Room-temperature terahertz quantum cascade lasers

This breakthrough in THz generation is a development the THz research field has been seeking for years. Whether it is due to high costs, square footage required, or the need for professionals trained to handle cryogenic coolants, cooling has limited the implementation of THz sources and detectors in many applications. For example, the cooling equipment’s size and weight, and the added weight of the coolant itself, have prevented THz techniques from being employed in space-based measurements. The THz QCL, despite this limitation, has excelled in continuous-wavelength coveragecomparedtocompetitivetechnolo-gies. In overcoming this cooling limitation, the THz NL-QCL becomes a more viable option for low-frequency THz generation at room temperature. Not only is it compact and mass-producible, but it is also more user-friendly in optical design, it is more convenient to integrate into existing setups, and it showcases higher performance than existing THz QCLs. However, more must be done if this device is to become highly sought after — especially for applications such as material analysis, wireless communications, trace gas analysis, medical imaging, and identification of pharmaceutical raw materials. In addition to improving room-temperature operability, output powers must be increased. To do so, Hamamatsu Photonics plans to further improve the QCL structure’s design to obtain continuous-wave operation with constant light output intensity. © 2020, Laurin Publishing Co. Inc.. All rights reserved.