GaSb-based DBR lasers with high-order Bragg gratings are fabricated without complex process.The16 th-order and 24 th-order Bragg gratings are fabricated with double-trench ridge waveguide by using standard contact optical lithography respectively.The 16 th-order Bragg grating laser achieves single longitudinal mode continuouswave (CW) operation at room temperature with side mode suppression ratio (SMSR) as high as 17.5 d B.The maximum single mode continuous-wave output power is more than 10 mW at room temperature.The laser shows a very excellent wavelength stability against injection current.The single spatial mode operation is maintained in the entire injection current range.The 24 th-order Bragg grating laser even shows a side mode suppression ratio up to22.5 d B at room temperature.The emission wavelength is around 2.0 μm.