In this work, we present GaInAs/AlAs/AlInAs quantum cascade lasers emitting from 3.2 to 3.4 μm. Single-mode emission is obtained using buried distributed-feedback gratings fabricated using standard deep-UV contact lithography. This technique can easily be transferred to industrial production. Devices with single-mode emission down to 3.19 μm were achieved with peak power of up to 250 mW at -20 °C. A tuning range of 11 cm(-1) was obtained by changing the device temperature between -30 °C and 20 °C.