Patent ID: 8885682

Claim:
A laser device for emitting waves within a frequency range of between 0.5 THz and 5 THz comprising a semiconductor heterostructure with a substantially cylindrical shape with a circular cross-section, said heterostructure comprising: a first layer in an optically nonlinear semiconductor material including emitters configured to emit in at least two optical whispering gallery modes belonging to the near-infrared spectrum, said at least two whispering gallery modes being confined within said first layer and enabling the generation, within said first layer, of radiation within an electromagnetic whispering gallery mode with a frequency of between 0.5 to 5 THz, said radiation being generated by the difference in frequency of said two whispering gallery modes, the substantially cylindrical geometry of said heterostructure ensuring phase tuning between the two optical whispering gallery modes belonging to the near-infrared spectrum and the terahertz mode at the difference in frequency; a second and a third semiconductor material layer, each presenting a smaller optical index than the index of the material used for said first layer and located on both sides of the first layer; at least one metal layer located on one end of said heterostructure; wherein said heterostructure includes in its center a hole with a substantially cylindrical shape extending over the entire height of said heterostructure, a radius of said hole being chosen to establish the phase tuning; a deviation between a radius of the cylinder forming said heterostructure and the radius (R int ) of the hole is greater than 0.05 × λ THz η THz where λ THz is the emission wavelength in the frequency range of between 0.5 THz and 5 THz and n THz is the effective index of propagation of the terahertz mode at the wavelength λ THz .