  Ultrafast all-fiber Yb-doped fiber oscillators are usually associated with
all-normal-dispersion cavities, which operate in a dissipative soliton regime,
quintessential for pulsed operation at the wavelength of 1 {\mu}m. This work
presents an all-polarization-maintaining Yb-doper fiber laser oscillator that
operates in a dispersion-managed dissipative soliton regime, thanks to
incorporating a chirped fiber Bragg grating. The oscillator, mode-locked via a
nonlinear optical loop mirror, has an unconventional semi-linear cavity of net
anomalous dispersion. Unlike in standard ring resonators, the ultrashort pulse
undergoes amplification twice per cavity roundtrip. Additionally, we report a
duality of pulsed operation states depending on the pumping power. Strikingly,
the oscillator can work in a~subregime similar to the standard dissipative
soliton, facilitating further energy scaling at anomalous dispersion. We
characterize the low-noise setup capable of delivering pulse energy as high as
6.4 nJ using standard single-mode polarization-maintaining optical fibers.
