Short Focal Length Polychromatic Objectives for UV, VIS and IR
Microscope objectives for focusing laser beams into spatial filters. In holder with standard RMS microscope thread, with four lenses made from synthetic fused silica, not antireflection coated. Aperture ratio about f:3 ; with only some degradation of quality the objectives can be used up to f:2.
| focal length at 266 nm: + 5mm→ OML 8.3.05 | ||
| wavelength | necessary chromatic refocusing | focal length |
| 193 nm 248 nm 266 nm 308 nm 355 nm 532 nm 633 nm 1064 nm |
-0,86 mm -0,14 mm +0,00 mm +0,23 mm +0,39 mm +0,67 mm +0,74 mm +0,88 mm |
4,38 mm 4,90 mm 5,00 mm 5,17 mm 5,29 mm 5,49 mm 5,55 mm 5,65 mm |
| data sheet zum Objektiv OML 8.3.05 | ||
| focal lenght at 266 nm: + 10mm→ OML 8.3.10 | ||
| wavelength | necessary chromatic refocusing | focal length |
| 193 nm 248 nm 266 nm 308 nm 355 nm 532 nm 633 nm 1064 nm |
-1,84 mm -0,29 mm +0,00 mm +0,48mm +0,83 mm +1,41 mm +1,56 mm +1,86 mm |
8,91 mm 9,88 mm 10,07 mm 10,39 mm 10,62 mm 11,01 mm 11,11 mm 11,32 mm |
| data sheet for objective OML 8.3.10 | ||
These objectives are not achromatic because they contain only lenses made from one material. For different wavelengths they must be refocused (according to the data of the table or interpolated). However the optical correction is carried out in such a way that they can be used with good quality at all wavelengths from below 200 nm up to over 1 µm. When used at f:3 they are diffraction limited at wavelengths above 200 nm (OML 8.3.05) resp. 240 nm (OML 8.3.10).
In the optical design of these objectives care has been taken to keep ghost foci (reflections from inner surfaces) away from other optical surfaces. Thus they can be used with strong lasers too. Please note that some of the ghost foci lie within lenses so that the optical power applied to these objectives must stay limited with respect to this fact.
The field of view is comparatively large. Without significant loss of quality these objectives can be used with incident angles of the parallel beam up to a couple of degrees. For this reason it is possible to employ them in imaging applications if it is assured that they are used monochromatic. The microscopic object fields can be chosen up to about 1/3 of the focal length without much degradation of image quality if the apertures are reduced to f:3. These additional stops can be made so that they provide telecentric imaging.
Available on special order
- Antireflection coatings → on request
- assembly with additional stop for telecentric imaging → on request
data sheet