We present the design, performance, and initial activation of the Mobile Ultrafast High Energy Laser Facility, a 5 TW near-infrared laser source located on a multi-km test range at Kennedy Space Center. The system is compact, readily transportable, and provides a robust, tunable output suitable for long range studies of high intensity laser propagation. The supporting testing infrastructure, which includes stand-alone beam diagnostic stations and atmospheric monitoring capabilities, makes this facility ideal for the development of stand-offhigh energy ultrafast applications and fundamental studies of atmospheric laser science.

Observations of the collisional evolution of particle ensembles in a microgravity environment are necessary to characterize the processes that lead to the formation of planetesimals, km-size and larger bodies, within the protoplanetary disk. The two current theories of planetesimal formation, namely growth through binary sticking collisions and gravitational instability within the protoplanetary disk, have difficulties in explaining how particles grow beyond a centimeter in size. In this paper we describe the CubeSat Particle Aggregation and Collision Experiment (Q-PACE), a Low Earth Orbit 3U CubeSat mission that will provide a high-quality, long duration microgravity environment in which we will observe collisions between particles under conditions relevant to planetesimal formation. We have designed a series of experiments involving a broad range of particle size, density, surface properties, and collision velocities to observe collisional outcomes from bouncing to sticking as well as aggregate disruption in tens of thousands of collisions.

This presentation will describe the design and construction status of a new mobile high-energy femtosecond laser systems producing 500 mJ, 100 fs pulses at 10 Hz. This facility is built into a shipping container and includes a cleanroom housing the laser system, a separate section for the beam director optics with a retractable roof, and the environmental control equipment necessary to maintain stable operation. The laser system includes several innovations to improve the utility of the system for “in field” experiments. For example, this system utilizes a fiber laser oscillator and a monolithic chirped Bragg grating stretcher to improve system robustness/size and employs software to enable remote monitoring and system control. Uniquely, this facility incorporates a precision motion-controlled gimbal altitude-azimuth mount with a coudé path to enable aiming of the beam over a wide field of view. In addition to providing the ability to precisely aim at multiple targets, it is also possible to coordinate the beam with separate tracking/diagnostic sensing equipment as well as other laser systems. This mobile platform will be deployed at the Townes Institute Science and Technology Experimental Facility (TISTEF) located at the Kennedy Space Center in Florida, to utilize the 1-km secured laser propagation range and the wide array of meteorological instrumentation for atmospheric and turbulence characterization. This will provide significant new data on the propagation of high peak power ultrashort laser pulses and detailed information on the atmospheric conditions in a coastal semi-tropical environment.

In an effort to better understand the early stages of planet formation, we have developed a 1.5U payload that flew on the International Space Station (ISS) in the NanoRacks NanoLab facility between September 2014 and March 2016. This payload, named NanoRocks, ran a particle collision experiment under long-term microgravity conditions. The objectives of the experiment were (a) to observe collisions between mm-sized particles at relative velocities of < 1 cm/s and (b) to study the formation and disruption of particle clusters for different particle types and collision velocities. Four types of particles were used: mm-sized acrylic, glass, and copper beads and 0.75 mm-sized JSC-1 lunar regolith simulant grains. The particles were placed in sample cells carved out of an aluminum tray. This tray was attached to one side of the payload casing with three springs. Every 60 s, the tray was agitated, and the resulting collisions between the particles in the sample cells were recorded by the experiment camera. During the 18 months the payload stayed on ISS, we obtained 158 videos, thus recording a great number of collisions. The average particle velocities in the sample cells after each shaking event were around 1 cm/s. After shaking stopped, the inter-particle collisions damped the particle kinetic energy in less than 20 s, reducing the average particle velocity to below 1 mm/s, and eventually slowing them to below our detection threshold. As the particle velocity decreased, we observed the transition from bouncing to sticking collisions. We recorded the formation of particle clusters at the end of each experiment run. This paper describes the design and performance of the NanoRocks ISS payload.

The Planetary Atmospheres Minor Species Sensor (PAMSS) is an intracavity laser absorption spectrometer that uses a mid-infrared quantum cascade laser in an open external cavity for sensing ultra-trace gases with parts-per-billion sensitivity. PAMSS was flown on a balloon by Near Space Corporation from Madras OR to 30 km on 17 July 2014. Based on lessons learned, it was modified and was flown a second time to 32 km by World View Enterprises from Pinal AirPark AZ on 8 March 2015. Successes included continuous operation and survival of software, electronics, optics, and optical alignment during extreme conditions and a rough landing. Operation of PAMSS in the relevant environment of near space has significantly elevated its Technical Readiness Level for trace-gas sensing with potential for planetary and atmospheric science in harsh environments.

