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Thermographic Imaging Selecting an IR Camera with the Right Detector

The thermographic imaging characteristics of an IR camera are largely determined by its detector assembly. Infrared radiation (IR) is focused onto the camera’s detector assembly, which is a focal plane array (FPA) that converts IR into a visual image depicting temperature variations across the camera’s field of view (FOV). The FPA consists of thousands of pixels, which could be fabricated from any one of the IR sensitive materials commonly used in these cameras. Most detector materials respond to a selected portion of the IR spectrum (Figure 1). Therefore, a camera selected for any given application should have the appropriate FPA material based on the IR characteristics of objects within the FOV and the user’s study objectives.

Posted in: Articles, Features, ptb catchall, Photonics

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Compact 6-DOF Stage for Optical Adjustments

Adjustments can be made in all translational and rotational degrees of freedom. NASA’s Jet Propulsion Laboratory, Pasadena, California The figure depicts selected aspects of a six-degree-of-freedom (6-DOF) stage for mechanical adjustment of an optical component. The six degrees of freedom are translations along the Cartesian axes (x, y, and z) and rotations about these axes (θx, θy, and θz, respectively). Relative to prior such stages, this stage offers advantages of compactness, stability, and robustness, plus other advantages as described below.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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Fiber Optic Communications Systems

Communications and, more recently telecommunications, are needs deeply engrained in human history. These needs have significantly evolved over time enabling today’s content-rich (text, music, images and video, etc), real-time and multi-location exchanges through electrical, optical or, more broadly, electromagnetic signals conveyed by different media. Among the more versatile is optical fiber.

Posted in: Articles, Features, ptb catchall, Photonics

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Designing Converged Optical Ethernet Networks

Transport networks have witnessed two significant trends over the past half-decade or so. The first has been an explosion in the bandwidth these networks can support and the distances over which they can support it. This is due to the advent of cost-effective wavelength division multiplexing (WDM) and dense-WDM (DWDM), as well as a slew of technologies that extend transmission range, such as sophisticated optical amplifiers. The second has been the need to support a variety of traffic types (voice, video, data) and services: virtual private networks (VPNs), high-speed Internet (HSI), video-on-demand (VoD) and videoconferencing, and IPTV, to name a few. This is due to the need to simplify the network by collapsing intermediate layers and protocol stacks, thus reducing interface and node counts (and, hence, cost) in the carrier network. Thus, transport networks have migrated from being primarily voice-dominated to multi-service supporting infrastructures.

Posted in: Application Briefs, Applications, ptb catchall, Photonics

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Compact Two-Dimensional Spectrometer Optics

This unit would feature coarse and fine resolution along two orthogonal axes. NASA’s Jet Propulsion Laboratory, Pasadena, California The figure is a simplified depiction of a proposed spectrometer optical unit that would be suitable for incorporation into a remote-sensing instrumentation system. Relative to prior spectrometer optical assemblies, this unit would be compact and simple, largely by virtue of its predominantly two-dimensional character.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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Graphite/Cyanate Ester Face Sheets for Adaptive Optics

Unlike glass face sheets, these would be nearly unbreakable. Marshall Space Flight Center, Alabama It has been proposed that thin face sheets of wide-aperture deformable mirrors in adaptive-optics systems be made from a composite material consisting of cyanate ester filled with graphite. This composite material appears to offer an attractive alternative to low-thermal-expansion glasses that are used in some conventional optics and have been considered for adaptive-optics face sheets.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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Fractal-Based Encryption

Encryption methods based upon nonprobabilistic nondeterminism show promise in the optical age. In 1987 a discovery led to the formal proof that it is possible to use chaotic functions to arrive at a nonprobabilistic and nondeterministic method normal context of the operation of this system, and by using a virtual operational environment, the investigators are manipulating data in eight dimensions, which require a sixty-four discrete coordinate system, using eight nominative octets. Each octet is further addressed using the characters 0 through 9, and lower- or upper-case letters from A to Z. These provide the ability to address using normal ASCII characters. This format was chosen to ensure backward and forward compatibility with external third-party-written software.

Posted in: Photonics, Briefs, ptb catchall, Tech Briefs, Photonics

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