1. Design and Performance of a New Reflecting Microscope for FT-IR Microspectroscopy

2. Infinity Corrected Microscope Optics
Finite Tube Length
Objective
Tele Lens
Specimen
Eyepiece
Accessory Optics

3. Infinity Corrected IR Microscopes
InspectIR was first example - US Patent 5,581,085
Better Image Quality
Schwarzschild theory based on infinite conjugate
Better IR performance
Flat mirror relay optics - simplicity, alignment
Ease in introducing optical modules
future upgrades
Intermediate optical surfaces not focussed

4. Continumm IR Ray Diagram - Transmission
Source input
Specimen
Detector output
Reflextm aperture
Dichroic Mirror
Infinity Corrected
Objective
Condenser

5. Continumm IR Ray Diagram - Reflection
Detector output
Reflextm aperture
Source input
Dichroic Mirror
Infinity Corrected
Objective
Specimen
Split Mirror

6. Continumm IR Optical Design
Single ReflexTM aperture
Infinity corrected reflecting objectives, condensers
Dichroic mirrors (3) for simultaneous viewing (TruViewTM), IR data collection, and aperture illumination (TruViewTM)
Dual detector capability
Correction for focal shift, spherical aberration

7. Continumm IR Optical Design ReflexTM Aperturing
Single aperture, dual pass
Patent pending
Ease-of-use
Unsurpassed FT-IR microscopy performance
S/N, spatial resolution, photometric accuracy
Performance equivalent to dual aperturing systems
US Patent 4,877,960

8. Signal-to-Noise and Detector Response Performance
%Transmittance
2450
2500
2550
2600
Wavenumbers (cm-1)
0.01%T
Narrow-band
Mid-band
Wide-band %T
500
600
700
800
900
1000
1100
1200
Wavenumbers (cm-1)
Narrow-band
Mid-band
Wide-band
Baseline Noise
Caffiene Spectra

9. Photometric Accuracy Imide bands <4 %T5 10 15 20 25 30 35 40 45 50
%Transmittance
1000
1500
2000
2500
3000
3500
4000
Wavenumbers (cm-1)
Imide bands <4 %T
12 mm diameter KevlarTM Single Fiber Spectrum

10. IR Spatial Resolution Polymer Laminate - 10 mm layer illuminated

11. IR Spatial Resolution Laminate Spectra %T Wavenumbers (cm-1) 60 70 2040 80
1000
1500
2000
2500
3000
3500
4000
Wavenumbers (cm-1)
30 mm Layer - polyvinyl chloride
10 mm Layer - polyvinylidene fluoride (plasticized)
Large Layer - polyvinylidene fluoride

12. Dichroic Reflectivity
vs. Au degrees incidence 86 88 90 92 94 96 98
100
102
104
%Reflectance
1000
2000
3000
4000
5000
Wavenumbers (cm-1) A B C
A. s-polarization
B. random polarization
C. p-polarization

13. System Polarization Efficiency
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
I (perpindicular) / I (parallel)
1000
1500
2000
2500
3000
3500
4000
Wavenumbers (cm-1) %

14. Koehler Illumination Illuminator Filament Focussing Lens Aperture Iris
Field Iris
Filament Image
Field Iris Image
Cassegrain Secondary
Specimen

15. Koehler Illumination
NIC / ST provides the only true Koehler illumination system for FT-IR Microscopes
transmission & reflection
Field stop (iris) imaged at specimen
uniform illumination intensity
Adjustable aperture iris
contrast control (illumination intensity reduced)
Adjustable field iris
only in focus when specimen plane is focussed, helps finding a low contrast specimen plane

16. Visible Illumination Ray Diagram
Reflection Koehler Illuminator
Transmission/Reflection
IR Beam Input
Flat Mirror
Viewer
Dichroic Mirror
Transmission Koehler
Illuminator
Transmission IR
Beam Output
Cassegrain Objective
Cassegrain Condenser
Specimen
Flat Mirror

