Fig. 1. Schematic diagram of Z-folded off-axis hybrid unstable resonator. (a) Gas flow direction of gain medium (X direction)；(b) height direction of gain medium (Y direction). Laser optical axis direction is Z direction

Fig. 2. Virtual assembly diagram of gain generation module and optical cavity module

Fig. 3. Schematic diagram of monitoring optical path for power, far-field spot and spectrum of output beam

Fig. 4. Far-field spots of output beam in numerical calculation. (a) Gain size in gas flow direction is limited to 10 mm；(b) gain size in gas flow direction is limited to 8 mm; (c) gain size in gas flow direction is limited to 6.5 mm

Fig. 5. Far-field spots of output beam in experiment. (a) Gain size in gas flow direction is limited to 10 mm；(b) gain size in gas flow direction is limited to 8 mm; (c) gain size in gas flow direction is limited to 6.5 mm

Fig. 6. Laser spectrum