System reducing fiber stretch induced timing errors in fiber optic coupled time domain terahertz systems

摘要

A system (10d) for reducing effects relating to stretching of an optical fiber (71 d), the system comprising: an optical source (12d), the optical source (12d) outputting an optical signal; a terahertz transmitter (14d) optically coupled to the optical source (12d), the terahertz transmitter (14d) configured to emit terahertz radiation to a sample (30d) when activated by the optical signal; a terahertz receiver (15d) optically coupled to the optical source (12d), the terahertz receiver (15d) configured to detect terahertz radiation conditioned by the sample (30d) and generate an electrical signal which can be interpreted, scaled and/or digitized by a data acquisition system (17d) electrically coupled to the terahertz receiver (15d); a means (16d) for providing the optical signal to both the terahertz transmitter (14d) and terahertz receiver (15d) such that the terahertz receiver (15d) is synchronized to the terahertz transmitter (14d) by the optical signal; and wherein the means (16d) allows for the stretching of the optical fiber (71 d) carrying the optical signal provided to the terahertz transmitter (14d) and terahertz receiver (15d) such that the terahertz receiver (15d) is synchronized to the terahertz transmitter (14d) by the optical signal, wherein the means (16d) comprises a multiplexer (70d) optically coupled to the optical source (12d); the optical fiber (71 d), wherein the optical fiber (71 d) is optically coupled to the multiplexer (70d) and wherein the optical fiber (71 d) has a single core (74d); wherein the multiplexer (70d) is configured to provide a first pulse based on the optical signal to the optical fiber (71 d); wherein the multiplexer (70d) is configured to provide a second pulse based on the optical signal to the optical fiber (71 d); wherein the first pulse and second pulse are orthogonal to each other as they travel through the optical fiber (71 d); and a demultiplexer (72d) optically coupled to the optical fiber (71 d), the demultiplexer (72d) configured to receive the first and second pulse and provide the first pulse to the terahertz transmitter (14d) and the second pulse the terahertz receiver (15d).