Optical Output - Keysight N777-C Series User Manual

2 Getting Started

Optical Output

32
Polarization Maintaining Fiber
All Keysight N777-C Series Tunable Laser Family instruments include
polarization maintaining fiber (PMF) outputs, aligned to maintain the state
of polarization.
The fiber is of Panda type, with TE mode in the slow axis in line with the
connector key. A well-defined state of polarization ensures constant
measurement conditions.
Stress Rods
Figure 10
Angled Contact Connectors
The N777-C Series Tunable Laser instruments are outfitted with an angled
polished connector. Angled contact connectors help you to control return
loss. With angled fiber end-faces, reflected light tends to reflect into the
cladding, reducing the amount of light that reflects back to the source.
When reflected light remains in the fiber core at two or more locations
along the optical path, such as at an open straight-polished connector
output to a power meter, double reflections result in multi-path
interference of the coherent light and thus power instability in the
measurements.
E
Slow Axis (Polarization Axis)
Not to Scale
PMF Output Connector
Keysight N777-C Series Tunable Laser Family User's Guide
Connector Key
Fiber Cladding
H
Fiber Core
(9-μm Diameter)