This PDF file contains the front matter associated with SPIE Proceedings Volume 9855, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

An extremely miniaturized scanning grating spectrometer at the size of a sugar cube has been developed at Fraunhofer IPMS. To meet the requirements for the integration into a mobile phone a new system approach has been pursued. The key component within the system is a silicon-based deflectable diffraction grating with an integrated driving mechanism. A first sample of the new spectrometer was built and characterized. It was found to have a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The results show that the performance of the new MEMS spectrometer is in good agreement with the requirements for mobile phone integration.

During the last several years, the world has moved from wired communications (e.g., a wired ethernet, wired telephone) to wireless communications (e.g., cell phones, smart phones, tablets). However, data acquisition has lagged behind and for the most part, data in laboratory settings are still acquired using wired communications (or even plug in boards). In this paper, approaches that can be used for wireless data acquisition are briefly discussed using a conceptual model of a future, mobile, portable micro-instrument as an example. In addition, past, present and near-future generations of communications are discussed; processors, operating systems and benchmarks are reviewed; networks that may be used for data acquisition in the field are examined; and, the possibility of connecting sensor or micro-instrument networks to the internet of things is postulated.

We had already proposed and reported the little-finger size hyperspectral-camera that was able to be applied to visible and infrared lights. The proposed method has been expected to be mounted on smartphones for healthcare sensors, and unmanned air vehicles such as drones for antiterrorism measures or environmental measurements. In this report, we will mention the trial product of the thumb size apparatus whose lens diameter was 5[mm]. The proposed Fourier spectroscopic imager is a kind of wavefront-division and common-path phase-shift interferometers. We installed the relative inclined phase-shifter onto optical Fourier transform plane of infinity corrected optical systems. The infinity corrected optical systems was configured with an objective lens and a cylindrical imaging lens. The relative inclined phase-shifter, what was made from a thin glass less than 0.3[mm] thick, had the wedge-prism and cuboid-glass region, because half surface of a thin glass was polished at an oblique angle of around 1[deg.]. The collimated half flux of objective beams derived from single-bright points on objective surface penetrate through the wedge prism and the cuboid glass respectively. These two beams are interfered each other and form the infererogram as spatial fringe patterns. In this case, the horizontal axis on 2-dimensional light receiving device is assigned to the amount of phase-shift. And also the vertical axis is assigned to the imaging coordinates on a line view field. Thus, by installing thin phase-shifter onto optical Fourier transform plane, the line spectroscopic imager, what obtains 1 dimensional spectral character distributions, were able to be realized.

We proposed the snapshot-type Fourier spectroscopic imaging for smartphone that was mentioned in 1st. report in this conference. For spectroscopic components analysis, such as non-invasive blood glucose sensors, the diffuse reflection lights from internal human skins are very weak for conventional hyperspectral cameras, such as AOTF (Acousto-Optic Tunable Filter) type. Furthermore, it is well known that the spectral absorption of mid-infrared lights or Raman spectroscopy especially in long wavelength region is effective to distinguish specific biomedical components quantitatively, such as glucose concentration. But the main issue was that photon energies of middle infrared lights and light intensities of Raman scattering are extremely weak. For improving sensitivity of our spectroscopic imager, the wide-field-stop & beam-expansion method was proposed. Our line spectroscopic imager introduced a single slit for field stop on the conjugate objective plane. Obviously to increase detected light intensities, the wider slit width of the field stop makes light intensities higher, regardless of deterioration of spatial resolutions. Because our method is based on wavefront-division interferometry, it becomes problems that the wider width of single slit makes the diffraction angle narrower. This means that the narrower diameter of collimated objective beams deteriorates visibilities of interferograms. By installing the relative inclined phaseshifter onto optical Fourier transform plane of infinity corrected optical systems, the collimated half flux of objective beams derived from single-bright points on objective surface penetrate through the wedge prism and the cuboid glass respectively. These two beams interfere each other and form the infererogram as spatial fringe patterns. Thus, we installed concave-cylindrical lens between the wider slit and objective lens as a beam expander. We successfully obtained the spectroscopic characters of hemoglobin from reflected lights from human fingers.

