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Programm OptoNet Seminar ›Beleuchtungsoptik‹

Optics basics (ray optics)

  • Spectrum / wavelength
  • What is a ray?
  • Refraction / reflection

Radiometric/photometric quantities, incl. motivation and measurement

  • Radiometric vs. photometric
  • Radiant flux / luminous flux
  • Irradiance / illuminance
  • Radiant intensity / luminous intensity
  • Radiance / luminance

Phase space definition (as simple as possible but no simpler)

  • Screens
  • A ray = four numbers = a point with four coordinates
  • Snell’s law revisited
  • Phase space definition
  • Etendue definition
  • Skewness

Photometric quantities in phase space

  • „Luminance is the density of flux in phase space“
  • Illuminance as weighted integral of luminance over solid angle
  • Intensity as weighted integral of luminance over area
  • Flux as 4D-integral of luminance over etendue
  • The “play dough analogy” and the “whipping cream analogy”

Light sources and how to model them

  • Lambertian sources
  • LEDs
  • Traditional: Incandescent, fluorescent, HID
  • Physical / heuristic source models (spatial and angular apodization, volume)
  • Ray files

Simulation of illumination optics systems

  • Ray tracing and the curse of Monte Carlo noise
  • Modeling object properties, and how that interacts with ray tracing
  • Source-optics-receiver
  • Measuring etendue with ray tracing software

Design elements

  • Lenses
  • TIR lenses, and why the cannot be perfect collimators
  • Reflectors with and without facets, and what they do to etendue
  • Collimators: Simple lens/reflectors, CPCs, cones
  • Homogenizers: Etendue-conserving (Mixing rods, Fly's Eye condensers (double sided micro lens arrays), Etendue increasing (Single sided micro lens arrays, Diffuser plates)
  • Dichroic filters

Colorimetry and color mixing

  • Human color perception
  • CIE color spaces, with critique
  • Machine/camera color perception
  • Color rendering, CRI, CQS, TLCI, …
  • Color mixing with LEDs Intuitive geometrical concept (Color mixing = vector addition in 3D X-Y-Z tristimulus space), LED binning and how it influences color, LED operating conditions and how they influence color
  • Color mixing optics (Homogenizers revisited)
  • How can we quantify and measure homogeneity?

Design methods / archetypal design approaches

  • Corralling the problem using the Physics fence, and understanding the problem from a bird’s eye view

    • Light has quantity AND quality
    • Sufficient flux?
    • Sufficient luminance?
    • Does symmetry help us, or kill us? (Etendue squeezing / symmetry breaking)

  • When source etendue is small:

    • Point source method, possibly with scattering
    • Simple optics (lenses, paraboloidal/elliptical reflectors)
    • State of the art: Free form surfaces / Tailoring.

  • When source etendue is too large:

    • When full efficiency is important: STOP!
    • Otherwise: Understand and apply the luminance – etendue characteristic curve
    • Then continue as if „source etendue just right”

  • When source etendue is just right:

    • Often, very challenging problems
    • Understand edge rays
    • Build solution using etendue conserving elements

  • Optimization
  • How can we use ray tracing to understand the flow of light in a system?

Archetypal design problems

  • Downlight, soft spot lights – a whole zoo of optical design options
  • Wall washing – with and without freeform optics
  • Hard edge spot lights – baffle projection vs. fly’s eye condensers
  • Multi color Köhler Illumination
  • “Live” problems from the audience

März 2019

Dienstag
12
März
Dienstag
26
März

Mai 2019

Dienstag
14
Mai

November 2019

Montag
18
November