HP 86037B, Instruction Manual

Page: 172 / 204

7-2
Reference
Theory of Operation
Theory of Operation
The HP 86037B uses the modulation phase-shift measurement technique for
performing near-end measurements, where there is access to both fiber ends
at the same location. A diagram of a measurement apparatus based on the
modulation phase-shift technique is shown in
Figure 7-1 . This system is most
useful in fiber, grating and cable manufacturing, as well as for testbed evalua-
tion and system manufacturing.
Figure 7-1. Measurement of chromatic dispersion using the phase-shift method
Figure 7-2 through Figure 7-4 show three block diagrams of the most common
system options. There are several other options which are discussed later in
this chapter. The RF source of an HP 8753 RF network analyzer drives an opti-
T u n a b le
N a rro w b a n d
O p tic a l S o u rc e
W a v e le n g th M e te r
Inte ns ity
M od u lator
C o m p a re P h a s e s
R e la tiv e G ro u p D e la y
D is p e rs io n
P h o to d io d e
R e c e iv e r
M o d u la to r
D rive
R e fe re n c e
D e v ic e U n d e r T e s t
C o m p u ta tio n & D is p la y
E le c tric a l
S o u rc e
f λ
0