Location:	Rebecca's Cafe, 275 Grove St., Auburndale, MA 02466
	Dinner Reservation Deadline:	May 15, 2017 @ 6pm

Computational Imaging Through Scattering

Imaging through scattering media has long been a challenge, as scattering corrupts measurements in a non-invertible way. Using near-visible wavelengths to image through scattering media can realize broad applications in bio-medical and industrial imaging. It provides many advantages, such as optical contrast, non-ionizing radiation and availability of fluorescent tags. In this talk I'll discuss recent techniques that were developed to overcome and use scattering in order to recover scene parameters. Our computational imaging approach is based on an ultrafast time-resolved measurement of light transport. The measurement provides high-dimensional data that is used in an algorithmic framework to computationally invert the scattering. I'll demonstrate this approach in two different scenarios: first, a method to recover the location of fluorescent markers hidden behind turbid layer and classify them based on florescence lifetime analysis; second, a method to recover a scene hidden behind a thick tissue phantom. The talk is self-contained and no prior knowledge is required.

	Location:	Rebecca's Cafe, 275 Grove St., Auburndale, MA 02466
	Dinner Reservation Deadline:	Monday February 13 @ 6pm

NES/OSA Promoting STEM with Optics 

In addition to professional development, educational outreach is one of the key initiatives of the NES/OSA. We have been active in the promotion of STEM (Science, Technology, Engineering and Math) since the mid-1970s with the goal of fostering excitement about science and bringing awareness of optics to children. Some of the programs in which we have been engaged include bringing optics into classrooms (with the famous optics suitcase), student scholarships, teacher grants, and volunteering in community science events.

NES/OSA currently participates in several community programs from STEM Expos to Science Fairs with combined audiences of several thousand students annually, awarded the OSA Excellence Award for outreach last year. Especially in recent years, we have increased our commitment with participation in a growing number of events. This could not have been accomplished without the committed NES/OSA members who have generously volunteered their time and knowledge at these events. As they will tell you, introducing optics to young minds is very rewarding.

Our meeting this month will divert somewhat from the normal format, as we would like to invite our members and the general public to learn more about our outreach efforts and experience some of the tools that we use to explore optics in everyday life. There will be a short presentation on STEM efforts in the community and a call for individuals to join the effort. Many of the demonstrations that we use at STEM events will also be on display. Members familiar with the demo materials will be available to describe how they are used explain fundamental optics ideas to children at various ages. We also encourage attendees to share ideas with us!

This will also be a great opportunity to bring family members interested in increasing their optics knowledge (and who may be curious about these NES/OSA meetings we keep sneaking off to on Thursday nights) .

	Location:	Rebecca's Cafe, 275 Grove St., Auburndale, MA 02466
	Dinner Reservation Deadline:	March 13, 2017 @ 6pm

Mid-infrared photothermal imaging in the fingerprint region

Mid-infrared spectral imaging in the fingerprint region (at wavelengths ~5µm and longer) can reveal characteristic details about molecular compounds and secondary structure of chemicals and biomolecules. In this talk, the development of a contact-less, non-destructive mid-infrared imaging system with high sensitivity and specificity based on photothermal spectroscopy will be presented. First, the development of low-noise, near-infrared fiber lasers will be discussed. Next, the photothermal system that integrates a compact fiber laser with a tunable mid-infrared quantum cascade laser as a robust table-top measurement system will be introduced. The imaging contrast relies on absorption of the mid-infrared pump laser from vibrational normal modes which induces thermal changes in the refractive index that are measured with the probe laser. With scaling of the pump power a nonlinear photothermal spectroscopy regime promises a novel multi-dimensional characterization method for materials with enhanced sensitivity with improved spatial resolution. Applications of the presented system can range from chemical trace to hazardous material detection, and from identification of neurodegenerative diseases based on secondary protein configurations, to remote sensing and process control.

	Location:	MIT Lincoln Laboratory, 3 Forbes Road, Lexington, MA 02420
	Dinner Reservation Deadline:	January 16, 2017 @ 6pm

Photons over electrons: Optical Fiber Sensors For Measuring Small Signals In Harsh Environments

Joint Meeting with Boston Chapter, IEEE Photonics Society

Optical fibers can be used to create high performance sensors because of several advantages that optical systems can provide over electronics.  For example, the precision of optical interferometry in measuring sub-nanometer displacements allows for measurements of very small physical changes, while immunity to electromagnetic interference and very low signal attenuation allows for high fidelity transmission of analog signals over long distances in challenging environments.  MagiQ Technologies develops different types of optical sensors; in this talk, I will focus on a highly rugged, remotely interrogated seismic sensor.  Such a device can provide accurate knowledge of geophysical processes in harsh environments where electronic sensors quickly fail or require frequent maintenance, such as oil and gas reservoirs or geothermal power systems.  In addition, large numbers of sensors can be connected via fiber optic cables in very long arrays without active elements, where a conventional electronic approach requires costly amplifiers, digitizers, and data handling hardware distributed throughout the array.  Although general operating principles and potential sensor performance are relatively well established, there are many challenges to design and produce a sensor system in a cost-effective, reliable, and scalable way.