COLLIMATORS, FOCUSERS
This generic name of colimators  refers to components which modify the beam angle to obtain a given diameter at a precisely given length (the focal length). We call the component "colimator" when the beam obtained is parallel and "focuser" when the beam is convergent. 

The proposed products are pigtailed components. They are very precise assemblies of an optical lens, a SM or MM fiber and a packaging. According to the type of fiber used and the performances requested several technologies are used with two lens families:
- Selfoc lens (self focusing lens)
- Traditional lens

SELFOC COLLIMATORS

Selfoc lens are graded index cylinders with a focal point on both end of the cylinder where the fiber can be positioned. The length of the cylinder is precisely adapted by polishing to the wavelength. Angle polishing allows back reflexion reduction and AR coating can be proposed for even better performances. Typical beam diameter obtained are 300µm to 400µm. This technology is adapted to small diameter fibers SM or GI.
It is possible to use selfoc lens with bigger fibers like HCS fibers but the result is not a colimator but a NA reductor in this case which can be very interesting for some applications.

COLLIMATORS WITH TRADITIONAL LENS
For many specifications selfoc lens cannot be used (fiber diameter, NA, power, spot size and focal length needed). Traditional lens offer a number of possibilities in this case but some trade-off have to be made in the specifications required. For instance the longer the focal length the better the colimator. But the diameter of the lens to obtain the NA required may become very big. Besides the packaging has to be adapted to each particular requirement according to the focal length and lens diameter needed.