The distributed networks for information collection of chemical components with high-mobility objects, such as drones or smartphones, will work effectively for investigations, clarifications and predictions against unexpected local terrorisms and disasters like localized torrential downpours. We proposed and reported the proposed spectroscopic line-imager for smartphones in this conference. In this paper, we will mention the wide-area spectroscopic-image construction by estimating 6 DOF (Degrees Of Freedom: parallel movements=x,y,z and rotational movements=θ_x, θ_y, θ_z) from line data to observe and analyze surrounding chemical-environments. Recently, smartphone movies, what were photographed by peoples happened to be there, had worked effectively to analyze what kinds of phenomenon had happened around there. But when a gas tank suddenly blew up, we did not recognize from visible-light RGB-color cameras what kinds of chemical gas components were polluting surrounding atmospheres. Conventionally Fourier spectroscopy had been well known as chemical components analysis in laboratory usages. But volatile gases should be analyzed promptly at accident sites. And because the humidity absorption in near and middle infrared lights has very high sensitivity, we will be able to detect humidity in the sky from wide field spectroscopic image. And also recently, 6-DOF sensors are easily utilized for estimation of position and attitude for UAV (Unmanned Air Vehicle) or smartphone. But for observing long-distance views, accuracies of angle measurements were not sufficient to merge line data because of leverage theory. Thus, by searching corresponding pixels between line spectroscopic images, we are trying to estimate 6-DOF in high accuracy.

This paper demonstrates a mobile phone- compatible hyperspectral imager based on a tunable MEMS Fabry-Perot interferometer. The realized iPhone 5s hyperspectral imager (HSI) demonstrator utilizes MEMS FPI tunable filter for visible-range, which consist of atomic layer deposited (ALD) Al₂O₃/TiO₂-thin film Bragg reflectors. Characterization results for the mobile phone hyperspectral imager utilizing MEMS FPI chip optimized for 500 nm is presented; the operation range is λ = 450 – 550 nm with FWHM between 8 – 15 nm. Also a configuration of two cascaded FPIs (λ = 500 nm and λ = 650 nm) combined with an RGB colour camera is presented. With this tandem configuration, the overall wavelength tuning range of MEMS hyperspectral imagers can be extended to cover a larger range than with a single FPI chip. The potential applications of mobile hyperspectral imagers in the vis-NIR range include authentication, counterfeit detection and potential health/wellness and food sensing applications.

This study examines parametric modeling of NIR reflectivity spectra for dyed fabrics, which provides for both their inverse and direct modeling. The dye considered for prototype analysis is triarylamine dye. The fabrics considered are camouflage textiles characterized by color variations. The results of this study provide validation of the constructed parametric models, within reasonable error tolerances for practical applications, including NIR spectral characteristics in camouflage textiles, for purposes of simulating NIR spectra corresponding to various dye concentrations in host fabrics, and potentially to mixtures of dyes.

Studies on the application of a parabolic reflector in spontaneous Raman scattering for low background Raman analysis of gas samples are reported. As an effective signal enhancing sample cell, photonic bandgap fiber (HC-PBF) or metallined capillary normally result in a strong continuous background in spectra caused by the strong Raman/fluorescence signal from the silica wall and the polymer protective film. In order to obtain enhanced signal with low background, a specially designed sample cell with double-pass and large collecting solid angle constructed by a parabolic reflector and a planar reflector was applied, of which the optical surfaces had been processed by diamond turning and coated by silver film and protective film of high-purity alumina. The influences of optical structure, polarization characteristic, collecting solid-angle and collecting efficiency of the sample cell on light propagation and signal enhancement were studied. A Raman spectrum of ambient air with signal to background ratio of 94 was acquired with an exposure time of 1 sec by an imaging spectrograph. Besides, the 3σ limits of detection (LOD) of 7 ppm for H₂, 8 ppm for CO₂ and 12 ppm for CO were also obtained. The sample cell mainly based on parabolic reflector will be helpful for compact and high-sensitive Raman system.

During the last years, 3d printing for rapid prototyping using additive manufacturing has been receiving increased attention in the technical and scientific literature including some Chemistry-related journals. Furthermore, 3D printing technology (defining size and resolution of 3D objects) and properties of printed materials (e.g., strength, resistance to chemical attack, electrical insulation) proved to be important for chemistry-related applications. In this paper these are discussed in detail. In addition, application of 3D printing for development of Micro Plasma Devices (MPDs) is discussed and 2d-profilometry data of a 3D printed surfaces is reported. And, past and present chemistry and bio-related applications of 3D printing are reviewed and possible future directions are postulated.

