Fully-coherent terahertz detection method and system (market study)

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The current proposal is concerned with a market study related to the development of a fully coherent heterodyne detection system at Terahertz (THz) frequencies and in particular, with the use of centro-symmetric materials for THz detection. The main detection method commonly used in THz science and named Air Biased Coherent Detection (ABCD), is based on the Terahertz Field Induced Second Harmonics (TFISH) technique, and allows to record THz fields with extremely large bandwidth (>20 THz). The system is composed of a pair of electrodes suspended in air and separated by a distance close to 1 millimeter, which correspond to the section where THz and optical beams are focused. In this region an intense AC external bias is applied to the optical focus in order to generate a bias field and to induce a second harmonic pulse. The higher the external bias, the better the signal. Unfortunately miniaturization and integration remain elusive. Not only the existing systems cannot be easily miniaturized (dimension of few cm or less) but current detection set-ups require the use of high voltage amplifiers (typically kV sources) thus affecting the accessibility to this technique. Moreover, since the detection occurs in air, the use of high voltage is limited by air breakdown. Here we propose to overcome these limitations by employing metallic slits with a gap width of few tens of micron and filled with a nonlinear, high breakdown voltage medium, in this case SiO2. The slits are then biased with an external voltage source in order to apply the concept of ABCD to the layer of nonlinear material that is deposited between the electrodes. The advantages of this idea consists in the ability to readily solve the problems encountered in the current detection systems i.e. the need of a strong applied voltage, a poor signal to noise ratio, as well as the need to use intense pulses at 800 nm. The simplicity of this concept may as well lead to the cost performance and mass-reproducible characteristics that are prerequisite to successful commercialization, hence we strongly believe that a market study for this innovative technology is extremely timely and will contribute to reinforce the impact of the Canadian THz Industry on the international scene.