This PDF file contains the front matter associated with SPIE Proceedings Volume 8992 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Traditional design methods for flow cytometers and other complex biophotonic systems are increasingly recognized as a major bottleneck in instrumentation development. The many manual steps involved in the analysis and translation of the design, from optical layout to a detailed mechanical model and ultimately to a fully functional instrument, are laborintensive and prone to wasteful trial-and-error iterations. We have developed two complementary, linked technologies that address this problem: one design tool (LiveIdeas™) provides an intuitive environment for interactive, real-time simulations of system-level performance; the other tool (BeamWise™) automates the generation of mechanical 3D CAD models based on those simulations. The strength of our approach lies in a parametric modeling strategy that breaks boundaries between engineering subsystems (e.g., optics and fluidics) to predict critical behavior of the instrument as a whole. The results: 70 percent reduction in early-stage project effort, significantly enhancing the probability of success by virtue of a more efficient exploration of the design space.

Point-of-use chemical analysis holds tremendous promise for a number of industries, including agriculture, recycling, pharmaceuticals and homeland security. Near infrared (NIR) spectroscopy is an excellent candidate for these applications, with minimal sample preparation for real-time decision-making. We will detail the development of a golf ball-sized NIR spectrometer developed specifically for this purpose. The instrument is based upon a thin-film dispersive element that is very stable over time and temperature, with less than 2 nm change expected over the operating temperature range and lifetime of the instrument. This filter is coupled with an uncooled InGaAs detector array in a small, rugged, environmentally stable optical bench ideally suited to unpredictable environments. The resulting instrument weighs less than 60 grams, includes onboard illumination and collection optics for diffuse reflectance applications in the 900-1700 nm wavelength range, and is USB-powered. It can be driven in the field by a laptop, tablet or even a smartphone. The software design includes the potential for both on-board and cloud-based storage, analysis and decision-making. The key attributes of the instrument and the underlying design tradeoffs will be discussed, focusing on miniaturization, ruggedization, power consumption and cost. The optical performance of the instrument, as well as its fit-for purpose will be detailed. Finally, we will show that our manufacturing process has enabled us to build instruments with excellent unit-to-unit reproducibility. We will show that this is a key enabler for instrumentindependent chemical analysis models, a requirement for mass point-of-use deployment.

In this work, we study the performance of a scanning Fabry-Perot interferometer based laser Doppler velocimeter (sFPILDV) and compare two candidate 1.5 um single-frequency laser sources for the system – a fiber laser (FL) and a semiconductor laser (SL). We describe a straightforward calibration procedure for the sFPI-LDV and investigate the effect of different degrees of laser frequency noise between the FL and the SL on the velocimeter’s performance.

Fabrication and characterization of the surface plasmon resonance (SPR) based three channel fiber optic sensor for multiple parameter sensing have been carried out. Three probes have been prepared on a single fiber by coating silver, gold and copper along with one high index titanium oxide on three unclad well separated portions of the fiber respectively. SPR spectra have been recorded for aqueous sucrose solutions of varying refractive indices. The sensor relies on wavelength interrogation technique. To verify the results, simulations have been carried out using a multilayer model and geometrical optics. The experimental and simulated results have been found to match qualitatively. The present sensor can simultaneously sense multiple parameters/analytes at a single platform.

A design of SPR based fiber optic ethanol biosensor is presented by using enzyme alcohol dehydrogenase and nicotinic acid. The sensing probe is fabricated with the coating of 40 nm thin film of silver metal and immobilization of alcohol dehydrogenase and nicotinic acid by gel entrapment method over unclad core of a multimode optical fiber. The SPR spectra of ethanol samples of concentrations ranging from 0 mM to 10 mM prepared in buffer have been recorded. The sensor works on the spectral interrogation technique and operates in the visible range of the spectrum. The SPR curves are blue shifted with the increasing concentration of ethanol and the sensitivity of the sensor decreases with the increasing concentration of ethanol. The sensor has many advantages such as fast response, stability, small probe size, low cost and can be used for remote/online monitoring.

