Manual Fiber Polarization Controllers
Chapter 2: General Description
Rev H, September 11, 2018
Page 3
2.1. 3-Paddle Fiber Polarization Controllers
A 3-paddle polarization controller combines a quarter-wave plate, half-wave
plate, and quarter-wave plate in series to transform an arbitrary polarization
state into any other polarization state. The first quarter-wave plate would
transform the input polarization state into a linear polarization state. The half-
wave plate would rotate the linear polarization state, and the last quarter-wave
plate would transform the linear state into an arbitrary polarization state.
Therefore, adjusting each of the three paddles (fiber retarders) allows
complete control of the output polarization state over a broad range of
wavelengths from 300 to 2100 nm. The 3-paddle polarization controllers are
available with paddles that support either Ø27 mm loops or Ø56 mm loops.
Using FPC030 as an example for the controllers with a Ø27 mm loop
diameter, a plot of calcuated retardation per paddle versus wavelength is
shown in Figure 1 for a fiber with a cladding diameter of 80
μ
m. For fiber with
a cladding diameter of 125
μ
m, the retardation per paddle versus wavelength
is shown in Figure 2.
