ADVANTAGES OF USING OFF-THE-SHELF OPTICS IN YOUR … · •Next day versus months for spherical...
Transcript of ADVANTAGES OF USING OFF-THE-SHELF OPTICS IN YOUR … · •Next day versus months for spherical...
ADVANTAGES OF USING OFF-THE-SHELF
OPTICS IN YOUR APPLICATIONS
Jeremy Govier
Principal Engineer
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
OFF THE SHELF(OTS) OPTICS
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
ADVANTAGES OF OTS OPTICS
Cost
• Prototyping and Low volume while taking advantage of large lot sizes
• Economy of Scale
– Set up costs
– Lot sizes
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
ADVANTAGES OF OTS OPTICS
Speed
• Next day versus months for spherical components
• Optics production takes a lot of time
– Glass lead times
– Time to process
• Lens production is a many step process
– Raw glass
– Blank generation/molding
– Grinding
– Polishing
– Centering
– Coating
• Assembly adds even more time
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ADVANTAGES OF OTS OPTICS
For Production and Large volumes there are further advantages
• Logistics
• Blanket orders
• Less investment in inventory
• Flexibility
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DISADVANTAGES OF OTS OPTICS
Less degrees of freedom
• Finite number of shape factors available
• Finite number of focal lengths available
• Finite number of sizes available
Less control
• Tolerances
• Specifications outside the defined areas
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TYPES OF OTS OPTICS
Co
mp
on
en
t • Singlets
• Doublets
• Mirrors
• Windows
• Prisms
• Filters
Su
ba
sse
mbly • Objectives
• Eyepieces
• Relays
• Photographic Lenses
• Machine Vision Lenses
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CUSTOMIZING STOCK COMPONENTS
• Edge Downs/profile changes
• Custom coatings
• Tighter tolerance
– Measuring actual parts
– Finishing to achieve tighter surface
• Using a OTS as a blank or semi-finished part to make a custom
surface
– Polishing an asphere onto an existing sphere
– Small radius changes
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CUSTOMIZING STOCK ASSEMBLIES
• Customizing the housing is simpler and cheaper than customizing
lenses
• Can eliminate costly and time consuming development of the
assembly
• Ruggedizing an assembly for harsh environments
– Vibration
– Sealing
• Eliminating parts that are not necessary
– Removing adjustability like focus movements, iris adjustments
• Add coatings for specific wavebands.
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DESIGN TIPS FOR SUCCESSFULLY
USING OTS IN YOUR APPLICATIONS
• Components
– How to best use components within your design
• Subassemblies
– How to use a subassembly to replace custom design
• Hybrid
– How to mix in a subassembly to a larger system in conjunction
with optical elements
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
USING COMPONENTS
• Understand how OTS components are designed
– Conjugates and shape factors
– Wavebands
– Field
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
CONJUGATES
• Since the majority of OTS optical components are designed for
infinite conjugate on one side and finite conjugate on the other, set up
your systems to take advantage of this.
• Break finite conjugate systems into combinations of infinite conjugate
subsystems
• If you need a non-equi bi lens, try splitting into two plano elements
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WAVEBAND
• Color correction requires significant degrees of freedom
• Reducing waveband through illumination or filtering can greatly
reduce complexity and improve performance
• When broadband is needed use components designed for the
waveband you are needing
• Broadband performance often requires subassemblies instead of
component
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FIELD
• Components by themselves do not have any correction for field
aberrations
• Using stop placement and balancing Petzval powers can help reduce
your field aberration
• Keeping field angles small will greatly help performance
– Lengths total track
• If large field angles are needed look to subassemblies or hybrid
solutions
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GENERAL ADVICE ON DESIGNING WITH
OTS OPTICAL COMPONENTS
• Minimize, determine what you need and start only with that
• Start paraxial
• Fit components to your paraxial model
• Be flexible with size, you can edge down later if necessary
• Add complexity as needed
• If you get stuck, consider using subassemblies
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
USING SUBASSEMBLIES
• Conjugates
– Photographic lenses, microscope objectives, and eyepieces are
typically optimized for infinite conjugates
– Machine vision lenses are optimized for a wide variety of finite
conjugate ratios
• Wavebands
– Many options for broadband solutions over a wide variety of
wavebands
– Coatings and color correction
• Fields
– Optimized and corrected over specific field sizes
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
DESIGNING WITH SUBASSEMBLIES
• Start by finding a OTS solution that meets the basic optical
requirements of Waveband, Field of View, Magnification, and Total
Track
• Evaluate if it meets other requirement
• See if modifying housings and coatings can fulfil other requirements
• Are there unnecessary features such as focus adjustment, zoom, or
aperture adjustment that can be fixed?
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HYBRID SOLUTIONS
• Use a subassembly with components to make a system solution
• Use components to adjust focal length of a subassembly
• Replace a component you would use in a finite-infinite-finite with a
subassembly like a microscope objective or photographic lens
• Use different achromats to adjust the magnification of an infinite
conjugate microscope objective
PROPRIETARY - Property of Edmund Optics, Inc. | 2016 Copyright© Edmund Optics, Inc.
USING OTS COMPONENTS IN A
EXISTING DESIGN
• Look for shape factors similar to your existing design
• Find focal lengths of elements and try to replace with similar focal
length stock lenses
• Flip lenses as appropriate to get the conjugates matched up
appropriately
• Replace one lens at a time re-optimize in-between
• Make custom lens catalogs if you try to optimize multiple lenses at
once or if you need to constrain choices more than the code allows
you
• Zemax/Optics Studio has a new optimizer “Stock Lens Matching”
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CATALOG LENS MATCHING
• Word of caution
– It will only match like
lens types, such as
plano to plano, equi to
equi, etc
– You will want to force
meniscus singlets to
either plano or equi
before running it
– Doublets do not have
this issue
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THANK YOU
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