A novel all fiber-optic temperature sensor based on graphene film coated on a side polished fiber (SPF) was demonstrated. Significantly enhanced interaction between the propagating light and the graphene film can be achieved via strong evanescent light of the SPF. The experiments shows that the strong interaction results in temperature sensing with a dynamic optical power variation of 11.3dB in SPF. The novel temperature fiber sensor possesses a linear correlation coefficient of 99.4%, a sensitivity of 0.13dB/°C, a precision of better than 0.03°C. Furthermore, the graphene-based all fiber-optic temperature sensor is easy to fabricate, compatible with fiber-optic systems and possesses high potentiality in photonics applications such as all fiber-optic temperature sensing network.

VTT has developed Fabry-Pérot Interferometers (FPI) for visible and infrared wavelengths since 90’s. Here we present two new platforms for mid-infrared gas spectroscopy having a large optical aperture to provide high optical throughput but still enabling miniaturized instrument size. First platform is a tunable filter that replaces a traditional filter wheel, which operates between wavelengths of 4-5 um. Second platform is for correlation spectroscopy where the interferometer provides a comb-like transmission pattern mimicking absorption of diatomic molecules at the wavelength range of 4.7-4.8 um. The Bragg mirrors have 2-4 thin layers of polysilicon and silicon oxide.

The accurate knowledge about the refractive index of optical materials is crucial for the production of high performance optical components. It is known that the highest accuracy of refractive index measurements can be achieved with goniometric measurements of prisms prepared from the optical material. The most common approach is the method of minimum deviation of Newton-Fraunhofer. The apex angle is measured with a high precision in reflection with an autocollimator and the angle of refraction is measured in transmission using an additional collimator. There are also other goniometric approaches like the Abb´e method employing a purely reflective setup with an autocollimator. In this paper we discuss and compare the two different goniometric approaches.

The response of an optical systems to a point source, known as the point-spread function (PSF), represents one of the most fundamental characteristics of an optical system. The PSF varies as a function of source spectral composition as well as position with respect to the optical axis. PSF characterization of optical systems can be used to predict their performance in imaging and non-imaging applications. In this paper we describe an electro-optical setup for automated characterization of the PSF of optical systems over a broad range of operating conditions and radiance levels, with spectral compositions ranging from ultraviolet (UV) to long-wave infrared (LWIR). Our test setup includes interchangeable radiance sources and computer controlled motion stages which allows for automated characterization of the optical system under test. The software-controlled characterization process provides quantitative analysis of the system’s chromatic and monochromatic aberrations, including axial chromatism, field curvature, and field distortion. The developed process also defines system level characteristics, such as relative illumination, field of regard and magnification. Finally, we demonstrate characterization of the operational dynamic range of imaging and non-imaging sensors employing the described setup, including their threshold responsivity, as well as their saturation performance under intense illumination conditions.

With the upcoming Ultra High Definition (UHD) cameras, the accurate alignment of optical systems with respect to the UHD image sensor becomes increasingly important. Even with a perfect objective lens, the image quality will deteriorate when it is poorly aligned to the sensor. For evaluating the imaging quality the Modulation Transfer Function (MTF) is used as the most accepted test. In the first part it is described how the alignment errors that lead to a low imaging quality can be measured. Collimators with crosshair at defined field positions or a test chart are used as object generators for infinite-finite or respectively finite-finite conjugation. The process how to align the image sensor accurately to the optical system will be described. The focus position, shift, tilt and rotation of the image sensor are automatically corrected to obtain an optimized MTF for all field positions including the center. The software algorithm to grab images, calculate the MTF and adjust the image sensor in six degrees of freedom within less than 30 seconds per UHD camera module is described. The resulting accuracy of the image sensor rotation is better than 2 arcmin and the accuracy position alignment in x,y,z is better 2 μm. Finally, the process of gluing and UV-curing is described and how it is managed in the integrated process.

