Teledyne LeCroy WaveExpert 100H Operators Manual - Manual (Page 60)

Operator’s Manual
58
WE-OM-E Rev A
Connector Torque
In order to maintain bandwidth performance and minimize loss, connections to the instrument
modules should be torqued to the appropriate tightness. The connectors all have standard 3/8 inch
nuts on them and should be torqued to 8 in-lbs. using an appropriate torque wrench. The 100 GHz
module has a unique connector that requires a smaller torque value of 4 in-lbs. This module is
supplied with the appropriate torque wrench.
Optical Modules
Several optical modules are also available for use with the WaveExpert mainframe. The modules
are outlined in the table below. Optical modules are available in single-mode and multimode
configurations. The single-mode modules are designed to operate over wavelengths in the 1280 to
1620 nm range, while the multimode module covers the 750 to 1620 nm range. Single-mode and
multimode fibers are characterized by different diameters. Multimode fiber, as its name implies,
allows many “modes” or group velocities to propagate, while single-mode allows only one. The
diameter of multi-mode fiber is much larger than that of single-mode fiber (50 to 62.5 nm vs. 9.5 nm)
so connecting a multimode fiber to a single-mode one will result in a large amount of signal
attenuation caused by the difference in area of the connector faces. Since the energy in a
multimode signal is spread out into the many modes propagating in the fiber, at the boundary with
the single-mode fiber only one of these modes will pass through.
Module Wavelength Range Fiber Type Fiber Diameter
SO50 1280-1620 nm Single mode 10 µm
SO25 1280-1620 nm Single mode 10 µm
SO10 750-1650 nm Multimode 62.5 µm
Single-mode fiber has a narrow core diameter that allows only one mode to propagate. This type of fiber is very
low loss, so it is the choice for long-haul communications.
Multimode fiber has a much wider core diameter that allows many modes to propagate. This type of fiber has
higher loss, but is less costly, is easier to work with, and is the choice for LAN and other short-haul applications.
The optical modules come standard with an FC-PC connector, and adapters are available for a
variety of other optical connector types. Adapters can be easily swapped on the optical module