Fiber Coupler series 60FC-K

compatible with the kinematix® optomechanics

Fiber coupler 60FC-K-4
Fiber coupler 60FC-K-4
Fiber coupler 60FC-K-4
Fiber coupler 60FC-K-4
Fiber coupler 60FC-K-4
Representative product images. Individual product images are found on the individual product pages.

Features

The fiber couplers series 60FC-K are compatible with the kinematix® optomechanics and can be used for coupling into single-mode or polarization-maintaining fiber cables or as a fiber collimator.
  • Focal lengths up to 18 mm
  • Choice of aspheres, monochromats, achromats and apochromats
  • Various AR coatings for UV - IR
  • Choice of fiber receptacles: FC PC or FC APC (standard), many others available
  • Compatible with kinematix® optomechanics


Description

The fiber collimators series 60FC-K are compatible with the kinematix® optomechanics and can be used for coupling into single-mode or polarization-maintaining fiber cables or as a fiber collimator. They are suitable for single-mode and polarization-maintaining fiber cables leading to collimated beams with a Gaussian intensity profile. Please note that for multimode collimation the intensity profile is not Gaussian and depends on specific fiber and radiation properties.

An optics for each application
A large variety of collimating optics allows that the optimum focal length and the best lens type for a single wavelength (monochromat) or a wavelength range (achromat or apochromat) can be selected for each application. All lenses are AR-coated.

Adjustment of focus
The distance between fiber end-face and collimating optics is adjusted by means of an eccentric key. The lens does not rotate when adjusting the focus. The final focus setting is locked by means of two radially arranged clamping screws.

Optimum lens performance 
The angled polish of connectors of type APC is considered by a pre-angled mechanical coupling axis that compensates the beam deflection and you can use the lens centrically. This minimizes aberrations simply resulting from a non-ideal beam path through the lens.

Connector Type  
The fiber collimator can be equipped with FC PC (wide key*), FC APC (wide key*), or LSA (compatible with fiber connectors type DIN, AVIO and AVIM) receptacles. F-SMA type receptacles are available for 0° and 5° or 8°-polish e.g. for SMA-905 High Power connectors. In case of FC or LSA with a spring loaded ferrule the fiber coupler has an additional grub screw to increase pointing stability. *Even though the fiber coupler has a wide key receptacle it still can be used with both narrow key and wide key fibers. More information can be found here.

Material 
The fiber collimators are made of nickel silver and stainless steel.

Mounting
The fiber coupler needs to be placed into kinematix® optomechanics (not included) in order to be used as in- or outcouplers.

Technotes

FAQ

  • Adjustment
    • How much can I change the focus setting?
      You can change the focus setting ± 2.0 mm. 
    • I do not have a collimating telescope to collimate. Can you give me practical advice?
      Of coarse, a collimating telescope is the best way to collimate. But there are other methods depending on the type of fiber (single-mode and PM vs. multimode) you can use. Please refer to our practical collimating tips here.
    • I am unsure how to correctly adjust my coupler/collimator. Where do I find details about the adjustment procedure?
      Please refer to the manual in the Downloads section for a detailed adjustment procedure.
  • Fiber Receptacle
    • FC PC and FC APC
      • How do I attach a fiber cable?

        1. To prevent damage to the sensitive fiber end-face, always insert the fiber connector`s ferrule at an angle, with the connector key properly aligned to the receptacle notch.
        2. When the ferrule tip is safely located in the inner cylinder of the receptacle, align the connector to the receptacle axis and carefully introduce the connector into the fiber coupler.
        3. Then, orient the connector key in a way that it is pressed gently onto the right-hand side of the receptacle notch ("right-hand orientation rule").
        4. Gently screw on the connector cap nut onto the receptacle until it is finger-tight.
        5. Gently tighten the fiber grub screw to reduce the free play of the ferrule in the receptacle.

      • What is the "right-hand orientation rule"?

        When the ferrule tip is safely located in the inner cylinder of the receptacle, align the connector to the receptacle axis and carefully introduce the connector into the fiber coupler. 

        Then, orient the connector key in a way that it is pressed gently onto the right-hand side of the receptacle notch.

        The tightened grub screw and the "right-hand orientation rule" for the connector, ensure a high reproducibility in mode field position and angle, which is especially important for attaching and reattaching polarization-maintaining fibers reproducibly.

      • Can I attach a narrow key fiber cable to a fiber coupler with a wide key receptacle?

        Yes you can- without any problem. Simply adhere to the "right-hand orientation rule".

        Generally, with any FC PC or FC APC type connector there is a freeplay when inserting the fiber into the fiber coupler. The free play in between the connector ferrule and receptacle is only a few microns, but necessary for inserting the ferrule without force. There is a difference between the receptable and key width for wide key (2.14 mm) and narrow key (2.0 mm) fibers. If you follow th so-called "right-hand orientation rule" you can reproducibly attach and reattach even PM fibers  with narrow key receptacle to fiber couplers with wide key receptacle without difficulty.

        "Right-hand orientation rule":

        When the ferrule tip is safely located in the inner cylinder of the receptacle, align the connector to the receptacle axis and carefully introduce the connector into the fiber coupler. Then, orient the connector key in a way that it is pressed gently onto the right-hand side of the receptacle notch.The tightened grub screw and the "right-hand orientation rule" for the connector, ensure a high reproducibility in mode field position and angle, which is especially important for attaching and reattaching polarization-maintaining fibers reproducibly.


  • Troubleshooting
    • I can‘t collimate the radiation out of a coupler. Why?
      • Have you loosened the grub screws?
        The clamp screws have to be loosened before changing the focus setting, Please refer to the adjustment instructions of the individual couplers for more details.
      • Have you checked, if the fiber is correctly placed within the fiber receptacle of the coupler?
        The fiber connector might not be placed correctly within the receptacle of the coupler. In particular, please check the small grub screw holding the connector's ferrule (e.g. for FC PC and FC APC type couplers). It might be in the way. Please refer to the adjustment instructions of the individual couplers for more details.
      • Have you tried another eccentric key?
        Please check, if the eccentric key is damaged or broken.

        Please also check, if you are using the appropriate eccentric key. The eccentric key type 60EX-5 has a larger stroke compared to the key type 60EX-4. The 60EX-5 is used for couplers with focal length ≥ 12 mm. The 60EX-4 is used for focal lenghts < 12 mm.

        In some very, very rare cases the stroke of the original eccentric key may be too small for the coupler in your applictation. (See FAQ "Difference between 60EX-4 and 60EX-5"). Try using the 60EX-5 in this case.
      • Have you checked the eccentric key for damage?
        The eccentric key might be damaged or broken. If that is the case, try another eccentric key of the same type and (or) contact Schäfter+Kirchhoff for replacement.

Downloads

Adjustment_60FC-K.pdf (Manual)

This downloads section only includes general downloads for the complete series.
Please access the individual product pages (using the product configurator, the product list, order options or the search button if you have a complete order code). Here you will find specific downloads including technical drawings or stepfiles.