Spectral reflection (R) and transmission (T) are the fundamental measurements for characterizing the optical properties of materials and optical coatings. Historically the complete characterization of optical materials and coatings for precision optics has been largely accomplished on the basis of normal and near normal incidence measurements due to the experimental simplicity of such an approach. This simplicity, however, is not without compromise. Normal incidence transmission measurements are typically conducted within the sample chamber of a spectrophotometer whilst near normal reflectance measurements require the use of a suitable reflectance accessory. A consequence of this approach is that there is never any guarantee that reflectance and transmission measurements are made from exactly the same patch on the sample due to sample repositioning during the significant changes in instrument configuration between R and T measurements. Multi-angle Photometric Spectroscopy (MPS) measures the reflectance and/or transmittance of a sample across a range of angles (θ_i) from near normal to oblique angles of incidence (AOI). A recent development by Agilent Technologies, the Cary 7000 Universal Measurement Spectrophotometer (UMS) combines both reflection and transmission measurements from the same patch of a sample’s surface, without sample repositioning, in a single automated platform for angles of incidence in the range 5°≤|θ_i|≤85° (i.e. angles on either side of beam normal noted as +/-). In this paper we describe the use of MPS on the UMS with rotational (Φ) and radial (ζ) sample positioning control. MPS(θ_i,Φ,ζ) provides for automated unattended multi-angle R/T analysis of multiple individual samples (up to 32 pieces, 1 inch diameter) or mapping of single larger diameter samples (of up to 8 inch diameter). Examples are provided which demonstrate reduced cost-per-analysis in high volume multiple sample testing as well as spatial spectroscopic information obtained on large diameter samples.

The ZOOM Spectra spectrometer is the first fully integrated system to benefit from the disruptive SWIFTS technology, providing a high-resolution high-rate solution for the characterization of lasers. It allows for the first time a dynamic real-time view of their behavior. The instrument is an alliance of integrated guided optics, groundbreaking nanotechnologies, microelectronics and advanced software. The device has been designed to be a rapid solution for checking the tuning of a laser, the existence of hopping modes and the correct suppression of a side mode. Their performances are particularly valuable for analysis of custom sources such as Distributed Feedback (DFB) lasers, Vertical Cavity Surface Emitting Lasers (VCSELs), External Cavity Lasers (ECL), or Optical Parametric Oscillator (OPO) sources.

An optical fiber with a transversely disordered yet longitudinally invariant refractive index profile can propagate a beam of light using transverse Anderson localization. A launched beam of light into the disordered optical fiber expands till it reaches its localization radius beyond which it propagates without further expansion. In contrast to a conventional single-core optical fiber in which a propagating beam of light can only couple to and propagate in the core, the beam of light can be coupled to any point at the tip of the disordered fiber. This property originated from the localized highly multimodal property of disordered optical fibers that can be used for high quality optical image transport. We experimentally compare the quality of the transported images in the disordered polymer optical fibers with those transported through the multicore imaging fibers, as well as conventional single core fibers. The impacts of source wavelength and refractive index difference between the disordered sites on the quality of the transported images in the disordered optical fibers is studied numerically. The role of randomness in improving the quality of transported images is investigated by comparing the full vectorial modes of a disordered fiber with those in a periodic multicore fiber.

The paper gives an introduction into vacuum viewports and its stress introduced birefringence effects. The effect of the stress induced birefringence is measured for viewports of different thicknesses under vacuum conditions. Line scans across the viewports are done to investigate heterogeneity effects also. The variation of thickness is realized with elastomer sealed viewports. In order to compare those results measurements are done also with thermally sealed viewports as well as adhesively sealed viewports.

We present a novel optical system for distance measurement based on the combination of optical time-of-flight metrology and digital holography. In addition absolute calibration of the measurement results is performed by a sideband modulation technique. For the time-of-flight technique a diode laser (1470 nm) is modulated sinusoidally (128 MHz). The light reflected and scattered by an object is detected by an avalanche-photo-diode. The phase difference between the sent and detected modulation is a measure for the distance between the sensor and the object. This allows for distance measurements up to 1.17 m with resolutions of ~2 mm. The interferometric setup uses 4 whispering-gallery-mode lasers to perform multiwavelengths-holographic distance measurements. The four wavelengths span the range from 1547 nm to 1554 nm. The unambiguous measurement measurement-range of the interferometric setup is approx. 7 mm while resolutions of 0.6 μm are observed. Both setups are integrated into one setup and perform measurements synchronously. Exact knowledge of the frequency differences of hundreds of GHz between the four lasers is crucial for the interferometric fine scale measurement. For this aim the light of the lasers is phase-modulated with frequencies of 36 GHz and 40 GHz to produce optical sidebands of higher order, thus generating beat signals in the hundreds-of-MHz regime, which can be measured electronically. The setup shows a way to measure distances in the meter range with sub-micron resolution.

