Narrow linewidth generation at 1 THz using cascaded Brillouin fiber lasers and quasi-optic UTC-PD

Narrow linewidth THz generation using a cascaded Brillouin fibre laser structure and a unitraveling carrier photodiode is proposed. Using two distributed feedback lasers separated by > 1 THz with 1 MHz initial linewidth, the linewidth of the realized THz source is found to be <; 100 Hz at 1014.7 GHz without use of any active stabilization of the laser cavity or any microwave reference.