Current state and prospects of detectors in the terahertz range Part 1. Direct detection of terahertz radiation

The paper discusses the problems associated with the development of technology for terahertz radiation detectors. The main physical phenomena and recent pro-gress in various methods of detecting terahertz radiation (direct detection and het-erodyne detection) are considered. Advantages and disadvantages of direct detec-tion sensors and sensors with heterodyne detection are discussed. In part 1, a number of features of direct detection are considered and some types of terahertz direct detection detectors are described. Part 2 will describe heterodyne detection and continue to describe some types of modern photonic terahertz receivers.