The development of ultra-broadband oscilloscopes is mainly governed by the needs of future telecom networks. But other applications are requesting the availability of true real-time acquisition oscilloscopes. Systems able to be used in single-shot operation are of prime interest for Inertial Confinement Fusion (ICF) and for the related R&D for plasma physics. We previously demonstrate a single-shot, 100GHz design of an all-optical sampling oscilloscope at 1μm (MULO). This laboratory system has been improved in stability and compactness to make an all-in-one box prototype. More, by the addition of an opto-electro-optics (OEO) sub-system at the input, we developed the ability to use this oscilloscope to analyze an electrical input signal up to 60GHz. This new integrated subset also increases the range of wavelength for optical input signal, from 300nm up to 2μm. Furthermore, it allows the use of inexpensive opto-electronic components at telecom wavelength for this system regardless of the signal to be analysed. In parallel with these improvements, by optimizing the heart of the system, we get a very high sampling rate, up to 500Gs/s and more; this allows considering much higher bandwidths in the future. In this talk, we will present latest developments and integration of this system. It will also allow us to give more details on the innovative OEO sub-system.

The steady progress in photonic components in terms of cost-to-performance ratio, maturity and robustness opens new avenues for the commercial deployment of photonic sensor systems in a wide range of industrial applications. Advanced sensing can be used to optimize complex processes and thereby enable significant savings in energy consumption. Three cases of robust photonic instrumentation for process optimization and quality control in manufacturing industries are presented: improved metal recycling with laser-induced breakdown spectroscopy, quality control in precision machining by white-light interferometry with optical fiber probes embedded in machining tools, and process optimization in steel foundries by stand-off temperature measurements in blast furnaces with optical fiber lances and spectral analysis techniques. Each of these methods utilizes a low-cost spectrometer, and requires dedicated calibration and signal processing methods to guarantee robust operation in industrial environments with varying conditions. Experimental results are presented, including on-line steel alloy analysis with correct classification rates in excess of 95%, distance measurements with axial resolution of +/- 2nm over a 75μm range, and continuous temperature monitoring of molten steel in oxygen blast furnaces with temperature measurement accuracy better than 1%.

Adopting opto-piezoelectric materials, which utilized optical illumination pattern to effect the spatial force distribution induced by piezoelectric materials, to ultrasonic parking sensors and optofluidic chips represent a new research direction in industrial sub-system development. To accommodate performance requirements include wide bandwidth, ultrahigh precision, non-contact measurement mode, linear and angular measurement, etc. associated with the evaluation of the above-mentioned systems, a laser Doppler interferometer was implemented to facilitate the system development. The completely orthogonal alignment design configuration, system performance verified, signal processing algorithms developed as well as the experimental results obtained were all discussed in this paper. Emphasis is on the experimental data obtained from the interferometer and the design changes developed based on the metrology outcome. The system performance improvements induced by the experimental verification achieved by the interferometer were discussed in detail.

In this work we investigate the performance of a monostatic coherent lidar system in which the transmit beam is under the influence of primary phase aberrations: spherical aberration (SA) and astigmatism. The experimental investigation is realized by probing the spatial weighting function of the lidar system using different optical transceiver configurations. A rotating belt is used as a hard target. Our study shows that the lidar weighting function suffers from both spatial broadening and shift in peak position in the presence of aberration. It is to our knowledge the first experimental demonstration of these tendencies. Furthermore, our numerical and experimental results show good agreement. We also demonstrate how the truncation of the transmit beam affects the system performance. It is both experimentally and numerically proven that aberration effects have profound impact on the antenna effciency, the optimum truncation of the transmit beam and the spatial sensitivity of a CW coherent lidar system. Under strong degree of aberration, the spatial confinement is significantly degraded. However for SA, the degradation of the spatial confinement can be reduced by tuning the truncation of the transmit beam, which results from the novel finding in this work, namely, that the optimum truncation ratio depends on the degree of SA.

