Whats New in ZEMAX

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Whats New in ZEMAX?
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What Is ZEMAX?

• ZEMAX is a ray-tracing code used to model,
  optimize and tolerance almost any kind of optical
  system
• 15 year history, now the most widely used code in
  the industry
• Three core technologies
• Sequential ray-tracing for imaging systems
• Non-Sequential ray-tracing for illumination,
  stray light
• Physical Optics for laser and coherent beam
  propagation
• Three steps to our approach
• Analyze
• Optimize
• Tolerance

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Analyze Optimize Tolerance

• Analyze means simulating the performance of a
  current optical design
• Optimize means set targets for what you want to
  achieve, and have ZEMAX work with you to achieve
  your goals
• Tolerance means to assess the effect of
  manufacturing defects and other real-world
  effects than mean the real system behaves
  differently to the computer model.
• -can you actually build a system with this
  performance?

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Its Never Finished

• This talk reviews the recent major additions to
  ZEMAXs capabilities, in each technology area and
  within the analyze-optimize-tolerance cycle.
• ZEMAX is updated approximately bi-monthly, and
  user feedback is key to what goes in each update

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Imaging Systems

• Probably the most frequently-requested feature in
  imaging systems is to use afocal units when
  describing systems with afocal image spaces,
  without using an auxiliary paraxial lens

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Afocal Image Spaces

• This made a lot of people very happy!

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Analyze Optimize - Tolerance

• This makes one nice improvement to the user
  interface
• - the use of afocal units
• But actually it makes no difference to system
  performance, optimization, or tolerancing
• Prior use of a paraxial lens gave exactly the
  same results in all cases
• So, no significant changes in design capability,
  but a nice enhancement in terms of units used

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Ignore Surfaces

• Another requested feature was to temporarily turn
  off optical surfaces or components, especially
  when using multiple configurations
• This has been added via the user interface, MC
  editor, ZPL and Extensions
• Allows easy control of optical paths

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Conjugate Systems

• Here is a single system which can be thought of
  as a combination of two systems
• a focal imaging system
• an afocal relay
• In addition, you may also be interested in
  pupil-pupil imaging
• These can now be easily considered as conjugate
  sub-systems of the base design

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Make Conjugate Tool

• There is now a tool to allow you to define these
  sub-systems easily

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Optimizing Tolerancing Results

• The idea of optimizing a lens for reduced
  tolerance sensitivity is that a very low merit
  function is not useful if the as-built
  performance is significantly degraded by
  tolerance sensitivity. Therefore, the optimal
  design has a reasonable nominal performance but
  is relatively insensitive to manufacturing
  defects. The theory is there may be a potential
  trade-off between performance and tolerance
  sensitivity.
• Tolerance sensitivity in an optical design comes
  from many sources, including angles of incidence
  of rays on surfaces, aberration balancing, and
  the nature of the potential fabrication defects.
  The interaction of multiple defects makes
  accurate tolerance prediction a difficult
  statistical problem.

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TOLR

• The TOLR operand allows you to access
  manufacturing sensitivity directly in the merit
  function
• The practical difficulty of optimization of
  tolerance sensitivity lies in the computation
  time. Complicated lenses may have hundreds of
  tolerance operands, and complex criteria may take
  considerable time to compute.
• However TOLR can make a significant improvement
  in the initial design evaluation stage, and help
  to produce manufacturable lenses more easily

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Illumination Systems

• One of the biggest new features of 2005 for our
  illumination users was Sobol Sampling of
  non-sequential sources
• Sobol sampling is a neat idea to improve upon
  random sampling of source output
• Truly random values are not always desirable. The
  reason is that random numbers tend to not
  uniformly sample parameter space if the number of
  samples is small.
• Random numbers may group together, leaving
  relatively large gaps in sampling space.
• In practice, this means that it takes a great
  many rays to get sufficient sampling to produce
  smoothly varying results.
• A solution is to use a sampling method which
  looks qualitatively random, but is in fact a
  carefully selected distribution that optimally
  "fills in" previously unsampled space.

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Sobol Sampling

• Sobol sampling is less clumpy than true random
  rays

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Sobol Sampling

• Better signal/noise for the same number of rays

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Simple Ray Splitting

• ZEMAX can compute reflection and transmission at
  the surfaces of objects, and launch a new ray to
  take away the reflected energy. This is essential
  for stray light, and important in many
  illumination systems

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Simple Ray Splitting

• Simple splitting isnt really splitting at all,
  but rather a probabilistic approach that EITHER
  reflects OR transmits a ray, based on the T/R
  coefficients
• mainly useful in illumination systems

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Simple Splitting

• Useful for illumination systems, like this
  brightness enhancement filter

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Complex Geometry Creation

• Currently in beta, we now have the capability to
  perform Boolean operations on components
• This is a simple lens mount, formed by
  subtracting several cylinders from a rectangular
  volume

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Boolean Objects

• Another simple example two overlapping spheres

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Surface Finishes

• Different surface finishes can be applied to any
  face of any object, like this Newport lens mount

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Boolean Objects

• Currently up to 10 objects can be combined in a
  single operation
• The resulting object traces to optical accuracy,
  and retains any surface finishes or diffractive
  properties inherited from its parents
• Provides a simple CAD-like capability directly
  inside the optical program
• Resulting object is parametric, therefore can be
  optimized and toleranced easily.

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Physical Optics

• Physical Optics Propagation (POP) allows a
  coherent beam to propagte though any optical
  system at any angle, from any field position
• ZEMAX now supports Hermite-Gaussian beams of any
  order, such as this TEM3,4 mode

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Multiple Modes

• ZEMAX also allows multi-mode files to be created
  by the coherent or incoherent addition of other
  modes, like this donut mode

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M2

• M2 is a quality number that defines how closely
  to a Gaussian a beam diffracts
• Computed as the second moment of the complex
  amplitude distribution
• Useful to diagnose beam quality, as when we
  change the length of the collimated region in
  this fiber coupler

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Fiber Coupler
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Other Changes

• Many, many other improvements
• ZEMAX can now use up to 8 CPUs per machine, for
  serious number crunching
• The multi-threaded architecture is just begging
  for the latest multi-core CPU machines!
• Many new Tools added to give extra convenience
• Follow-chief-ray, surface tilts/decenters,
  decentering elements
• System Check utility checks for common setup
  errors

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Knowledge Base

• We also have a new online Knowledge Base at
  www.zemax.com/kb
• Many How-To, Tutorial articles, plus answers to
  frequently asked questions

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Summary

• Many new features added in 2005, and 2006 is
  going to be no different
• We continue to focus on the needs and requests of
  our large user base to guide us in the
  development of ZEMAX.