KEYWORDS: Light emitting diodes, Light sources and illumination, Solid state lighting, Spherical lenses, Near field optics, Sensors, Optical testing, General lighting, Cadmium, Calibration
The photometric modeling of LEDs as generalized Lambertian sources (GL-Sources) is discussed. Non-Lambertian
LED sources, with axial symmetry, have important real-world applications in general lighting. In particular, so-called
generalized Lambertian sources, following a cosine to the nth power distribution (n≥1), can be used to describe the
luminous output profiles from solid-state lighting devices like LEDs. For such sources, the knowledge of total power (in
Lumens [Lms]), the knowledge of the output angular characteristics, as well as source area, is sufficient information to
determine all other critical photometric quantities such as: maximum radiant intensity (in Candelas [Cd = Lm/Sr]) and
maximum luminance (in nits [nts = Cd/m2]), as well as illuminance (in lux [lx = Lm/m2]). In this paper, we analyze this
approach to modeling LEDs in terms of its applicability to real sources.
In this paper, biologically-inspired optical imaging systems, including fish eye, bug eye, lobster eye, and RGB color
vision, are discussed as new lensing systems for military and homeland security applications. This new area of interest
includes UV, VIS, IR, and X-ray part of electromagnetic spectrum. In particular, recent progress at Physical Optics
Corporation will be discussed, including such applications as hyperspectral/multi-spectral imagery, video surveillance,
and X-ray inspection.
KEYWORDS: Homeland security, Modeling and simulation, Prototyping, 3D modeling, Systems modeling, System integration, Microwave radiation, Systems engineering, X-ray optics, Manufacturing
A highly productive approach to small systems design and integration (SSDI), and modeling and simulation (M&S),
based on rapid/interactive prototyping has been effectively used at Physical Optics Corporation (POC) to support small
system development of "intellectual products" that cover a broad range of electromagnetic spectra (X-ray, optical,
infrared, and microwave). In particular, the implementation of an accelerated interactive modeling (AIM) environment
produces effective engineering solutions for tackling difficult and complex technical issues for combining 3D
mechanical design and microwave engineering. In addition, using established small systems engineering principles and
the effective use of collaborative input at the start of a development effort that incorporates a diverse range of areas like
optics, mechanics, electronics, software, thermal modeling, electromagnetism, surface chemistry, and manufacturing
plays an important role in the success of future military and homeland security applications.
In this paper, the foundations of radiometry and photometry, based on Second Principle of Thermodynamics are
discussed, in terms of brightness (luminance), and etendue (Lagrange invariant) limitations of integrated lighting
systems. In such a case, the brightness is defined as phase-space-density, and other radiometric/photometric quantities
such as emittance, exitance, or irradiance/illuminance, power/flux, and radiant/luminant intensity, are also discussed,
including examples of integrated lighting systems. Also, technologic progress at Luminit is reviewed, including 3D-microreplication
of new non-diffuser microscopic structures by roll-to-roll web technology.
In this paper, integrated lighting is discussed, including light sources, rough or relief surfaces such as diffusers and microprisms, as well as theoretical limits of ray tracing and photometry, and performance metrics of integrated lighting systems.
Most state-of-the-art commercial, industrial, and military display technologies require some type of backlight illumination. Optimization of such lighting systems with respect to brightness, uniformity, and viewing angle is critical to achieving technical specifications and overall performance of display applications. Considering the substantial cost and risk factors involved in developing advanced displays it becomes important to utilize superior design tools that accurately model the radiometric performance of illumination systems including the behavior of all optical components (quasi-homogeneous sources, optical films, micro-prisms, etc.). To this end, Physical Optics Corporation (POC) has been successfully using an internally developed design platform called R2T to perform radiometric ray tracing (R2T) of backlights and general lighting applications that incorporate non-Lambertian (elliptic) diffusers and other weakly diffracting optical components. For years POC has been involved in the design of illumination systems for advanced displays including manufacturing expertise in large size web replication of optical films and injection molding of microstructures for display technology.
Global computer modeling of display systems, based on Radiometric RayTracing (R2T), has been proposed, for determining radiometric (photometric) quantities in phase-space, including radiance (luminance) which represents phase-space density. Verification with experiment is also discussed.
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