- Front Matter: Volume 8720
- Fiber Optic Sensors Systems
- Imaging Sensors
- See-through Wearable Displays/Vision-based Sensors
- Photonics in Aviation and Commercial Industries
- Optical Sensors and Interconnect for Harsh Environment
- Speciality Sensors/Communication Networking
- Speciality Fiber Development and Application of Optical Polymer
- Monitoring and Spectrum Systems/POF Systems
- Communication Systems and Components
- Optical Systems, Sources, and Components
- Poster Session
Recent development in High Power LED (HPL) is poised to replace traditional lighting sources such as Fluorescent, HID, Halogen and conventional incandescent bulbs in many applications. Due to the solid state compact nature of the light source it is inherently rugged and reliable and has been the favored lighting source for most indoor and outdoor applications including many hazardous locations that impact, and safety environments including mining, bridge, aerospace, and automotive . In order to accelerate this transition many enhancements and advances are taking place to improve on the reliability, and thermal performance of these devices.
With the use of large LED arrays, it is possible to generate large heat loads at the system level which can cause challenges for overall heat dissipation, especially when cooling requirements call for passive methods. These two challenges work together to cause elevated LED die temperatures, which have been linked to lower quantum efficiencies, shorter lifetimes, emission wavelength shifts and catastrophic device failure. It has been predicted previously that the lifetime of a device decays exponentially as the temperature increases. This can result in a lifetime decrease from 42,000 hours to 18,000 hours when the device temperature increases from 40°C to 50°C.
This paper explores the various improvements and advances made in the micro-packaging of LEDs to enhance their performance.
The combination of fossil fuels with bio-fuels, specially ethanol and methanol, has acquired relevance and attention in several countries in recent years. A variety of factors have induced this trend: market prices, constant geopolitical events, new sustainability policies and laws, etc. The fuels used in the automotive industry, including bio-fuels, normally contain additives as anti-shock agents and as octane booster. These additives may endanger (beside the high volatility implied) public health or environment due to the nature of its chemical composition.
Raman spectral information from different additives, specially toluene, contained in E10 gasoline-ethanol blends has been obtained by using an own-design Fourier-Transform Raman spectrometer (FT-Raman). This information has been also compared with Raman spectra from pure additives and with standard Raman lines in order to validate its accuracy in frequency. The spectral information is presented in the range of 0 cm−1 to 3500 cm−1 with a resolution of 1.66 cm−1. The Raman spectra obtained shows a reduced frequency deviation (less than 0.4 cm−1 when compared to standard Raman spectra from different calibration materials, e.g. cyclohexane and toluene, without compensation for instrumental response).
The Fourier-Transform Raman spectrometer prototype used for the spectral analysis, consisting of a Michelson interferometer and a self-designed photon counter cooled down on a three stage Peltier element arrangement, is able to extract high resolution and precise Raman spectra from the additives in the fuels analyzed. The proposed FT-Raman prototype has no additional complex hardware or software control. The mechanical and thermal disturbances affecting the FT-Raman system are mathematically compensated by extracting the optical path information from the generated interference pattern of λ = 632.8nm Helium-Neon laser (HeNe laser), which is used at the spectrum evaluation. This allows the device to be used in complicated environments where certain level of security is required (e.g. fuel production, storage, transportation, etc.).
A fiber optic system can be designed, assembled and installed with many options for active and passive components and system elements. Interconnection systems should be designed with a detailed BOM, including fiber/cable, connectors, ruggedization materials and other passive components for the desired application. The selection of these items should be specific to the requirements of the system when considering environmental and mechanical limitations, and from the standpoint of the users who will be installing, maintaining and possibly repairing the system sometime in the future. Proper installation, maintenance and repair training is essential.
The paper will review various up-to-date alternatives, particularly for mil-aero applications, available when selecting components at design-in stage and discussing options for different scenarios of required optical performance. Considerations of component selection with regard to capabilities of the installers, maintenance and repair personnel and other key people who will be responsible for the success of the system will also be discussed.
Training resources will be discussed. A fiber optic system when compared to an electrical system is not necessarily more difficult to install and maintain, but training for key different issues is a must. With appropriate component selection at the design stage and adequate training of installers/handlers is completed, the fiber optic system will be successful.
Achieving affordable high speed fiber optic communication networks for airplane systems has proved to be challenging. In this paper we describe a summary of the EU Framework 7 project DAPHNE (Developing Aircraft Photonic Networks).
