The integrated photonics and fiber optics industries are rapidly expanding and innovating, respectively, to enable transformative new integrated circuit, AI, datacom, wireless, sensing and imaging systems for cloud and mobile computing, automobile and aircraft, display, medical, and energy industries. This 21st century advanced manufacturing sector is in dire need of a massive increase in its photonics engineer and technician workforce, over the next decade. To support this near-term workforce demand, a modular library of digital simulations (sims) and blended (digital and hands-on) learning content are needed to supplement current university or community college curricula, professional training workshops, and also nourish a K-12 pipeline of future industry talents. A multi-university education research team led by MIT, Clemson University, and The University of Arizona, has completed an integrated photonics and fiber optics industry education roadmap, and created a mix of (i) desktop Virtual Reality (VR) tool-training sims, (ii) photonics device visualization sims, and (iii) application-focused educational games, for both online MOOC learning and blended learning in training bootcamps. In addition, (iv) an Augmented Reality Game (ARG) has been created for K-12 engagement. Collectively, these education assets can facilitate the upskill of photonics-adjacent industry incumbent and incipient workers; the reskill of legacy photonics industry incumbent workers; and acculturate a next-generation workforce to evolving photonics careers. We review examples of (i)-(iii), including an optical fiber preform lathe and fiber draw tower sim; a photonic chip die bondersim; passive and active microphotonic device sims; and games that instruct in the operational trade-offs of photonics-enabled hyperscale data centers, on-chip chemical gas sensors, mmWave wireless drones, and LiDAR imaging vehicles. Such a cumulative curricular instruction is anticipated to fortify learner motivation by interconnecting the procedural skilling of manufacturing tools, with the scaffolding of photonics device function intuition, and constraint-analysis of complex real-world engineering systems. Results from summative A/B testing in a MOOC course and formative assessment interviews during a blended learning bootcamp demonstrate the capacity of these interactive digital tools to both enhance (technician and engineer-level) learner retention, and reduce the preparatory overhead and cognitive load of on-site instructors. Early results from the testing of the ARG may indicate an engagement impact in K-12 introduction to integrated photonics, by highlighting causal links between the operation of complex photonics engineering systems and fundamental optics concepts, such as total internal reflection and light scattering. Collectively, these educational strategies suggest disruptive new methods to enhance interstitial learning experiences and sustain life-long learning practices for engineers and technicians pursuing microelectronics and integrated photonics careers.

A glucose sensor based on a helical long-period grating (HLPG) coupling to a high-order cladding mode is demonstrated, which is composed of an optical fiber with the fiber surface modified by poly (4-vinylphenylboronic acid). The sensor has a linear response to glucose (0.18 similar to 3 mg/mL) with a sensitivity of 1.115 nm.(mg/mL)(-1) at pH 7.4 and 3.259 nm.(mg/mL)(-1) at pH 9, respectively.

An optical fiber interferometer coated with PbS quantum dots (QDs) was developed for copper ion (${{\rm{Cu}}^{2 +}}$) detection. The QDs were modified by a multifunctional copolymer that enabled QD surface ligation, dispersion, and coordination with ${{\rm{Cu}}^{2 +}}$. ${{\rm{Cu}}^{2 +}}$ coordination with the polymer induced changes in the surrounding refractive index of the interferometer. The sensor was highly selective for ${{\rm{Cu}}^{2 +}}$ and showed a linear detection range of 0-1000 µM with a limit of detection of 2.20 µM in both aqueous and biological solutions.

Silicon-based photonics is mobilizing into a manufacturing industry with specialized integrated circuit design requirements for applications in low power cloud computing, high speed wireless, smart sensing, and augmented imaging. The AIM Photonics Manufacturing USA Institute, which operates the world's most advanced 300mm semiconductor research fab, has co-developed a Process Design Kit (PDK) in fabless circuit design for these expanding digital and analog applications; however, there currently isn't available an in-depth curriculum to train engineers (academia, industry) in the AIM PDK process and Electronic Photonic Design Automation (EPDA) software. AIM Photonics Academy, an education initiative of AIM Photonics based at MIT, has collaborated with faculty to create three online MOOC edX courses that (1) introduce integrated photonics devices, and applications performance needs and metrics; and (2) train into the AIM PDK and specialized EPDA tools in a six week design project to lay out an application-specific photonic transceiver. The courses are structured around asynchronous video lectures and exploratory design problems that involve Python and Matlab-based first-principles calculations (systems modeling) or advanced EPDA tools (circuit design and layout). The online MOOC courses can optionally form a tandem blended learning component with two AIM Photonics Academy on-site training programs: the annual AIM Summer Academy one-week intensive program (held every July at MIT), or a photonic integrated circuit testing workshop (the first workshop is planned for fall 2019). These courses are a cornerstone effort at AIM to found and support a specialized cohort community of future integrated photonics designers.

