  We report the design of a microstructured silica-based fiber for widely
tunable soliton self-frequency shift, suitable for pumping with two most common
fiber laser wavelengths: 1.04 {\mu}m and 1.55 {\mu}m. Depending on the pump
source, the output spectrum can be continuously tuned up to 1.67 {\mu}m (pump
at 1.04 {\mu}m) or 1.95 {\mu}m (pump at 1.55 {\mu}m) in the same 1.5 m-long
fiber sample, with pump-to-soliton conversion efficiency higher than 20%. The
fiber is highly birefringent, which results in an excellent polarization
extinction ratio of the soliton, reaching 26 dB. The shifted solitons have a
high degree of coherence confirmed by pulse-to-pulse interference measurement.
The available soliton tuning range covers the wavelengths inaccessible for
fiber lasers, e.g., 1.3 {\mu}m and 1.7 {\mu}m, highly important for
multi-photon microscopy and imaging. Our work shows that it is possible to
design and fabricate one universal optical fiber that supports soliton shift
when pumped at two different wavelengths separated by over 500 nm.
