We report a self-injection locked InAs/InP quantum-dash tunable laser with ~11 nm (1602-1613 nm) tuning window for next generation multiuser ultra-high capacity fiber/free-space optics (FSO)/hybrid fiber-FSO based optical networks. A tunability of >18 independently locked sub-carriers with ~28 dB side mode suppression ratio (SMSR) and stable (± 0.1 dBm) mode power is exhibited, and an estimated small injection ratio of ~-22 dBm is found to sustain locking and SMSR. Error free transmission of 100 Gb/s and 128 Gb/s externally modulated dual-polarization quadrature phase shift keying (DP-QPSK) signals over 20 km single mode fiber (SMF) and 16 m indoor FSO links, are demonstrated across 8 and 4 individual sub-carriers, respectively, thus covering the entire tuning range. Moreover, up to 168 (192) Gb/s successful transmission over 10 km SMF (BTB) and 176 Gb/s over 16 m FSO link, is achieved on ~1610 nm sub-carrier. Finally, a 128 Gb/s DP-QPSK transmission over 11 km SMF -8 m FSO -11 km SMF hybrid system is accomplished, thus paving the potential deployment of this single-chip, cost-effective and energy efficient tunable light source in multi-terabits/s next-generation passive optical networks (NG-PONs).