LT-APO/ULWD
apochromatic cryogenic objectives with ultra-long working distance
The ULWD series of LT-APO objectives feature an ultra-large working distance of 12 mm, while maintaining apochromatic performance at comparatively high NA. They are explicetly intended for use with high pressure cells, and hence are designed for diamond anvils / diamond windows with a thickness of 1.55 +/- 0.45 mm. The different versions cover the range from the near UV (VIO), over the visible range (VISIR) to the near-infrared (NIR). Their apochromatic range is mathematically defined by the range over which the focal shift is within +/- the depth of focus around an optimal focus wavelength. Besides, all LWD-LT-APOs on this page are available for 1“ and 2“ sample spaces respectively. For more details, please consult the specification datasheets, or contact our sales engineers.
| Objective | LT-APO/ULWD/VISIR/0.35 | LT-APO/ULWD/NIR/0.35 |
|---|---|---|
| compatible with. | CFM I/cust, AFM/CFM/cust, attoDRY800 | |
| numerical aperture (NA) | 0.35 | 0.35 |
| working distance | 12.0 mm | 12.0 mm |
| AR coating (> 80% trasnmission) | 400 .. 1000 nm | 400 .. 1000 nm |
| apochromatic range(3) (δf < +/- Δ) |
520 .. 870 nm | 670 .. 1105 nm |
| environments | LT, high B-field, UHV | |
| clear aperture | 4.7 mm | 4.7 mm |
| focal length | 6.71 mm | 6.71 mm |
| weight | ~50 g | ~50 g |
| diameter |
24 mm |
24 mm |
| length | 48.35 mm | 48.35 mm |
| suitable broadband collimator | RT-APO/VIS-NIR/0.13 | |
| article number |
1013963 |
1013964 |
| download specs | LT-APO/ULWD/VISIR/0.35 LT-APO/ULWD/VISIR/0.35xs |
LT-APO/ULWD/NIR/0.35 LT-APO/ULWD/NIR/0.35xs |
(1) Possible use with solid immersion lenses: half-ball radius < 0.65 (0.70) mm for unlimited lateral displacement or half-ball radius < 1.40 mm for coaxial approach only
(2) 4 options available: coating A 400-600 nm | coating B 600-1050 nm | coating C 1050-1600 nm | uncoated
(3) δf: chromatic focal shift, Δ = n*λref / (2*NA2): depth of focus, n: refractive index, λref : wavelength used to define focal plane with max. Δ
(4) glas transmission: see respective objective data sheets
(5) RT-APO: > 96% transmission
Naming Scheme
The different objectives offered are distinguished and described by the following naming scheme:
RT is short for “Room Temperature (compatible)“.
LT is short for “Low Temperature (compatible)”.
IWDO is short for “Intermediate Working Distance Objective”.
LWD is short for “Long Working Distance”.
LWDO is short for “Long Working Distance Objective”.
APO is short for “Apochromatic”, and refers to the fact that the focal displacement curve is flat (i.e. within plus/minus one depth of focus) within the specified apochromatic range (see specification sheets of the respective objectives for further details).
/VIO indicates that the objective is most suitable in the ultra-violett to visible range
/VIS indicates that the objective is most suitable for the visible wavelength range.
/VISIR indicates that the objective is most suitable for the visible to (near-)infrared wavelength range.
/IR indicates that the objective is most suitable in the lower infrared range
/NIR indicates that the objective is most suitable for the near-infrared wavelength range.
/0.82 is indicating the numerical aperture (NA) of the respective objective, in this case NA = 0.82.