuring chemical and structural changes in a single cell over time. Raman spectroscopy obtains chemical information. Angular scattering allows estimates of organelle sizes. Previously, organelle size estimates in single cells were unstable due to the effects of speckle. The small illuminated field causes speckle to affect measurements of single cells more than measurements of many cells or bulk tissue. These speckle effects have been overcome through holographic angular domain elastic scattering (HADES), which records a complex scattered field that can be numerically propagated to any plane. In the image plane, we apply a series of virtual diffusers that reduce the coherence between different intracellular scatterers. Such diffusers are most easily created in silico, necessitating manipulation of the full complex field. By reducing the coherence between scatterers, HADES is able to reduce the effects of speckle and obtain stable organelle size estimates from single cells. To demonstrate the effectiveness of HADES on a biological system, we induce mitochondrial swelling and measure the organelle sizes of single cells over the next several hours. HADES and Raman spectroscopy are both well-suited to study a variety of changes in single cells over time. Prospective cellular systems for study by these methods will be discussed.
Posted in Announcements, Summer Student Colloquium Series | Leave a comment

FARO Technologies – 9/13/13

faroOn Friday, September 13th, a representative from FARO Technologies will be present.  Please join us for a lunchtime session featuring a company presentation, product demos, and, of course, free pizza.  See below for more details.

Speaker:  Michelle C. Edwards
Title:  Optical Technology in Imaging and Portable Coordinate Metrology – Bringing the Real World to the Virtual World.
Abstract: FARO the world’s most trusted source for 3D measurement technology, develops and markets computer-aided measurement and imaging devices and software. Technology from FARO permits high-precision 3D measurement, imaging and comparison of parts and complex structures within production and quality assurance processes. The devices employ varied technologies, and are applied to compare real world parts to engineering design data in industries such as aerospace and automotive; The devices also capture the as-built state of objects and define them in the virtual world to allow for duplication, modification, or documentation of the data needed in industries. This session will present the technology, and allow opportunity for hands on experience with a laser tracker, laser scanner, and Scan arm.

Venue: Goergen 108
Date: 9/13/13
Time: Noon – 2 pm

Speaker Bio: Michelle Edwards is the Applications Engineering Manager for the Americas Region, at FARO Technologies Inc, the leading provider of 3D laser measurement tools.  Michelle has worked for FARO Technologies since 2003. She leads a team of 28 engineers, who are in the field supporting the firm’s clients, account managers and distributors in the sales, installation and training processes.  Michelle is also accountable for the recruitment of engineers for her team.    At FARO, Michelle has been a part of projects in support of customers including GE Energy, the US Army, NASA, Lockheed-Martin, Boeing, Hyundai and hundreds of other initiatives.   The type of projects have included  development of inspection routines, customization of training programs, and adapting new technology to enable modifications and upgrades of aircraft & vehicles onsite instead of transporting them.

Prior to joining FARO, Michelle was a business owner in the hospitality industry operating a franchised hotel and restaurant.  In her business, she led the initiative to ensure guests, corporations, and neighboring businesses all communicated to achieve the highest level of satisfaction for customers.

Michelle received a BS in Aerospace Engineering from the Embry Riddle Aeronautical University.  She lives with her husband and two children in Ormond Beach, FL.

Posted in Announcements | Leave a comment

8/15 UR SPIE Summer Colloquium Series

On Thursday, August 15th, the UR SPIE student chapter will be concluding its annual Summer Colloquium series with a special doubleheader.

7767Speaker #1: Janghwan Bae
What:  Vacuoles: Visual Performance in Intraocular Lenses

Abstract:  In certain formulations of intraocular lenses, localized concentrations of water can accumulate over time with variable environment conditions. Since the index of refraction of water is significantly lower than that of the base polymer, the optical effects of these vacuoles can become visually significant. To assess the effect of vacuoles, the scattering behavior would be analyzed. And LightTools calculation is included. Experimentally, this effect can be seen with our scatterometer. As conclusion, the resolution of eye is not affected by vacuoles. But, there is the loss of light come up to retina. This can affect the visual contrast of human.

Briggs_PhotoSpeaker #2: Dennis Briggs
What:  Accurately Measuring the Dynamic Coefficient of Friction in UltraForm Finishing

Abstract: UltraForm Finishing (UFF) is a deterministic subaperture computer numerically controlled grinding and polishing platform designed by OptiPro Systems. UFF is used to grind and polish a variety of optics from simple spherical to fully freeform, and numerous materials from glasses to optical ceramics. The UFF system consists of an abrasive belt around a compliant wheel that rotates and contacts the part to remove material. This work aims to accurately measure the dynamic coefficient of friction (m), how it changes as a function of belt wear, and how this ultimately affects material removal rates. The coefficient of friction has been examined in terms of contact mechanics and Preston’s equation to determine accurate material removal rates. By accurately predicting changes in m, polishing iterations can be more accurately predicted, reducing the total number of iterations required to meet specifications. We have established an experimental apparatus that can accurately measure m by measuring triaxial forces under translating loading conditions. Using this system, we will demonstrate m measurements for UFF belts during different states of their lifecycle and assess the material removal function from spot diagrams as a function of wear. Ultimately, we will use this system for qualifying belt-wheel-material combinations to develop a spot-morphing model to better predict instantaneous material removal functions.

