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Fiber design strategies for increased threshold of SBS and TMI are presented. We report a high efficiency erbium nanoparticle doped fiber incorporating acoustic guiding layers with a significantly reduced SBS gain coefficient.

We have developed cladding layers for single crystal optical fiber using RF magnetron sputtering. We discuss the deposition and growth techniques, challenges, and prospects for these materials and their use as optical fiber claddings.

We investigate high-energy pulse amplification in a counter-directionally cladding-pumped partly-quenched heavily erbium-doped fiber. Despite the quenching, we reach a pulse energy of 0.38 mJ, which is several times the saturation energy at the 1563-nm signal wavelength.

An Er-nanoparticle-doped fiber laser cladding-pumped at 975 nm generates 110 W at 1605 nm with 40.6% slope efficiency and M2~7. High Er-concentration (4×1025 ions/m3) and pump brightness allows for adequate pump absorption even without Yb-codoping.

We evaluate the suitability of chalcogenide glass films, of interest because of their exceptionally high optical nonlinearities, for applications in metasurface devices and discuss results for a chalcogenide film-based optical beam converter.

We show similar laser induced damage results for silica glass with and without random antireflective surface structures under high intensity fs-laser irradiation.

We report ~140 W of power from the laser based on Er-nanoparticle-doped fiber with direct diode pumping at 1528 nm. This is believed to be the highest power ever reported from resonantly diode-pumped Er-fiber laser.

We report on progress in development of chalcogenide based fiber and waveguide active and passive devices for routing, switching, and modulation of mid-IR sources for mid-IR applications. Optical performance of the devices will be reported.

We report our progress in fabrication ceramic Praseodymium doped Calcium Lanthanum Sulfide for potential mid-IR laser gain material. Fabrication and spectroscopy of this new gain material will be reported.

We report on fabrication and optical properties of crystalline cladded single crystal Yb:YAG fiber. Net gain has been demonstrated in the cladded Yb:YAG fiber structures

We report on fabrication of crystalline cladded single crystal Yb:YAG fiber. Net gain has been demonstrated in the cladded Yb:YAG fiber structures

Co-doping of Er with RE ions in silica fibers is used to reduce Er clustering. A single mode core pumped Er-La fiber with an Er ion concentration of 1.37×1025 ions/m3 exhibited a slope efficiency of 76%.

We report on fabrication and spectroscopy of ceramic Praseodymium doped Calcium Lanthanum Sulfide for potential mid-IR laser gain material.

We demonstrate a nonlinear metasurface made of nanostructured chalcogenide glass. We combined on- and off-resonance nanostructures to realize reconfigurable structured light beam that switches between the Hermit-Gaussian and vortex shape depending on its own intensity.

We show results for sustained optical performance of random antireflective surface structures on silica windows following sand and rain erosion and salt fog exposure, as a representative field test for laser windows in harsh environments.

We review our recent work on fusion splicing of silica fiber to As2S3 chalcogenide fiber to enable a monolithic all fiber based mid-IR supercontinuum source.

We computationally investigate cascaded amplification in a three-level mid-infrared Pr3+-doped chalcogenide fiber amplifier. We show that 45% of the pump power that is injected at 2 μm can be shifted to 4.5 μm.

Nanoparticle doping was used for making erbium doped fibers. We report luminescence lifetimes greater than for solution doped fibers, and high optical-to-optical slope efficiencies, with a maximum value greater than 71%.

We will review recent results on IR fiber based sources and devices for mid-IR applications.

This paper presents new multispectral IR glasses with transmission from 0.9 to > 14 μm in wavelength and refractive index from 2.38 to 2.17. These new glasses are designed to have comparable glass softening temperatures and compatible coefficients of thermal expansion to allow bonding and co-molding of multilayer optics. With large variation in their Abbe numbers and negative to near-zero dn/dT, optics made from these new glasses can significantly reduce the size/weight or complexity of the multispectral imaging systems for weight sensitive platforms.

We computationally demonstrate that the inclusion of multiple nested elements in As2S3 anti-resonant fibers, as in the silica case, has no effect on the overall loss. We show the dominant loss mechanisms for both cases.

We will review recent results on chalcogenide solid core and clad chalcogenide fiber, microstructured fiber, as well as chalcogenide fiber based sources and devices for mid-IR applications.

We report on fabrication of rare earth doped YAG single crystal fibers cladded with both tailored glass claddings and polycrystalline YAG claddings. Net gain has been demonstrated in cladding pumped glass cladded Yb:YAG fiber structures.

The optical performance of AR surface microstructures on optics for laser systems is presented, as applied to large windows, laser crystals, lenses and optical fibers. Ultralow reflectance and very high laser induced damage thresholds have been demonstrated.

Sputtering techniques have increasingly been applied for the fabrication of Cu(In,Ga)Se2 (CIGS) thin films for photovoltaics. For some of these methods, the metals are deposited via sputtering, and selenium is supplied from a secondary source either during or after deposition. In other CIGS sputtering techniques, selenium is included directly in the sputtering targets, eliminating the need for post-deposition selenization and the reliance on toxic H2Se gas. In general, sputtering offers several advantages over other deposition methods including excellent uniformity over large areas and high material usage. Interestingly, while record efficiencies for laboratory CIGS cells have been established using co-evaporation, the recent records for CIGS modules are based on CIGS films that have been deposited via multicomponent sputtering. We discuss recent progress on sputtered CIGS, reviewing various sputter deposition methods and discussing the advantages and limitations of each. Finally, we highlight areas of research that may result in improved performance.

