10702A Linear Interferometer - HP 5501A Operating And Service Manual

10702A LINEAR INTERFEROMETER
Option 001
I 1,
From
,
Laser --O
.
coo------
\
7T-----
to
Receiver
- J
-
If the 10702A Linear Interferometer i s placed in a beam which has been aligned parallel
to the motion of travel, the outgoing beam can be deflected by as much a s 20 arc-minutes
( 8 )
due to the incoming-outgoing beam parallelism specifications of the 10702A. This
could cause not only cosine error but also possible loss of signal during movement of
the 10703A Retrorefleaor.
To compensate for this, the alignment is performed with the 10702A ~inearlnterferometer
in
This allows the laser beam to be aligned parallel to the motion of travel
to minimize cosine error and maximize signd. since the incoming beam
is
now not parallel
to the motion of travel, the 10702A Linear lnterferometer must remain stationary. (See below)
If the 10702A Linear lnterferometer
is
moved during the measurement instead of the
10703A Retroreflector, the beam in the measurement path will remain parallel but will
be displaced. This displacement S will occur at the receiver causing a decrease and
eventual loss of signal depending on the distance traveled.
-
-
If motion of the Linear lnterferometer is required, the 10702A Option 001 should be used.
This provides special wedge windows which makes the outgoing beam parallel to the
incoming beam. This allows motion by either the 10703A Retroreflector or the 10702A
Option 001 Linear Interferometer.
Figure 2-77. 70702A Linear lnterferometer with Option 007 Windows