Date: 08/15/2013
Time: 11:30 am – 12:30 pm
Where: Sloan Auditorium (Goergen 101)

**Important** Pizza will be provided in addition to snacks and beverages.

Posted in Announcements, Summer Student Colloquium Series | Leave a comment

8/08 UR SPIE Summer Colloquium Series

Visconti_AnthonyOn Thursday, August 8th, the UR SPIE student chapter will be continuing its annual Summer Colloquium series.

Who: Anthony Visconti

What: Design and Fabrication of Large Diameter Radial Gradient-Index Lenses for Dual-Band Visible to Short-Wave Infrared Imaging Applications

Date: 08/08/2013

Time: 11:30 am – 12:30 pm

Where: Sloan Auditorium (Goergen 101)

Abstract: The lack of fabrication methods to produce large diameter (>20 mm) radial gradients has historically restricted their use in commercial optical systems. Ion exchange is a well-known process used in the chemical strengthening of glass and the fabrication of waveguide devices and small diameter (<4 mm) gradient-index (GRIN) optical relay systems. The technique is relatively straightforward to implement and therefore attractive for GRIN fabrication; however, the manufacturing of large-diameter radial gradients with ion exchange is limited by long diffusion times.

Materials research presented in this work aims to characterize the manufacturing process of a fast-diffusing titania silicate glass in both Li+ for Na+ and Na+ for Li+ ion exchanges. Manufacturing challenges associated with diffusion in titania silicate glass are addressed in order to extend its manufacturability to large diameter (15 – 20 mm) radial diffusions.

Additionally, a polychromatic GRIN design model is utilized to illustrate the potential usefulness of GRIN elements in dual-band visible to shortwave infrared (vis-SWIR) imaging applications. Color correction in the vis-SWIR using standard optical materials proves quite difficult especially over large temperature ranges. The benefits of radial GRIN elements in color correction of broadband vis-SWIR imaging applications stems from the unique dispersion properties of the material.

Bring your lunch!  Snacks and beverages will be provided.

Posted in Uncategorized | Leave a comment

8/01 UR SPIE Summer Colloquium Series

imageWho: Dan Christensen

What: Application of Random Access Multiphoton (RAMP) Microscopy to Capillary-level Cerebral Blood Flow Imaging in Mice In Vivo

Date: 08/01/2013

Time: 11:30 am – 12:30 pm

Where: Sloan Auditorium (Goergen 101)

Abstract: It’s a bird, it’s a plane, no…it’s a mouse with half of its skull removed strapped to a translation stage! Come hear about how we’re measuring capillary-level blood flow in the brain and the microscope we developed to do it. It’s a familiar tale of joy intermixed with heartache, triumph laced with struggle, and long days accompanied by short nights. This gripping presentation will introduce you to the messy world of live-animal imaging and the optics and electronics we use to do it. Specifically, we have constructed a laser-scanning two-photon microscope employing acousto-optical deflectors (AODs) rather than traditional mirror galvanometers. This gives our microscope a temporal advantage over commercially available systems, allowing us to track individual red blood cells throughout multiple capillaries inside the brain simultaneously.

Bring your lunch!  Snacks and beverages will be provided.

Posted in Announcements, Summer Student Colloquium Series | Leave a comment

7/25 UR SPIE Summer Colloquium Series

33417_10150198994745459_552840_nOn Thursday, July 25th, the UR SPIE student chapter will be continuing its annual Summer Colloquium series.

Who: Dustin Shipp

What: Overcoming speckle in angular scattering measurements of single cells

Date: 07/25/2013

Time: 11:30 am – 12:30 pm
Where: Sloan Auditorium (Goergen 101)

Abstract: Angular scattering is used study sub-cellular structure including organelle sizes. However, organelle size estimates in single cells are often unstable due to speckle. Angular-domain scattering interferometry (ADSI) overcomes these speckle effects. ADSI recovers the full complex scattered field, which allows the application of virtual diffusers to reduce the intracellular coherence between different scatterers while leaving the signatures of individual scatterers relatively intact. By reducing the coherence between scatterers, ADSI reduces the effects of speckle and obtains stable organelle size estimates from single cells.

Bring your lunch!  Snacks and beverages will be provided.

Posted in Announcements, Summer Student Colloquium Series | Leave a comment