The Planetary Atmospheres Minor Species Sensor (PAMSS) is an ultra-trace gas sensor. This paper reports its transition from a Technical Readiness Level of 4 (TRL4) to TRL 5 and an established path forward to TRL6. This report describes tests of PAMSS in chambers that simulate a balloon flight to 30 km. Lessons learned inform a number of improvements, which are being implemented for a balloon flight planned for June 2014.

We have invented a novel photodetector by mating a surface plasmon resonance coupler with a graphene field effect transistor. The device enables wavelength selectivity for spectral sensing applications. Surface plasmon polaritons (SPPs) are generated in a 50 nm thick Ag film on the surface of a prism in the Kretschmann configuration positioned 500 nm from a graphene FET. Incident photons of a given wavelength excite SPPs at a specific incidence angle. These SPP fields excite a transient current whose amplitude follows the angular resonance spectrum of the SPP absorption feature. Though demonstrated first at visible wavelengths, the approach can be extended far into the infrared. We also demonstrate that the resonant current is strongly modulated by gate bias applied to the FET, providing a clear path towards large-scale spectral imagers with locally addressable pixels.

A thin-film selective absorber at visible and near infra-red wavelengths is demonstrated. The structure consists of an optically thick layer of gold, a SiO2 dielectric spacer and a partially transparent gold film on top. The optical cavity so formed traps and absorbs light at a resonance wavelength determined by the film thicknesses. Observed fundamental-resonance absorption strengths are in the range 93%–97%. The absorption red-shifts and broadens as the thickness of the top gold layer is decreased with little change in absorption strength. Thus, strong absorption with design-tunable wavelength and width is achieved easily by unstructured blanket depositions. Observed angle-dependent spectra agree well with the recent three-layer analytical model of Shu et al. [Opt. Express 21, 25307 (2013)], if effective medium approximation is used to calculate the permittivity of the top gold film when it becomes discontinuous at the lowest thicknesses.

A method to pattern infrared-absorbing gold black by conventional photolithography and lift-off is described. A photo-resist pattern is developed on a substrate by standard photolithography. Gold black is deposited over the whole by thermal evaporation in an inert gas at similar to 1 Torr. SiO2 is then deposited as a protection layer by electron beam evaporation. Lift-off proceeds by dissolving the photoresist in acetone. The resulting sub-millimeter size gold black patterns that remain on the substrate retain high infrared absorption out to similar to 5 mu m wavelength and exhibit good mechanical stability. This technique allows selective application of gold black coatings to the pixels of thermal infrared imaging array detectors. (C) 2013 Elsevier B.V. All rights reserved.

A mid-infrared intracavity laser absorption spectrometer for trace gas sensing is demonstrated. An external-cavity multi-mode quantum cascade laser with central wavelength 8.0 μm was combined with a scanning Fabry-Perot interferometer, which analyzed the change of the laser emission spectrum caused by introducing an analyte inside the cavity. The detection mechanism is based on monitoring the laser spectrum dynamics at adiabatically changing laser conditions in long pulse operation mode. Fast acquisition and vapor exchange allow nearly real-time analyte detection. Sensitivity at the level of 1 × 10−5 cm−1 was demonstrated based on a weak water vapor absorption line.

We experimentally demonstrate a structured thin film that selectively absorbs incident electromagnetic waves in discrete bands, which by design occur in any chosen range from near UV to far infrared. The structure consists of conducting islands separated from a conducting plane by a dielectric layer. By changing dimensions and materials, we have achieved broad absorption resonances centered at 0.36, 1.1, 14, and 53 microns wavelength. Angle-dependent specular reflectivity spectra are measured using UV-visible or Fourier spectrometers. The peak absorption ranges from 85 to 98%. The absorption resonances are explained using the model of an LCR resonant circuit created by coupling between dipolar plasma resonance in the surface structures and their image dipoles in the ground plane. The resonance wavelength is proportional to the dielectric permittivity and to the linear dimension of the surface structures. These absorbers have application to thermal detectors of electromagnetic radiation.

