Nanosecond passively Q-switched fiber laser in the 1.5 µm region using turmeric saturable absorber

•Turmeric PVA film was fabricated for saturable absorber (SA) application.•Q-switched laser was achieved at 1566.96 nm.•The maximum pulse energy was 150.96 nJ.•The minimum pulse width was 725 ns.•The results indicate that the turmeric film performed better than other SAs.