The terahertz region of the electromagnetic spectrum, in particular the region of 1-10 THz, is called the “terahertz gap” due to the lack of convenient radiation sources which are either inefficient or require cooling and are not tunable in frequency.
The method relies on a proven ability to impose coherence of the electronic states in a practical semiconductor with timescales corresponding to the THz radiation. A short optical pulse is directed to a semiconductor optical amplifier being at a temperature above 0° and induces coherent oscillations at the desired THz frequency range. The semiconductor optical amplifier or a diode laser are biased electrically to gain conditions. These THz oscillations, initiated by the pulse, are a manifestation of Rabi Oscillations in the semiconductor optical amplifier, and emit light at a frequency of at least 1 THz. Their frequency is controllable by the pulse intensity so the frequency is tunable.
- Operates completely at room-temperature
- Simple to construct and robust
- The emitted radiation frequency is tunable
- Entire source can have a very small footprint
Applications and Opportunities
- Medical imaging without damaging tissues
- Spectroscopy: THz radiation can provide novel information in chemistry and biochemistry.
- High altitude communication