A Simple Interferometer for the Analysis of Terahertz Sources and Detectors

Building an end user focused THz based ultra high bandwidth wireless access network: The TERAPOD approach

“…The beam divergence will also be measured, and the power density as a function of distance from the emitter will be calculated. A customdesigned lamellar interferometer [27] with broadband response (0.1-10 THz) and high frequency resolution 0.3 GHz will be used in conjunctions with a calibrated power meter to determine the power spectral density of the emitted radiation, with particular attention to the possible presence of sidebands or higher harmonics and their effect on the fundamental signal. Spectral responsivity of THz receivers will likewise be measured using the interferometer and a power-calibrated broadband source.…”

A simple Fourier transform spectrometer for terahertz applications

“…There are several types of FTS; for example, the lamellar grating interferometer [3], Martin-Puplett interferometer [4], low-reflectivity Fabry-Perot interferometer [5] (where the low-reflectivity etalon means that the interferogram is similar to that of the Michelson interferometer) and Michelson interferometer [6]. We use a Michelson interferometer for its simplicity and compactness.…”

“…We studied the properties of heterodyne detectors including superconductor mixers and semiconductor harmonic mixers, direct detectors including an InSb semiconductor bolometer, superconducting tunnel junctions and the Golay cell, and sources including Gunn oscillators and a microwave source with its multipliers, as well as various materials and passive devices including Si wafers and metal mesh filters. Because of its multiplex and etendue advantages, Fourier transform spectroscopy has become the most efficient way to evaluate the properties of signal sources, samples and detectors in the terahertz (THz) range [1][2][3]. The multiplex advantage is that the interferometer receives information from the entire range of a given spectrum during each time element of a scan, whereas a grating spectrometer receives information from only a narrow band of the spectrum.…”

“…Because of its multiplex and etendue advantages, Fourier transform spectroscopy has become the most efficient way to evaluate the properties of signal sources, samples and detectors in the terahertz (THz) range [1][2][3]. The multiplex advantage is that the interferometer receives information from the entire range of a given spectrum during each time element of a scan, whereas a grating spectrometer receives information from only a narrow band of the spectrum.…”

Semiconductor optical amplifier-based heterodyning detection for resolving optical terahertz beat-tone signals from passively mode-locked semiconductor lasers

“…Detection and characterization of broad-band light sources ͑either pulsed or continuous wave͒ in the sub-THz regime and beyond is usually achieved by using bolometers, Golay cells and pyroelectric detectors. 1,2 It has also been proposed to analyze the rf spectrum of light sources by means of optical techniques such as nonlinear interactions in highly nonlinear fibers 3 and cross-phase modulation in nonlinear waveguides. 4 In spite of the great achievements accomplished in the majority of the mentioned schemes in terms of frequency resolution ͑in the order of GHz͒ and bandwidth ͑from 100 GHz to few THz͒, their main difficulties are the necessity of large experimental setups and the cost of the utilized components.…”