Broadband polarization-maintaining, single-mode fiber cables PMC-RGB with Gaussian intensity distribution and low-stress fiber connectors.
The fiber is a polarization-maintaining, single-mode fiber, defined by its NA and its cut-off wavelength. The nom. NA is specified by the fiber manufacturer. Additionally the effective numerical NAe2 is measured for each fiber batch by Schäfter+Kirchhoff. The fiber has a pure silica core fiber with a cut off below a wavelength of 400 nm. It is suitable for wavelengths up to 680 nm. However, at long wavelength this fiber is quite sensitive to disturbances, such as bending or stress.
During the manufacturing process of fiber cables of type PMC-400RGB additional measures are taken to guarantee a high performance even at high wavelengths. Additional tests are performed to document that the fiber performance is high over the whole wavelength range.
The fiber length can be customer-specified (there is a minimum fiber length). The polarization-maintaining fiber cables are offered as Ø 900 µm buffer in black, or a Ø 3 mm cable in black with Kevlar strain-relief.
For each fiber end the fiber connectors can be selected from a wide range of connector types (FC, DIN or AVIO) with 0°-polish or 8°-polish. All fiber connectors of type FC assembled by Schäfter+Kirchhoff have an alignment index (key). The wide key (type "N") fiber connector has an alignment index (key) of 2.14 mm width. The narrow key (type "R") fiber connector has an alignment index (key) of 2 mm width. Special fiber connectors are available so that the fiber cable is vaccum compatible down to 10-7 mbar (only Ø 900 µm buffer fiber cables).
High PER fibers
During the manufacturing of PM fibers, great care is taken to ensure a high PER. Typical PER values are ≥21 dB to ≥ 26 dB depending on wavelength and connector type.
The fiber connectors can be equipped with an end cap connector. This means that a short piece of fiber (< 300 µm) without a core is spliced onto the polarization-maintaining fiber. Without a fiber core to confine the beam, the mode field diameter of the beam already starts to diverge within the fiber end cap, significantly reducing the power density at the fiber end-face.
Amagnetic fiber connectors
For FC PC or FC APC type connectors amagnetic versions completely made of titanium can be selected. Those connectors have a ceramic ferrule.