UV Metrology & MicroscopySpatial FilteringPhotomicroscopyLaser Energy Delivery Sys-temsFT-IR Spectroscopy

Thermo Oriel's reflecting microscope objec-tives are reverse Cassegrains following theSchwarzschild design. Accordingly they havezero chromatic, negligible coma, sphericaland astigmatic aberrations.We currently offer15X and 36X objectivesbroadband coated with aluminum and MgF2overcoat. They are usable from 200 nm to 20 µm. Special coatings are available uponrequest, including MgF2 optimized for the 157 nm to 195 nm region.

These reflecting microscope objectives havesignificant advantages over our conventionalmicroscope objectives. As there are norefracting elements, nor optical cement, theuseful bandwidth is much greater. This is par-ticularly important if good UV or IR perfor-mance is needed. Our design also offers longer working dis-tances and larger numeric apertures than doconventional microscope objectives.

Our microscope objectives use all metal high-ly polished spherical mirrors. The objectivesare designed with two mirrors positioned sothey eliminate aberrations.

The first mirror has a spherical concave sur-face with a center hole. The second mirror issmall, with a spherical convex surface. Themirrors are coated with aluminum and mag-nesium fluoride. Reflection per surface ofeach mirror is 85% average in the UV-VIS,and 90% average in the IR with a dip to 78%at 820 nm.On special order, dielectric coatings opti-mized for 248 and 308 nm are available, andgold for the visible to infrared. See figure onreverse for reflectance curves of metallicreflector coatings.

1. Single material construction (uniform coef-ficient of expansion)

2. Secondary mirror is integral (machined into) to “spider” assembly

3. Objectives are hand assembled in an in-terferometric setup; each pair of mirrors isoptimized as a set for maximum resolu-tion. Typical “spot size”available:

Typical with 15X: 2 µmTypic with 36X: 1 µm4. Near “diffraction limited” performance5. Optical surfaces can be “low scattered”

for use with high power UV lasers.

APPLICATIONS

CONSTRUCTION

THE ADVANTAGES OF THERMOORIEL’S OBJECTIVES

ADVANTAGES OVER COVEN-TIONAL MICROSCOPEOBJECTIVES

HOW THEY WORK

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Wide spectral bandobjectives

Long working dis-tances

High numerical aper-tures

Zero chromatic, negli-gible coma, sphericaland astigmatic aber-rations Above: The Thermo Oriel 15X and 36X reflective microscope objectives.

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Above: A) Diagram of a typical focusing application of a Reflecting Microscope Objective; B) Illustration of therear focal plane of the objective

In a typical focusing application, collimatedlight passes through the aperture hole in thePrimary Mirror , to the Secondary Mirror. TheSecondary Mirror reflects and diverges thebeam to fill the Primary Mirror. The PrimaryMirror focuses the beam to a small spot called theObject Plane or Focal Point (see illustration below).

Secondary Diameter:13595 0.450 inch (11.4mm)13596 0.221 inch (5.6 mm)

Optics Material: Polished, electrolessnickel nickel

Obscuration:13595 27% of full field13596 17% of full field

Max Collection (half angle):............13595 23.6°13596 30°

ORDERING INFORMATIONSPECIFICATIONS

Above: Dimensional diagram of Thermo Oriel’s Reflecting Microscope Objectives

N.A.PowerModelNo.

Price($)

WorkingDistance

(mm)1359513596

0.40.52

15X36X

23.710.4

FocalLength(mm)13.05.4

Field ofView(mm)1.20.5

$ 2,200.00$ 2,400.00

Above: Typical reflectance curves of metallic reflector coatings.

For other powers or for custom specifications, please contact the Thermo Oriel Sales Department.