We report the single-mode operation of mid-infrared distributed-feedback (DFB) interband cascade lasers (ICLs) with contacts that cover only a fraction of the top surface of the laser ridge. This reduces the optical loss from the metal for the GaSb-relevant device configuration in which the grating is fabricated in the top layer of the DFB laser. Continuous wave (cw) room-temperature operation in a single spectral mode is observed for contact duty cycles as small as 14% when the width of the contact is fixed at 10 μm. The reduced contact duty cycle results in a factor of 2 decrease in the threshold current. The highest slope efficiency is observed for a contact duty cycle of 33%, for which the cw single-mode output power is as high as 6.8 mW.

A device based on Tunable Diode Laser Absorption Spectroscopy has been developed for non-invasive evaluation of gaseous oxygen concentration inside packed food containers. This work has been done in the context of the SAFETYPACK European project in order to enable full, automated product testing on a production line. The chosen samples at the end of the manufacturing process are modified atmosphere bags of processed mozzarella, in which the target oxygen concentration is required to be below 5%. The spectrometer allows in-line measurement of moving samples which are passing on a conveyor belt, with an optical layout optimized for bags made of a flexible scattering material, and works by sensing the gas phase in the headspace at the top of the package. A field applicable method for the calibration of this device has been identified and validated against traditional, industry standard, invasive measurement techniques. This allows some degrees of freedom for the end-user regarding packaging dimensions and shape. After deployment and setup of the instrument at the end-user manufacturing site, performance has been evaluated on a different range of samples in order to validate the choice of electro optical and geometrical parameters regarding sample handling and measurement timing at the actual measurement conditions.

Compared to the near infrared, many technologically and industrially relevant gas species have more than an order of magnitude higher absorption features in the mid-infrared (MIR) wavelength range. These species include for example important hydrocarbons (methane, acetylene), nitrogen oxides and sulfur oxides. Tunable laser absorption spectroscopy (TLAS) has proven to be a versatile tool for gas sensing applications with significant advantages compared to other techniques. These advantages include real time measurement, standoff detection and ruggedness of the sensor. We present interband cascade lasers (ICLs), which have evolved into important laser sources for the MIR spectral range from 3 to 7 μm. ICLs achieve high efficiency by cascading optically active zones whilst using interband transitions, so they combine common diode laser as well as quantum cascade laser based technologies. Our application grade singlemode distributed feedback devices operate continuous wave at room temperature and are offering several features especially useful for high performance TLAS applications like: side mode suppression ratio of > 30 dB, continuous tuning ranges up to 30 nm, low threshold power densities and low overall power consumption. The devices are typically integrated in a thermoelectrically cooled TO-style package, hermetically sealed using a cap with anti-reflection coated window. This low power consumption as well as the compact size and ruggedness of the fabricated laser sources makes them perfectly suited for battery powered portable solutions for in field spectroscopy applications.

The necessity for monitoring of changing levels of greenhouse gases (GHGs) is clearly evident now more than ever. This has led to large deployments of analytical devices to most remote locations as well as the most densely populated regions around the world. Both large and small scale projects have forced new and old technologies to be pushed to their limits to obtain the highest performing measurements while maintaining a cost effective way to remotely monitor changes in atmospheric concentrations. In order to accomplish these strict guidelines, we present a low-power cavity ring-down spectrometer that measures Carbon Dioxide, Methane and water vapor which can achieve measurements with precisions lower than 20ppb of CO₂ and 50ppt of CH₄. Comparing to hundreds of watts needed in conventional CRDS design, we demonstrate that the high performance can be achieved with less than 25W. Stability of these measurements has allowed for averaging times of up to 3hr, yielding measurements of methane concentrations with precisions down to 40ppt. This is accomplished utilizing an FSR based frequency scale to determine an absolute frequency scale for these absorption features. Taking advantage of this faster, and less costly measurement technique of CRDS shows future promise with applications spanning scientific and industrial analyses, from isotopes to trace gases.

