THz metrology for active electronic devices: state of the art and challenges

The area of terahertz science and applications has grown dramatically in the last 30 years. Instrumental platforms for THz measurements have also proliferated, and now include laser-based, electronic, opto-electronic, and microwave photonics devices. As the field matured, metrology and standardization have gained focused attention, resulting in an increasing number of publications and a book devoted to the subject. However, these have been primarily focused on photonic-based free-space techniques and their particular demands and issues. This paper presents a brief review of metrology requirements for active THz electronic devices, the available instrumentation, state of the art, and challenges.