ADVANTAGES OF USING OFF-THE-SHELF OPTICS IN YOUR … · •Next day versus months for spherical components •Optics production takes a lot of time –Glass lead times –Time to

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


ADVANTAGES OF OTS OPTICS

Cost

• Prototyping and Low volume while taking advantage of large lot sizes

• Economy of Scale

– Set up costs

– Lot sizes



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



For Production and Large volumes there are further advantages

• Logistics

• Blanket orders

• Less investment in inventory

• Flexibility


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


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


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


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.


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


USING COMPONENTS

• Understand how OTS components are designed

– Conjugates and shape factors

– Wavebands

– Field


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


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


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


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


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


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?


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


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”


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


THANK YOU

21

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ADVANTAGES OF USING OFF-THE-SHELF OPTICS IN YOUR … · •Next day versus months for spherical components •Optics production takes a lot of time –Glass lead times –Time to