DAPHNE aimed to exploit photonic technology from terrestrial communications networks, and then develop and optimize aircraft photonic networks to take advantage of the potential cost savings. The main areas of emphasis were on: multiplexing networks; providing standard components; simplifying installation; and reducing through life support costs. DAPHNE (fifteen partners from seven nations) finished in February 2013; and was supported by the European Commission‟s Seventh Framework Programme, although the consortium members are continuing with in-house developments.
Plastic Optical Fiber (POF) technology is utilized for wide variety of applications for its easiness of handling and robustness against environmental variation. Thanks to its large core diameter (typically 1mm) and large numerical aperture (typically 0.5) which provides wider acceptance angle, dimensional tolerance of POF can be extremely large. This is the reason why the simple and low cost connection technology can be used with POF.
Among these existing applications, the POF manufactures are primarily focusing on growing automotive and industrial data-com areas. Industrial data-com applications include field-bus system in plant area, power application (power station, sub-station) and locomotive control systems. Automotive data-com with POF is used for In-vehicle networks for infotainment systems or safety information bus.
For these applications, POF is required to be durable against harsh environment such as high temperature (~105C), dynamic mechanical movement for robotic arms and compatibility with machine oil or other chemical substances. To satisfy these application specific requirements, the structure and material of POF and its jacketing are optimally designed. Through these development activities, POF technology evolved into well adopted industrial standard. As an extension of this evolution, aero space application is another great possibility to challenge for POF industry.
The present paper reports the latest technology and the features of those jacketed POF used in these applications, and describe about future possibility for aerospace applications.
This paper will focus on the trends for the space-based lasers, optics and terminals used in the intersatellite networks. Reviewed and evaluate the recent development in the space-based laser technologies and the critical parameters that are employed for successful high-speed inter-satellite communications systems.
Building laser for high speed communications network for the harsh environment of space using optical links in space has proven to be complicated task and many such schemes were tried without success in the past. Space-based optical communications using satellites in low earth orbit (LEO) and Geo-synchronous orbits (GEO) hold great promise for the proposed Internet in the Sky network of the future. However in the last few years, there has been impressive progress made to bring the concept of laser-based intersatellite systems to fruition in civilian and government-non classified projects. Laser communications offer a viable alternative to established RF communications for inter-satellite links and other applications where high performance links are a necessity. High data rate, small antenna size, narrow beam divergence, and a narrow field of view are characteristics of laser-based systems and they are just few numbers of potential advantages for system design over radio frequency communication.
QD Vision has developed Quantum Dot Light Emitting Devices whose emission spans the wavelength range from 1000 nm to 1.35 μm, using tunable, narrow band quantum dot emission. These devices emit sufficient power for long range-detection by a variety of systems, run at very low drive voltages, and are producible in area emitting form-factors that are very thin and light weight. Potential applications for these devices include covert illumination, tagging, display backlighting, and line-of-sight communications.
In this paper, we demonstrate electrically driven quantum dot light emitting devices that emit in the wavelength range of 1000 nm to 1.35 μm, with full-widths at half-maximum as low as 128 nm. The devices discussed are characterized with respect to their efficiency, power output, and lifetime, and this data is used to evaluate their suitability for use in a variety of defense-related applications. Example devices are discussed, including completed prototypes 1.5mm thick with active areas up to 4 cm2. Experimental results are presented that demonstrate a low turn-on voltage of 1.4 V, a maximum external quantum efficiency of 2.5 %, a power efficiency of 25 mW/W, and a peak radiance of 18.3 W/sr.m2. Lifetimes of more than 1000 hours at operating drive levels are also shown.
The purpose of this effort is to apply an in-situ corrosion remote sensing capability in aircraft structural environments. The technique will permit detection of corrosion on and within aircraft structures and component junctions that are susceptible to corrosion, but which are not accessible for visual inspection. The field application configuration includes surface and embedded optical fiber probes interfaced with a Fourier Transform Infrared (FTIR) interferometer for evanescent wave absorption spectroscopic measurements. The mature and fielded technique will allow periodic remote sensing for structural health monitoring and detection of corrosion.
The potential advantages of optical fiber sensors result from the fact that the sensing element, the optical fiber, is small size, light weight, and immune to electromagnetic field. Also it can be attached to surfaces or embedded in junctions in aircraft structures, in locations where humidity and corrosion can accumulate, but cannot be directly observed.