Recently Additive Manufacturing (AM) has been hailed as the “third industrial revolution” by Economist magazine [April -2012]. Precision of the product manufactured by AM largely depends on the on line process diagnostics and control. AM caters to the quest for material to suit the service performance, which is almost as old as the human civilization. An enabling technology which can build, repair or reconfigure components layer by layer or even pixel by pixel with appropriate materials to match the performance will enhance the productivity and thus reduce energy consumption. With the globalization, “Economic Space” for an organization is now spreads all across the globe. The promise of AM for Global Platform for precision additive manufacturing largely depends on the speed and accuracy of in-situ optical diagnostics and its capability to integrate with the process control. The two main groups of AM are powder bed (e.g. Laser Sintering) and pneumatically delivered powder (e.g. Direct Metal Deposition [DMD]) to fabricate components, DMD has closed loop capability, which enables better dimension and thermal cycle control. This enables one to deposit different material at different pixels with a given height directly from a CAD drawing. The feed back loop also controls the thermal cycle. New optical Sensors are either developed or being developed to control geometry using imaging, cooling rate by monitoring temperature, microstructure, temperature and composition using optical spectra. Ultimately these sensors will enable one to “Certify as you Build”. Flexibility of the process is enormous and essentially it is an enabling technology to materialize many a design. Several cases will be discussed to demonstrate the additional capabilities possible with the new sensor. Conceptually one can seat in Singapore and fabricate in Shanghai. Such systems will be a natural choice for a Global “Economic Space”. Jyoti Mazumder is Robert H. Lurie Professor of Engineering in the Department of Mechanical Engineering and Materials Science and Director of NSF Industry University Co-operative Center for Lasers and Plasmas in Advanced Manufacturing at the University of Michigan in Ann Arbor. He is also an elected member of National Academy of Engineering. He has published more than 375 papers, co-authored books on Laser Chemical Vapor Deposition and Laser Materials Processing. He also edited/co-edited 10 books on topics related to laser materials processing and Mechanical Engineering. He holds 17 U.S. patents. He is taking his research to market by commercializing DMD through a start up called POM Group Inc. DMD systems are installed in four continents. Some of his laser welding patents are licensed to Ford Motor Company. Dr. Mazumder has received numerous awards and honors for his research including, Schawlow Award for seminal contribution to laser application research from Laser Institute of America in 2003, William T. Ennor Award for manufacturing from ASME in 2006, Adams Memorial Membership award from American Welding Society in 2007, Thomas A. Edison Patent Award from ASME in 2010 for inventing First closed loop Direct Metal Deposition system, which will significantly enhance some aspect of Mechanical Engineering, Distinguished University Award in 2012 from the University of Michigan. Manufacturing Engineer of the Year (1986) from Society of Manufacturing Engineer, University Scholar (1985) and Xerox (1987) award from University of Illinois. He is also Fellow of American Society of Mechanical Engineers (ASME). American Society of Metals (ASM) and Laser Institute of America (LIA). He served as the president of the Laser Institute of America in the year 2000. Dr Mazumder was Editor in Chief of the Journal of Laser Applications until December 2009. Advances in Optical Diagnostics for Laser Processing Jyoti Mazumder, University of Michigan

Patterning of gold-black infrared absorbing films by stencil lithography and hardening by polymer infusion is reported. Gold black nano-structured films are deposited through a thin metal shadow mask in a thermal evaporator in ~400 mTorr pressure of inert gas, followed by ethyl cyanoacrylate fuming through the same mask to produce rugged IR absorptive patterns of ~100 micron scale dimensions. Infrared absorptivity is determined by transmission and reflectivity measurements using a Fourier spectrometer and infrared microscope. Results indicate that the optimized hardening process reduces the usual degradation of the absorptivity with age. This work has potential application to infrared array bolometers.

A mid-infrared intracavity laser absorption spectrometer based on an external cavity multi-mode quantum cascade laser is combined with a scanning Fabry-Perot interferometer is used as tunable narrow band transmission filter to analyze the laser emission spectrum. Sensitivity as a trace gas detector at 8.1 micron wavelengths has been demonstrated based on a weak water vapor line at an absorption coefficient of 1 x 10-5 cm-1. For molecules of reasonably strong absorption cross section (10-17 cm2), this corresponds to a detection limit of 40 ppb.

Conducting polymers are potentially useful materials in sensor applications. Polyaniline is one of the most promising of these materials due to high conductivity and plasma frequencies as high as the mid-infrared. The application of this material is still limited because of low conductivity. In this paper, we chemically prepared a composite of co-doped polyaniline with hydrochloric acid and MSA (methane sulfonic acid) in aqueous solution with both colloidal and nano-graphite. Solutions of the composite material were prepared in m-cresol and NMP (N-mthyle-2-pyrrolidone), which are common organic solvents. This approach resulted in material with conductivity higher than either intrinsic polyaniline or graphite alone. The solution of the composite was spin coated on suitable substrates. The thicknesses of the films were measured using atomic force microscope (AFM). Fourier transform infrared spectra (FTIR) and micro-Raman spectra were collected to confirm the composition and determine the infrared thickness. Surface plasmon resonances for grating patterns of this composite material were calculated using experimental determined infrared (IR) ellipsometry data. The goal is to identify a material which has potential application for surface plasmons resonance sensing with high sensitivity and selectivity in IR range.

