Hybrid polymer/InP dual DBR laser for 1.5 mm continuous-wave terahertz systems

A hybrid polymer/InP dual DBR laser at 1.5mm is presented as an optical source for heterodyne generation and detection of cw-THz signals. The device consists of an active InP chip as an active gain element, end-fire coupled to a polymer chip with thermo-optically tunable phase shifters and Bragg gratings. Mode-hop-free tuning of 1.1 THz has been achieved on the single DBR lasers. The usability of such sources for heterodyne cw-THz generation has been demonstrated in a coherent cw-THz setup. Scans in the THz range show a resolution of the H2O absorption lines comparable to the results achievable with commercially-available external-cavity diode lasers.