Description
MID-IR Focusing and Collimating Objectives are designed to use with Infra-Red fiber optic cables and bundles.
The housing of the lens easily connects to fiber optic cables either with FC/PC or with SMA connectors and enables Z-axis alignment.
Thread adaptors are suitable to mount lens objectives to Thorlabs optical components with SM1, RMS and S-Mount.
Mid-IR Lenses are available with anti-reflection (AR) coating for two spectral ranges:
- 3-5µm – for chalcogenide fiber cables
- 8-12μm – for silver halide fiber cables
Table of Refocusing Objectives
| Code | FORO-L-3/5-F10 | FORO-L-8/12-F10 | FORO-S-3/5-F5 | FORO-S-8/12-F5 |
| ZnSe Lens | Double-convex Ø 15 | Double-convex Ø15 | Plano-convex Ø 5 | Plano-convex Ø 5 |
| AR Spectral Range | 3-5µm | 8-12µm | 3-5µm | 8-12µm |
| Lens Focal Distance | 10 mm | 10 mm | 5 mm | 5 mm |
| Numerical Aperture | 0,35 | 0,35 | 0,25 | 0,25 |
| Outer Diameter | 25 mm | 25 mm | 12 mm | 12 mm |
| Connecting Thread | M24x1 | M24x1 | no | no |
| Length (approx.) | 37 mm | 37 mm | 23 mm | 23 mm |
| Alignment Options | Z-axis positioning | Z-axis positioning | Z-axis positioning | Z-axis positioning |
| SMA Adapter | YES | YES | YES | YES |
| FC/PC Adapter | On Request | On Request | On Request | On Request |
| Housing | Aluminium Black anodizing | Aluminium Black anodizing | Aluminium Magenta anodizing | Aluminium Magenta anodizing |
Table of Collimating Objectives
| Code | FOCO-L-3/5-F20 | FOCO-L-8/12-F20 | FOCO-S-3/5-F5 | FOCO-S-8/12-F5 |
| ZnSe Lens | Plano-convex Ø 15 | Plano-convex Ø15 | Plano-convex Ø 5 | Plano-convex Ø 5 |
| AR Spectral Range | 3-5µm | 8-12µm | 3-5µm | 8-12µm |
| Lens Focal Distance | 20 mm | 20 mm | 5 mm | 5 mm |
| Numerical Aperture | 0,35 | 0,35 | 0,4 | 0,4 |
| Outer Diameter | 25 mm | 25 mm | 14 mm | 14 mm |
| Connecting Thread | M24x1 | M24x1 | no | no |
| Length (approx.) | 37 mm | 37 mm | 23 mm | 23 mm |
| Alignment Options | Z-axis positioning | Z-axis positioning | Z-axis positioning | Z-axis positioning |
| SMA Adapter | YES | YES | YES | YES |
| FC/PC Adapter | On Request | On Request | On Request | On Request |
| Housing | Aluminium Black anodizing | Aluminium Black anodizing | Aluminium Magenta anodizing | Aluminium Magenta anodizing |
Transmission Spectra
MID-IR Refocusing Objectives (FORO)
Collimating Objectives for Mid IR-Fiber Cables (FOCO)
- Focusing the beam out of the fiber or, used in reverse, into the fiber
- Collimating the beam out of the fiber or, used in reverse, focusing of collimated beam into the fiber
- Fiber end/bundle imaging to the detector
Using a lens to collect the radiation into the optical fiber
The area S is limited by the numerical aperture of the optical fiber. The fiber “sees” the radiation exiting from each point within the area S.
The radiation reaching the fiber end is proportional to the angle d1/L, where d1 is the fiber diameter, L is the distance between S and fiber end.
To increase the radiation collected into the fiber, it is necessary to put a lens between S and fiber end, then the signal is proportional to d2/L, where d2 is the lens diameter (d2 > > d1).
Focus distance F and the lens diameter d2 should agree with the numerical aperture of the fiber.
Do you have any questions about this or any other product? Send us an inquiry, and our personnel will answer your question as soon as possible.
