https://doi.org/10.1140/epjd/e2010-00247-8
All-fiber wavelength tunable passively mode-locked erbium-doped ring laser
Department of Physics, Hebei Normal University, 050016, Shijiazhuang, P.R. China
Corresponding author: a zhangsm@mail.hebtu.edu.cn
Received:
10
December
2009
Revised:
28
June
2010
Published online:
28
September
2010
An all-fiber, wavelength-tunable, passively mode-locked
erbium-doped ring laser is presented. Erbium-doped fibers (EDF) are used as
the gain media because of their large gain bandwidth. Nonlinear polarization
rotation (NPR) plays the dual role of realizing mode-locking and effectively
adjusting the intensity-dependent loss of the cavity. An unbalanced
Mach-Zehnder interferometer (UMZI) is used as a tunable optical beam
filter. By using the UMZI and adjusting the polarization controllers (PCs),
a sub-picosecond mode-locking laser is realized that is self-starting
with central lasing wavelengths that can be accurately tuned
over a range of about 
30 nm and also has controllable spacings
between different tunable wavelengths.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010
