What is a
qualified patchcord?
Many manufacturers
over-emphasize the performance
of back reflection and insertion loss
figures but ignore the importance of
topography measurement of the polished
ferrule. The three main important measurements
that characterize the shape of the polished
connector endface are radius of curvature,
vertex offset and undercut.
Radius
of Curvature
This
is defined as the radius
of curvature of the portion of the
endface that is domed by polishing
for physical contact.
Vertex
offset
Vertex offset indicates how well the sphere forming the
connector endface is centered on
the fiber. It is measured by determining
the position of the highest point
of the endface and measuring the
distance between this point and
the centre of the fiber
Undercut
Undercut
is the difference in height
between the surface of the ferrule
and the surface of the fiber. Undercut
is usually measured by finding two
points which lie on the centerline
of the fiber. One point lies where
the sphere forming the surface of
the ferrule intersects the centerline
of the fiber. The second point lies
where the surface of the fiber intersects
the centerline of the ferrule. The
distance between these two points
is the undercut. Serious undercut
can be seen at above picture.
ZJOPTIC
Standard of topography measurement
of polished ferrule
| Measurement
Parameter |
Pass/
Fail Limits (Min) |
Pass/Fail
Limits (Max) |
| Radius of
Curvature |
10.0 mm |
25.0 mm |
| Fiber Height
(Spherical Fit) |
-50.0 nm |
50.0nm |
| Fiber Height
(Planar Fit) |
-10.0 um |
150.0 nm |
| Apex Offset |
-0.00 um |
50.0 um |
| Angle |
-0.3 degree |
0.3 degree |
| Fiber Roughness
(Rq) |
0 nm |
50 nm |
| Ferrule Roughness
(Rq) |
0 nm |
50 nm |
| Diameter |
125.0 um |
135.0 um |
Guaranteed Performance
by ZJOPTIC
| |
APC |
UPC |
PC |
Insertion
Loss (dB) |
<0.2 |
<0.2 |
<0.2 |
Return
Loss (dB) |
>60 |
>50 |
>45 |
Testing System
In order to assure a satisfactory performance, a rigid testing procedure
is applied to every patchcord assembled
by ZJOPTIC. The aim of this testing
procedure is to make sure every ZJOPTIC
patchcords are in best condition before
delivery.
Insertion Loss Test - For
singlemode fiber optic cable
When tested in accordance with the GR-326-CORE, the maximum
insertion loss shall not exceed 0.2dB
against master connector. We apply company standard is max 0.2dB. ZJOPTIC
typical value is 0.1dB.
For multimode fiber optic
cable:
In accordance with FOTP-34 (interconnection device insertion
loss test) and FOTP-171 (attenuation
by substitution measurement), all
tests are performed by advanced testing
equipment. The maximum insertion loss
shall not exceed 0.2dB against master
connector. Again, typical value is
0.09dB.
Return Loss Test-For singlemode
fiber optic cable only:
Strictly following FOTP-107, JDS-Uniphase RX and RM series
Power and Back Reflection Meter is
used as testing instrument.
Ferrule Surface Inspection
Every connector is inspected by 400X microscope to ensure
there is no visible scratch on the
fiber.
Topography measurement of
the ferrule
DORC interferometer can
display an accurate measurement
of radius of curvature, fiber height,
apex offset, fiber roughness and
ferrule roughness. Sample checked
by our QC manager could make sure
all the critical parameters are
within specifications defined by
international organizations.
