Friday, May 13th, 1:00 pm (PST) -- pizza provided!
Hosted in-person in ESB 1001 and via Zoom
Bio – Alexa Hudnut is an Optical Systems Engineer at Illumina in San Diego. Her research background is true to a Biomedical Engineer – a little bit of everything. She started her research in molecular biology and gene editing and then worked her way to instrumentation design and optics. She graduated with a PhD in Biomedical Engineering from the University of Southern California in 2018. She is most passionate about creating medical devices that leverage Optics and Materials Science for an intentionally sustainable future.
Abstract – Illumina’s mission is to improve human health by unlocking the power of the genome. This translates to efforts such as tracking COVID variants, determining your dog’s breed, population genomics, and everything in between. Next generation sequencing (NGS) relies heavily on epifluorescence microscopy as the backbone of instrumentation. As we look toward the future of gene sequencing, it will become more prevalent as an in vitro diagnostic (IVD). To improve the clinical workflow, increased throughput is necessary for quicker turnaround times. These improvements are being driven by innovations such as structured illumination, multiplexing, image processing, and nanofabrication.
As part of the SBMA Free Community Day on April 7, 2022, the Photonics Society hosted a color mixing activity on the terrace in front of the art museum. Guests learned about additive and subtractive color mixing while having fun mixing paints. Several guests proved to be talented young artists, making beautiful recreations of Van Gogh paintings by mixing cyan, magenta, and yellow paint to create a variety of colors.
Friday March 4th at 1:00pm PST in Henley Hall 1010 and via Zoom
Pizza Provided in-person!
Porous semiconducting nitrides are effectively a new class of semiconducting material, with properties distinct from the monolithic nitride layers from which devices from light emitting diodes (LEDs) to high electron mobility transistors are increasingly made. The introduction of porosity provides new opportunities to engineer a range of properties including refractive index, thermal and electrical conductivity, stiffness and piezoelectricity. Quantum structures may be created within porous architectures and novel composites may be created via the infiltration of other materials into porous nitride frameworks. A key example of the application of porous nitrides in photonics is the fabrication of high reflectivity distributed Bragg reflectors (DBRs) from alternating layers of porous and non-porous GaN. These reflectors are fabricated from epitaxial structures consisting of alternating doped and undoped layers, in which only the conductive, doped layers are electrochemically etched. Conventionally, trenches are formed using a dry-etching process, penetrating through the multilayer, and the electrochemical etch then proceeds laterally from the trench sidewalls. The need for these trenches then limits the device designs and manufacturing processes within which the resulting reflectors can be used. We have developed a novel alternative etching process, which removes the requirement for the dry-etched trenches, with etching proceeding vertically from the top surface through channels formed at naturally-occurring defects in the crystal structure of GaN. This etch process leaves an undoped top surface layer almost unaltered and suitable for further epitaxy. This new defect-based etching process provides great flexibility for the creation of a variety of sub-surface porous architectures on top of which a range of devices may be grown. Whilst DBR structures enable improved light extraction from LEDs and the formation of resonant cavities for lasers and single photon sources, recent development also suggest that thick, subs-surface porous layers may enable strain relaxation to help improve the efficiency of red microLEDs for augmented reality displays. Meanwhile, the option of filling pores in nitride layers with other materials provides new opportunities for the integration of nitrides with emerging photonic materials, such as the hybrid-perovskite semiconductors, with perovskites encapsulated in porous nitride layers demonstrating greatly improved robustness against environmental degradation.
Thursday, November 18th, 11 am (PST) in Henley Hall 1010
Pizza will be provided!
Cutting edge diode lasers and PICs for sensing applications
Over the past several years, many new application areas for photonics in optical sensing have opened up. In this talk, we will review record performance diode laser and PIC technology developed by Freedom Photonics for a variety of optical sensing applications - gas sensing, atomic sensing and LIDAR.
Basic skills for a good technical team leader
Many engineers with advanced degrees end up leading high-impact technical teams, in pursuit of research, development or production. In this talk, we will discuss various practical issues related to being a good team leader.
Join us at Henley Hall 1010 on 10/28 at 1pm! Free Pizza Provided!
Thursday, July 15, 10:00 - 11:00 am (PDT)
5 years after the earth-based gravitational wave observatory, LIGO, made its first detection of gravitational waves, work is already well underway in preparing for the next generation of gravitational wave observatories – in orbit around the sun. Working with NASA Goddard Space Flight Center, we are building what will be the “quietest” oscillator in (and above) the world to serve as the core light source for the interferometric system. The system is based on a non-planar ring oscillator (NPRO) model, which I will discuss along with some of the challenges that arise when developing laser systems for space applications.
Friday May 28 at 1:00 pm
The UCSB Quantum Foundry and the UCSB Photonics Society hosted the 2021 Quantum Industry Showcase on April 22 and 23. You can watch the Keynote address and the fireside chat below. You can also find more information and presentations from the event at https://qis.quantumfoundry.ucsb.edu/.
Like these videos? Watch the full QIS 2021 playlist at
1:00 PM Friday, April 2nd
Breaking the Bounds of Imaging in Label-Free Nanoscopy, Micro-Endoscopy and Ophthalmology - Dr. Zalevsky
Thursday, February 25th, 10 am (PST) via Zoom
Meeting ID: 854 2977 2482 Passcode: 230903
Both human vision and imaging systems have limited capability to separate spatial features, and this information can only be extracted from a limited range in depth. These limitations arise from diffraction, i.e., the finite dimensions of the imaging optics and the geometry of the sensor. In this talk, I will present novel photonic approaches to exceed the resolution limitations of geometric optics. I will show how those concepts can be adapted to micro endoscopy as well as to microscopy-related configurations, including ophthalmic devices for correcting visual deficiencies.
Friday, January 29th, 10 am (PST)
Infrared detectors and imaging systems are becoming increasingly important in a diverse range of astronomic, military, and civilian applications. This field has gained significant attention while incorporating various materials and architectures into detector designs with a strong focus on applicability into clinical domains. Dr. Perera will discuss recent detector structures, and his latest work on disease detection. Biomedical applications of infrared include an exploration of an Affordable, Sensitive, Specific, User-friendly, Rapid, Equipment-free, and Deliverable (ASSURED) diagnostic regimen and testing its clinical feasibility for inflammatory bowel diseases (IBDs) and cancer screening. A study using Fourier transform infrared (FTIR) spectroscopy in attenuated total reflectance (ATR) sampling mode analyzed body fluids in order to identify reproducible, stable, and statistically significant differences in spectral signatures of the IR absorbance spectra between the control and disease samples. These results show that serum samples can be used to detect the biochemical changes induced by these diseases.
1:00 PM Friday, January 22nd
Strong THz laser fields can explore non-linear, non-equilibrium phenomena in matter. The talk will focus on photons emitted by electron/hole re-collisions, and how the polarization of these photons carries information about the semiconductor.
Following the technical talk, I will give a short professional development talk, including networking and volunteering in the photonics community, and I will cover some career advice for graduate students.