Information about the polarization of light is valuable because it contains information about the light source illuminating an object, the illumination angle, and the object material. However, polarization information strongly depends on the direction of the light source, and it is difficult to use a polarization image with various recognition algorithms outdoors because the angle of the sun varies. We propose an image enhancement method for utilizing polarization information in many such situations where the light source is not fixed. We take two approaches to overcome this problem. First, we compute an image that is the combination of a polarization image and the corresponding brightness image. Because of the angle of the light source, the polarization contains no information about some scenes. Therefore, it is difficult to use only polarization information in any scene for applications such as object detection. However, if we use a combination of a polarization image and a brightness image, the brightness image can complement the lack of scene information. The second approach is finding features that depend less on the direction of the light source. We propose a method for extracting scene features based on a calculation of the reflection model including polarization effects. A polarization camera that has micro-polarizers on each pixel of the image sensor was built and used for capturing images. We discuss examples that demonstrate the improved visibility of objects by applying our proposed method to, e.g., the visibility of lane markers on wet roads.

Plenoptic cameras enable capture of directional light ray information, thus allowing applications such as digital refocusing, depth estimation, or multiband imaging. One of the most common plenoptic camera architectures contains a microlens array at the conventional image plane and a sensor at the back focal plane of the microlens array. We leverage the multiband imaging (MBI) function of this camera and develop a single-snapshot, single-sensor high color fidelity camera. Our camera is based on a plenoptic system with XYZ filters inserted in the pupil plane of the main lens. To achieve high color measurement precision of this system, we perform an end-to-end optimization of the system model that includes light source information, object information, optical system information, plenoptic image processing and color estimation processing. Optimized system characteristics are exploited to build an XYZ plenoptic colorimetric camera prototype that achieves high color measurement precision. We describe an application of our colorimetric camera to color shading evaluation of display and show that it achieves color accuracy of ΔE<0.01.

We present an overview of approaches to the design of nanometrology coordinates measuring setup with a focus on methodology of nanometrology interferometric techniques and associated problems. The design and development of a nanopositioning system with interferometric multiaxis monitoring and control involved for scanning probe microscopy techniques (primarily atomic force microscopy, AFM) for detection of the sample profile is presented. Coordinate position sensing allows upgrading the imaging microscope techniques up to quantified measuring. Especially imaging techniques in the micro- and nanoworld overcoming the barrier of resolution given by the wavelength of visible light are a suitable basis for design of measuring systems with the best resolution possible. The practical measurement results of active compensation system for positioning angle errors suppression are presented as well as the analysis of overall achievable parameters. The system is being developed in cooperation with the Czech metrology institute and it is intended to operate as a national nanometrology standard combining local probe microscopy techniques and sample position control with traceability to the primary standard of length.

The reliability of nanometer track writing in the large scale chip manufacturing process depends mainly on a precise positioning of the e-beam writer moving stage. The laser interferometers are usually employed to control this positioning, but their complicated optical scheme leads to an expensive instrument which increases the e-beam writer's manufacturing costs. We present a new design of an interferometric system useful in a currently developed cost effective e-beam writers. Our approach simplifies the optical scheme of known industrial interferometers and shifts the interference phase detection complexity from optical domain to the digital signal processing part. Besides the effective cost, the low number of optical components minimizes the total uncertainty of this measuring instrument. The scheme consists of a single wavelength DFB laser working at 1530 nm, one beam splitter, measuring and reference reflectors and one photo-detector at the interferometer output. The DFB laser is frequency modulated by slight changes of injection current while the interference intensity signal is processed synchronously. Our algorithm quantifies the phase as two sinusoidal waveforms with a phase offset equal to the quarter of the DFB laser wavelength. Besides the computation of these quadrature signals, the scale linearization techniques are used for an additional suppression of optical setup imperfections, noise and the residual amplitude modulation caused by the laser modulation. The stage position is calculated on basis of the DFB laser wavelength and the processed interference phase. To validate the precision and accuracy we have carried out a pilot experimental comparison with a reference interferometer over the 100 mm measurement range. The first tests promise only ±2 nm deviation between simplified and the reference interferometer.