The semimetal antimony, with a plasma frequency ~80 times less than that of gold, is potentially useful as a host for infrared surface polaritons (SPs). Relevant IR SP properties, including the frequency-dependent propagation length and penetration depths for fields into the media on either side of the interface, were determined from optical constants measured on optically-thick thermally-evaporated Sb films over the wavelength range 1 to 40 μm. Plasma and carrier relaxation frequencies were determined from Drude-model fits to these data. The real part of the permittivity is negative for wavelengths beyond 11 μm. Distinct resonant decreases in specular reflected intensity were observed for Sb lamellar gratings in the wavelength range of 6 to 11 μm, where the real part of the permittivity is positive. Both resonance angles and the angular reflectance spectral line shapes are in agreement with theory for excitation of bound surface electromagnetic waves (SPs). Finite element method (FEM) electrodynamic simulations indicate the existence of SP modes under conditions matching the experiments. FEM results also show that such waves depend on having a significant imaginary part of the permittivity, as has been noted earlier for the case of surface exciton polaritons.

As an aid in interpreting data from space far-infrared (far-IR) missions, such as the Herschel Space Observatory with its Photodetector Array Camera and Spectrometer, this paper presents spectroscopic studies of selected naturally occurring terrestrial sulphide minerals in the wavelength range 15-250 mu m. The data can also be used to support the return from other, both past and planned, IR space missions, such as the Infrared Space Observatory, Spitzer, SOFIA, SPiCA and Millimetron. In this study, we present far-IR spectra for 11 natural sulphide minerals in the form of dispersed powders of micron particle dimensions. Samples of various sulphides from the American Museum of Natural History mineral collection were selected based on criteria of diversity and potential astrophysical relevancy, based on their identification in Stardust, in stratospheric interplanetary dust particle samples, or in meteorites. Mineral species include digenite, galena, alabandite, sphalerite, wurtzite, covellite, pyrrhotite, pyrite, marcasite, chalcopyrite and stibnite. Most of the sulphides examined possess prominent and characteristic features in the far-IR range. Spectra obtained are compared to those available from previous studies. Far-IR peak frequencies and mass absorption coefficient values are tabulated. Effects of particle size distribution, low temperature, and provenance on IR spectra are demonstrated for selected samples.

Mineral spectra in the far-IR region are highly characteristic of mineral group, crystal structure and chemical composition. For slightly more than 10 years has far-IR spectroscopy become useful for identifying the mineralogy of cosmic dust populations. Now attempts to identify some common minerals having prominent far-IR features within the dust associated with various astronomical objects, such as the circumstellar dust of AGB stars, that of Young Stellar Objects, Planetary Nebulae, protoplanetary and debris discs, and comets, are being undertaken. In addition to the currently operating far-IR/sub-mm Herschel Space Observatory, several others, both past and planned, IR space missions, such as ISO, Spitzer, SOFIA, SPICA, and Millimetron, are to be mentioned. To support the analysis of data return from those missions, the building of a database of laboratory far-IR spectra of terrestrial mineral analogs, representing a wide range of mineral groups, especially at conditions relevant to those in space (e.g. at cryogenic temperatures) is desirable and timely. In this connection, we have collected mass absorption coefficient spectra of micron-sized powders for more than 150 naturally occurring astrophysically-relevant terrestrial minerals in the wavelength range 15 250 μm. These include over 20 oxides and hydroxides; a variety of sulfides of Me(1-x)S and MeS(1-x) families; carbonates (e.g. Fig.1 (right)); garnets; phenakites; olivines over the full Fig.1 (left) spectra of the phyllosilicates, mica subgroup; compositional range from fayalite Fe2SiO4 (right) examples of spectra for hydrated and acid carbonates. to forsterite Mg2SiO4; pyroxenes including jadeite NaAlSi O 2 6, aegirine NaFe Si O and 3+ 2 6 the enstatite MgSiO3 – ferrosilite Fe SiO and the diopside CaMgSi O augite Ca(Mg,Fe)Si O – hedenbergite CaFeSi O series 2+ 3