17. Aperture Illumination Transmission
Viewer
ReflexTM Aperture
Flat Mirror
Dichroic Mirror
Cassegrain Objective
Cassegrain Condenser
Specimen
Aperture Illuminator
Filament
IR Detector Output

18. Optical Microscope Design Features
Infinity corrected
High intensity illuminators (3) for transmission, reflection, and aperture illumination
High visible transmission dichroics
simultaneous view/IR, aperture illumination (Tru ViewTM)
Olympus research grade viewers, 4-place nosepiece, infinity corrected refracting objectives
Koehler illumination
Optional ReflachromatTM IR objectives for diffraction-limited performance
Optional Polarized Light Microscopy
Optional Differential Interference Contrast (DIC)
Research grade optical microscopy

19. Image Quality 1951 USAF Resolution Test Target 15X Reflachromat
Smallest Bar Separation- 4.4 mm : Optical Resolution better than 1 mm

20. Spherical Aberration (Variation of Focus with Aperture)
Paraxial Focus
Optical Axis
Window substrate causes extreme rays to focus before rays near the optical axis

21. Image Quality - Compensation for Spherical Aberration
1951 USAF Resolution Target with 2mm BaF2 Cover Window
15X Reflachromat Objective
15X Reflachromat Objective
Compensated
Focused, Not Compensated

22. Differential Interference Contrast
Analyzer
Wollaston Prism
Objective
Specimen
Condenser
Polarizer

23. Differential Interference Contrast
First polarizer splits light into two polarized rays
Enhancement of separation by first Wollaston prism
Shadowing effect evident when 2 polarized beams pass through sample
Beams recombined by second Wollaston prism and polarizer
Crossed polarizers eliminate all light not altered by sample - shadow is all that passes .

24. Best possible phase contrast Non-DIC
100 mm
Human epithelial cell

25. Black and white DIC contrast
100 mm
Human epithelial cell

26. Pale Blue DIC Image
100 mm
Human epithelial cell

27. Differential Interference Contrast
First use of reflecting optics for DIC
Patent Pending
Aperture under DIC observation
Lockout Specification
Previously implemented using refracting optics - optical microscopes
Requires infinity corrected optical path
Applications - Biological, Biomedical, Mineralogical, Polymeric, Semiconductor, Materials Science

28. Continumm Electronics

29. Electronics Description
Virtually all microscope functions can be automated
FULL upgradeability from basic system to complete automation
All components fully integrated

30. Modes of Operation Transmission/reflection switching
Front panel control for viewing ease
Software control for data collection
Detector switching
Controlled by OMNIC

31. Illumination Intensity Controls
Field illuminators for transmission and reflection modes of operation
Reflex aperture illumination to simplify sample definition and masking
Variable intensity controls to maximize usage of aperture and field irises as well as color filters, polarizers, etc.

32. Motorized Aperture
Single aperture is used for pre- and post sample masking
Two speed motor assisted drive mechanism for precise movement
Transparent and always centered
Single adjust for each axis (x,y, ) of movement
Auto-aperture control in Atls
Draw desired aperture size and orientation with mouse
Software input of desired aperture settings is also available

33. Motorized Stage Control unit is now internal to microscope
Precision stepping to better than 1 micron
Joystick control of stage
Point and click sample positioning
Mosaic assembly for large samples
Spectral mapping (Transmission, Reflection, ATR)

34. Motorized Focus Precision 2-speed focus control
Z-focus limit switch to protect condensers
Manual focus control in Atls software
Autofocus control from Atls
Uses visual contrast to focus on sample image
Mapping (ATR, Trans., Refl.)

35. Contact Alert Pressure sensing plate for ATR spectroscopy
Front panel LED display showing when contact is optimal
Control unit is internal
Feedback for ATR mapping
Quantitative results better than 1% are achievable with ATR