The OP1021 Launch Condition Analyzer is a convenient and compact benchtop Nearfield and Farfield scanner for optical fibers.  Coupled with windows application OPL-LCA, the user can scan and easily plot both the Nearfield and Farfield patterns of any compatible fiber. In addition to comparing the Nearfield and Farfield patterns to standard launch templates, the Encircled Flux is calculated and compared to various IEC templates.

The optical interface of the instrument accepts all standard 2.5mm ferrules. Other connector sizes available upon request.

The OP1021 can be equipped with two internal LEDs with 850nm and 1300nm wavelengths. The internal 105/125µm, 0.22NA fiber allows for overfill testing in most applications.

Nearfield

The Nearfield (NF) describes the optical power density on the surface of a radiating source or the end of a fiber.

The OP1021 complies with IEC 61280-1-4 specifications for a pinhole scanning mechanism to gather the nearfield distribution.  Using a microscope objective, the fiber endface is imaged onto a plane. A pinhole, 100µm in diameter, is situated in front of a detector on this plane and is mechanically scanned across the projected image to gather the nearfield distribution data.

The OP1021 has 3 software controlled positioners to allow for movement in all 3 spatial dimensions.  One allows for bringing the image into focus (z-axis), while two allow the system to scan the projected plane (x, y-axis) for centering purposes. With a +/-250µm effective scan range and a 0.1µm resolution, this nearfield scanner is capable of analyzing the majority of fiber endfaces and launches.

Farfield

The OP1021 conforms to the standards specified in TIA-455-177-B Technique 1 for measuring numerical aperture from the farfield plot.  The farfield scan in the OP1021 is performed by moving a 100µm core fiber along the semicircular arc formed by rotating the normal ray to the input fiber endface in a radial motion.  The receiver is a 100/250µm fiber that is placed approximately 5cm from the endface of the input fiber and can be rotated from -0.5 radians to +0.5 radians about the radial center.

The farfield scan illustrates the farfield profile of a fiber. For multimode fibers, a farfield scan will yield the numerical aperture given the fiber being measured is overfilled.

For single mode fibers, the mode field diameter can be measured from the farfield profile.   The mode field diameter measurement is performed in accordance with TIA/EIA-455-191A and IEC 60793-1-45. The OP1021 uses the direct farfield method to obtain the farfield profile, which is the reference test method for mode field diameter.  An MFD measurement is instrumental in the development and qualification of single mode fiber.


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