We review the physical and optical properties of chalcognide fibers, recent advances in chalcogenide fiber technology, sources and devices fabricated from these fibers.

The direct nano-structuring of the surfaces of an optical element is nowadays a well-established technique used primarily to enhance the light transmission through that optical element. Typically periodic or quasi-periodic in nature, these anti-reflective surface structures (ARSS) can be designed to generate strong interference effects over large bandwidths [1,2], to work in various materials [3] and to exhibit additional characteristics such as high laser damage thresholds [4]. The period of the pattern should be on a sub-wavelength scale and the height of the individual features on the wavelength scale to avoid the undesired diffraction effects (as the period becomes close to the wavelength of interest) while providing the required phase change (or optical impedance matching between the air, in the typical case, and the optical element), respectively. Modeling of these structures is typically done using rigorous coupled-wave analysis RCWA methods although the effective-index method can also provide reasonable insight (it cannot however model through the diffraction edge region) [5]. We will present a review of our work on surface nanostructuring of many technologically important optical materials and components and illustrate record-low reflectivity losses, large bandwidth and record-high laser damage thresholds.

We report on fabrication and optical properties of double clad single crystal Yb:YAG core fiber. For the first time, net gain is demonstrated in a cladding pumped Yb:YAG single crystal fiber structure.

We report new IR GRIN materials for multi-spectral IR optics with a delta-n of 0.4. These new materials transmit SWIR-LWIR (0.9 µm - >12 µm) and have dispersion gradients to enable multi-band color correction.

A nanoparticle (NP) doping technique was used for making erbium-doped fibers (EDFs). The nanoparticles were doped into the silica soot of preforms which were drawn into fibers. Results have indicated optical-to-optical slope efficiencies of 80.4%.

We report new materials for multi-spectral infrared (IR) optics including IR gradient index (IR-GRIN) materials with a delta-n of 0.1 and new homogeneous glasses. These new materials transmit SWIR-LWIR (0.9 µm - >12 µm) and fill gaps in the IR materials dispersion map.

We present a review of our work on surface nanostructuring of many technologically important optical materials and components and illustrate record-low reflectivity losses, large bandwidth and record-high laser damage thresholds.

Ruggedized cables designed for specialty IR fibers were successfully tested for laser transmission and under harsh environmental conditions. Antireflective surfaces on the fiber endfaces reduced reflections and increased IR laser damage thresholds.

Biomimetic, filter-based sensors have been designed to detect chemicals of interest. We present some of the existing approaches, and a new comparative-discrimination spectral detection approach for detection of overlapping chemical spectra.

We computationally study the irradiance enhancement in As2S3 motheye structures. We show that enhancement in the glass is minimal, matching with experiments showing an increased laser damage threshold for motheye structures versus thin-film AR coatings.

We present novel ZnO coatings for Cu(In,Ga)Se2 photovoltaics that improve device performance through their antireflective properties and their tendency to scatter incoming light at a large angle, resulting in absorption closer to the junction.

We present results for increased transmission of ~99% through end faces of high index infrared fibers with novel anti-reflective surface structures. We demonstrate increased mid-infrared laser power handling capability for fibers with AR structured surfaces.

We demonstrate a 7x1 multimode fiber combiner based on an arsenic sulfide glass multimode fiber with > 76% per port transmission. Spectral beam combining in the mid-infrared is demonstrated through the fiber combiner.

Infrared absorption spectroscopy provides very high sensitivity and specificity. Report on infrared fibers including chalcogenide photonic crystal fibers and progress on a novel Anti-Reflection Surface Structure (ARSS) technique for reducing surface reflection will be presented.

We demonstrate mid-IR Raman amplification at 4.6 µm in As2S3 fiber. ~15 dB of amplification and 24% power conversion was achieved in a 3.5 meter fiber length.

IR Chalcogenide glass fibers have broad transmission in the IR and high intrinsic nonlinearities. These nonlinear processes can be exploited to generate mid-IR sources. We report on mid-IR sources based on these fibers.

IR supercontinuum generation in chalcogenide glass fiber is reviewed. Modeling for optimizing supercontinuum generation, fiber design and fabrication, and experimental results are presented

We simulate supercontinuum generation in an As 2 S 3 chalcogenide photonic crystal fiber with a hexagonal structure, optimizing the fiber pitch and pulse duration with a 2.8 µm laser source in order to maximize the output bandwidth.

We demonstrate broadband low power supercontinuum generation in arsenic sulphide (As 2 S 3 ) tapered fiber nanowires with an effective area ∼0.8 µm2 and nonlinearity γ = 12,400 W−1 km−1. Simulations showed good agreement between theory and experiment.

We have developed infrared fibers based on chalcogenides and will demonstrate examples of the different mid-IR sources we have developed as well as highlight optical sensors using the chalcogenide fibers.

We found that 25% of the input power of a 2 µm wavelength 1 kW peak-power source can be shifted into the region between 3–5 µm using an As 2 S 3 -based chalcogenide PCF. Tapering increases the output at wavelengths above 4 µm.

We theoretically find a bandwidth of 4 µm can be generated using four-wave mixing and soliton self-frequency shift in an As 2 Se 3 -based chalcogenide PCF with an air-hole-diameter-to-pitch ratio of 0.4 and a pitch of 3 µm.