Wavelength tunable lasers operating at near infrared (NIR) wavelength are demonstrated through the thermo-optic (TO) refractive index tuning of polymer waveguide Bragg reflectors. The polymer-waveguide device has superior TO efficiency for substantially changing the refractive index, and it enables direct tuning of the Bragg reflection wavelength over a wide range. The waveguide is optimized for NIR wavelengths, and a third-order Bragg reflector is incorporated for facilitating fabrication of the grating. The laser exhibits an output power of 0 dBm, a side-mode suppression ratio of 40 dB, and a tuning range of 21 nm.