In order to connect the measurement head or optical probes to the spectrometer, Instrument Systems supplies a range of optical fiber guides (OFG-xxx). These are not attached directly to the spectrometer, but instead to a fiber plug adapter (PLG-xxx) appropriate for each fiber type. The fiber plug adapter is then mounted on the spectrometer's entrance port. This innovative concept means that calibration of the spectrometer remains intact when changing the accessories attached.

Properties of the different fiber guides:

Type	Features	Advantages	Application
multimode fiber with SMA connector	multimode fiber with core diameter 200 - 1000 µm	superior light transmission for small beam diameters	collecting and transmitting collimated light
fiber bundle with ferrule	bundle of fibers each with core diameter of 50 µm	large cross sections possible; bending the fiber does not affect transmission	collecting and transmitting diffuse light

Ordering information for fiber guides:

Model	Diameter	Spectral range	Features
Multimode fiber with SMA connector
OFG-311 / -312 / -313	200 / 600 / 1000 μm	300 - 2200 nm	glass fiber
OFG-321 / -322 / -323	200 / 600 / 1000 μm	190 - 1350 nm	quartz glass fiber
OFG-352	400 μm	1000 - 6000 nm	chalcogenide fiber
Fiber bundle with SMA connector
OFG-343	1 mm	280 - 2500 nm	LIR fiber
Fiber bundle with ferrule
OFG-414 / -415	1.5 / 3 mm	380 - 1600 nm	glass fiber
OFG-424 / -425	1.5 / 3 mm	190 - 1350 nm	quartz glass fiber
OFG-444 / -445	1.5 / 3 mm	280 - 2500 nm	LIR fiber
OFG-464 / -465	1.5 / 3 mm	190 - 2500 nm	mixed fiber bundle
Bifurcated fiber bundle with ferrule; 2 arms combined to 2.1 mm Ø
OFG-524	1.5 mm	190 - 1350 nm	quartz glass fiber
OFG-554	1.5 mm	190 - 1600 nm	mixed fiber bundle
OFG-555	1.5 mm	190 - 2500 nm	mixed fiber bundle
Fiber bundle cross section conversion
OFG-625	3.6 mm	190 - 1350 nm	changes cross section to 2 x 5 mm

Instrument Systems supplies appropriate connector adapters for both multimode fibers and fiber bundles. Fiber plug adapters are also available for all popular connectors as used in optical telecommunications and fiber sensor applications.

The fiber plug adapter slides into the optical input of the spectrometer and is fixed with the knurled ring. An alignment pin guarantees accurate and reproducible installation. Furthermore, the fiber plug adapter ensures efficient coupling of the light into the spectrometer due to the integrated lens that matches the fiber NA (numerical aperture) to the f-number of the spectrometer.

Ordering information for fiber plug adapter PLG:

SMA connector	Fiber bundle ferrule	Spectral range	Transmission
PLG-310	PLG-410	300 - 2200 nm	optimized for VIS
PLG-320	PLG-420	190 - 3200 nm	optimized for UV
PLG-340	PLG-440	190 - 3200 nm	optimized for IR
PLG-350	n/a	1000 - 5000 nm	optimized for IR

Additionally, the PLG adapters of the type PLG-53x are compatible with the connectors popular in optical telecommunications: FC/PC, ST, DIN, Radiall, Diamond.