The Santec TSL-570 is a tunable laser for wavelength-dependent optical testing, photonics research, and component characterization. Available configurations cover different bands within 1240–1680 nm rather than one continuous range on every unit. The source lists sweep speeds up to 200 nm/s and a 0.1 pm wavelength setting resolution. Type A, C, and P configurations have different accuracy specifications. Ethernet, GPIB, and USB interfaces support automated setups, including systems that combine power measurement, optical switching, and polarization control.