Patent ID: 8649414

Claim:
A frequency tunable terahertz transceiver comprising: a dual wavelength laser including two distributed feedback lasers that are manufactured in one substrate and output optical signals of respectively different wavelengths; and an optical device receiving the outputted optical signals to generate a terahertz wave, each of the distributed feedback lasers including a lower clad layer, an active layer formed on the lower clad layer and generating an optical signal, a upper clad layer formed on the active layer, a Bragg diffraction grating interposed between the upper clad layer and the active layer and oscillating the generated optical signal according to an effective refractive index, a passive waveguide interposed between the lower clad layer and the upper clad layer and delivering the optical signal from the active layer directly to the optical device, a first end of the passive waveguide being coupled with the active layer by butt coupling with a predetermined coupling angle and a second end of the passive waveguide being coupled directly with the optical device, a p-type semiconductor layer formed on the upper cladding layer, an electrode formed on the p-type semiconductor layer, an insulation layer formed on the electrode, a microheater formed on the insulation layer and controlling the effective refractive index of the distributed feedback lasers, and a thermal diffusion preventing region formed between the distributed feedback lasers and having a greater depth than the active layer to prevent thermal diffusion, and the optical device including a lens receiving the optical signals from the two passive waveguides separately from each other, combining the optical signals and irradiating the combined optical signals on a photomixer, the photomixer receiving the combined optical signals from the lens to generate the terahertz wave.