We describe here a tunable long wave infrared (LWIR) band filter based on the guided mode resonant filter (GMRF) effect. The device consists of a subwavelength dielectric grating sandwiched between planar layers of contrasting dielectric materials. Using a rigorous electromagnetic design and analysis method we demonstrate how a strong narrow band reflectance can be induced. Moreover, the resonant wavelength can be easily tuned over the entire 8-12 micron band by mechanically tilting the device with respect to the optical axis. Simulation and experimental results are presented demonstrating the effectiveness of the device.

Hyperspectral imaging (HSI) is a valuable tool for the investigation and analysis of targets in complex background with a high degree of autonomy. HSI is beneficial for the detection of threat materials on environmental surfaces, where the concentration of the target of interest is often very low and is typically found within complex scenery. Two HSI techniques that have proven to be valuable are Raman and shortwave infrared (SWIR) HSI. Unfortunately, current generation HSI systems have numerous size, weight, and power (SWaP) limitations that make their potential integration onto a handheld or field portable platform difficult. The systems that are field-portable do so by sacrificing system performance, typically by providing an inefficient area search rate, requiring close proximity to the target for screening, and/or eliminating the potential to conduct real-time measurements. To address these shortcomings, ChemImage Sensor Systems (CISS) is developing a variety of wide-field hyperspectral imaging systems. Raman HSI sensors are being developed to overcome two obstacles present in standard Raman detection systems: slow area search rate (due to small laser spot sizes) and lack of eye-safety. SWIR HSI sensors have been integrated into mobile, robot based platforms and handheld variants for the detection of explosives and chemical warfare agents (CWAs). In addition, the fusion of these two technologies into a single system has shown the feasibility of using both techniques concurrently to provide higher probability of detection and lower false alarm rates. This paper will provide background on Raman and SWIR HSI, discuss the applications for these techniques, and provide an overview of novel CISS HSI sensors focused on sensor design and detection results.

Imec has developed a process for the monolithic integration of optical filters on top of CMOS image sensors, leading to compact, cost-efficient and faster hyperspectral cameras. Different prototype sensors are available, most notably a 600- 1000 nm line-scan imager, and two mosaic sensors: a 4x4 VIS (470-620 nm range) and a 5x5 VNIR (600-1000 nm). In response to the users’ demand for a single sensor able to cover both the VIS and NIR ranges, further developments have been made to enable more demanding applications. As a result, this paper presents the latest addition to imec’s family of monolithically-integrated hyperspectral sensors: a line scan sensor covering the range 470-900 nm. This new prototype sensor can acquire hyperspectral image cubes of 2048 pixels over 192 bands (128 bands for the 600- 900 nm range, and 64 bands for the 470-620 nm range) at 340 cubes per second for normal machine vision illumination levels.

Traditional spectral unmixing involves intense signal processing applied on multispectral or hyperspectral data captured from an imaging device, which is highly time-consuming. In this article, a novel method, namely "optical unmixing", is proposed to alleviate the post processing effort by replacing the heavy computation with a spectrally tunable light source. By choosing spectral features of the light source intelligently, the abundance map of each material can be retrieved with minimum computation from gray value images captured by a normal camera. For n unknown endmembers, 3n + 1 measurements are required to retrieve the abundance maps with proposed algorithms.

Miniature spectrometers have been widely developed in various academic and industrial applications such as bio-medical, chemical and environmental engineering. As a family of spectrometers, optical filter-array based spectrometers fabricated using CMOS or Nano technology provide miniaturization, superior portability and cost effectiveness. In filterarray based spectrometers, the resolution which represents the ability how closely resolve two neighboring spectra, depends on the number of filters and the characteristics of the transmission functions (TFs) of the filters. In practice, due to the small-size and low-cost fabrication, the number of filters is limited and the shape of the TF of each filter is nonideal. As a development of modern digital signal processing (DSP), the spectrometers are equipped with DSP algorithms not only to alleviate distortions due to unexpected noise or interferences among filters but also reconstruct the original signal spectrum. For a high-resolution spectrum reconstruction by the DSP, the TFs of the filters need to be sufficiently uncorrelated with each other. In this paper, we present a design of optical thin-film filters which have the uncorrelated TFs. Each filter consists of multiple layers of high- and low-refractive index materials deposited on a substrate. The proposed design helps the DSP algorithm to improve resolution with a small number of filters. We demonstrate that a resolution of 5 nm within a range from 500 nm to 1100 nm can be achieved with only 64 filters.