Thorlabs' TLX3 O-Band Tunable Laser is a turnkey, self-contained, tunable laser for the O-Band (1250 nm to 1350 nm) wavelength range based on the use of a fiber-coupled, semiconductor gain module and an intracavity tunable filter. This instrument has no moving parts, which enables continuous wavelength tuning at up to 400 nm/s, as well as 10 pm tuning resolution and ±50 pm wavelength accuracy. With output power in the 10 mW to 40 mW range and polarization-maintaining single mode output, it is an ideal source for communication applications and manufacturing testing. For maximum measurement flexibility, this tunable laser can be operated in three modes, which include manual, stepped sweep, and continuous sweep.