A non-enzymatic, sensitive glucose sensor was fabricated based on an evanescent wave absorbing optical fiber probe. The optical fiber sensor was functionalized by fixing a poly (phenylboronic acid) (polyPBA) film onto the conical region of the single mode fiber. The reflected light intensity of the polyPBA-functionalized fiber sensor increased proportionally with glucose concentration in the range of 0–60 mM, and the sensor showed good reproducibility and stability. The developed sensor possessed a high sensitivity of 0.1787%/mM and good linearity. The measurement of glucose concentration in human serum was also demonstrated.

We have demonstrated a passively mode-locked erbium-doped fiber laser using colloidal PbS quantum dots (QDs) thin film as saturable absorbers (SAs). As the pump power up to 34.1 mW, we can observe the mode-locked pulse with the duration of 2.86 ns.

A PbS quantum dot optical fiber amplifier with enhanced processability and environmental stability is described. Modification of PbS quantum dots with multifunction copolymers was demonstrated via spectroscopy to aid dispersion of the quantum dots in a sol during the fabrication of a quantum dot optical fiber amplifier without degradation or modification of optical properties. The influence of multifunction copolymers and oleylamine-coated PbS quantum dots on the structure was studied via scanning electron microscopy. The nanoparticle shape of oleylamine-coated PbS quantum dots after polymer modification remained unchanged compared to those previously reported. With the addition of a fluorine-containing component, a PbS quantum dot optical fiber amplifier retained 96% of its initial gain after 100 days, as compared with 16% for quantum dots modified with a non-fluorine-containing polymer, it was certain that fluorine bond of multifunction copolymers had a good improvement in durability of PbS quantum dot. Simultaneously, PbS quantum dot optical amplifier gain as high as 17 dB was achieved at 1550 nm.

This project involves the construction of a remote-controlled laboratory experiment that can be accessed by online students. The project addresses a need to provide a laboratory experience for students who are taking online courses to be able to provide an in-class experience. The chosen task for the remote user is an optical engineering experiment, specifically aligning a spatial filter. We instrument the physical laboratory set up in Tucson, AZ at the University of Arizona. The hardware in the spatial filter experiment is augmented by motors and cameras to allow the user to remotely control the hardware. The user interacts with a software on their computer, which communicates with a server via Internet connection to the host computer in the Optics Laboratory at the University of Arizona. Our final overall system is comprised of several subsystems. These are the optical experiment set-up, which is a spatial filter experiment; the mechanical subsystem, which interfaces the motors with the micrometers to move the optical hardware; the electrical subsystem, which allows for the electrical communications from the remote computer to the host computer to the hardware; and finally the software subsystem, which is the means by which messages are communicated throughout the system. The goal of the project is to convey as much of an in-lab experience as possible by allowing the user to directly manipulate hardware and receive visual feedback in real-time. Thus, the remote user is able to learn important concepts from this particular experiment and is able to connect theory to the physical world by actually seeing the outcome of a procedure. The latter is a learning experience that is often lost with distance learning and is one that this project hopes to provide.

The fluorescence intensity drop rate of PbS quantum dot with fluorine-containing polymer is 9.76% and the gain drop rate of quantum dot fiber amplifier (QDFA) with fluorine-containing polymer is 57.66% separately with temperature, which is more stable than no fluorine polymer QDFA.

With the goal to extend applications of highly photosensitive photo-thermo-refractive (PTR) glass from bulk glass components to the fiber optic platform, we have successfully fabricated single material fibers and step index fibers from PTR type glasses. The fibers were drawn from rod-in-tube preforms which have been prepared using specialty diamond tools for shaping and polishing of the glass materials. We measured attenuations of less than 0.1 dB/cm in our PTR glass fibers. Strong fiber Bragg gratings were inscribed into the novel fibers demonstrating the fibers photosensitivity. High grating strength of up to 20 dB were reached and maintained even at 12 hour exposure to temperatures above 400 degrees C. Our results open exciting new avenues for the development of holographic PTR glass fiber optic components which may be applied in fiber optic devices that require high temperature stability and high optical power levels.

New synthesis techniques for highly concentrated colloidal C60 suspensions were developed. The nonlinear absorption and nonlinear scattering behavior of colloidal C60 suspensions and benchmark materials (carbon black suspension and C60 solution) were studied with an apparatus that simultaneously measured the total scattered and transmitted energy, inferring absorbance. These experimental results were compared to simple thermodynamic and reverse saturable absorption models, as well as a hybridized model proposed for the nonlinear optical behavior of C60 colloids. All samples followed an attenuation pattern in the nonlinear scattering regime that was fit by a single extinction coefficient, indicating that the energy in excess of that required to reach the sublimation threshold does not significantly affect the size of the induced scattering centers. C60 colloids evidenced strong quenching of the first excited singlet band, leading to weak intersystem-crossing to the triplet manifold. The degree of quenching was morphology dependent. Tighter crystalline packing led to stronger quenching. Samples with higher triplet quantum yield evidenced less efficient heating of the particles. Consequently, for otherwise similar C60 colloids, stronger nonlinear absorption response was found to diminish the nonlinear scattering response. Large, crystalline C60 colloids had a stronger nonlinear optical response than benchmarks.

Poor thermal stability has remained a severe obstacle for practical applications of optical fiber amplifiers based on quantum dots (QDs). We demonstrate that thermal stability at elevated temperatures can be achieved by using oleic-acid-capped QDs. Optical fiber amplifiers using oleic-acid-capped QDs for the gain medium exhibited stable gain of more than 5 dB at 1550 nm between 25 °C and 50 °C that did not degrade upon cooling. In contrast, fiber amplifiers employing oleylamine-capped QDs exhibited reduced gain when heated and subsequently cooled.

The use of optical fibers to couple spectrographs to telescopes has been important in the search for extrasolar planets using radial velocity measurements. The ability of an optical fiber to partially scramble the input illumination enables a fiber feed to provide more uniform illumination to the spectrograph optics, but a limiting factor in fiber coupling is modal noise. Agitation of the fiber has been shown to reduce modal noise, but altering fiber transmission parameters by varying the length of the fiber may offer advantages. We report on tests comparing some of the alternative devices for reducing modal noise.

Optical fiber amplifiers based on PbS/CdS semiconductor quantum dots (QDs) modified by an amphiphilic polymer were demonstrated. Well-defined QDs and an amphiphilic copolymer were first prepared and the amphiphilic copolymer was then used to disperse the QDs into silica sol to allow uniform and reproducible incorporation of QDs into the silica coating of the optical fibers. QD-doped silica sol was deposited on the fusion tapered fiber coupler via dip-coating. A 1550 nm semiconductor light emitting diode as the signal source and a 980 nm laser diode as the pump source were injected into the fiber coupler simultaneously. Through evanescent wave excitation, a signal gain as high as 8 dB was obtained within the wavelength range between 1450 and 1650 nm. In addition, the optical fiber amplifiers based on PbS/CdS QDs showed enhanced thermal stability when compared to amplifiers based on PbS QDs.

Solar concentrators are frequently characterized by an acceptance angle that specifies optical throughput when the concentrator is misaligned. Here we introduce an effective acceptance angle that includes the effect of illumination non-uniformity on system performance.

This paper describes optically tandem solar cells with improved spectral efficiency for the blue, UV, and near infrared portions of the solar spectrum. Optically tandem cells are constructed by stacking frequency converting materials and photovoltaic devices so that they are optically coupled.

We examine the photophysics of a colloidal suspension of C(60) particles in a micellar solution of Triton X-100 and water, prepared via a new synthesis which allows high-concentration suspensions. The particle sizes are characterized by transmission electron microscopy and dynamic light scattering and found to be somewhat polydisperse in the range of 10-100 nm. The suspension is characterized optically by UV-vis spectroscopy, femtosecond transient absorption spectroscopy, laser flash photolysis, and z-scan. The ground-state absorbance spectrum shows a broad absorbance feature centered near 450 nm which is indicative of colloidal C(60). The transient absorption dynamics, presented for the first time with femtosecond resolution, are very similar to that of thin films of C(60) and indicate a strong quenching of the singlet excited state on short time scales and evidence of little intersystem crossing to a triplet excited state. Laser flash photolysis reveals that a triplet excited-state absorption spectrum, which is essentially identical in shape to that of molecular C(60) solutions, does indeed arise, but with much lower magnitude and somewhat shorter lifetime. Z-scan analysis confirms that the optical response of this material is dominated by nonlinear scattering.

We have developed a permanent fiber optic cable splice for avionics applications that provides the capability of cable restoration for field/fleet-environment on-aircraft repair of broken fiber optic cables. Prototype samples have passed stringent environmental research testing requirements specified by NAVAIR whereby the pass-fail criterion was set at 1 dB maximum insertion loss.