Showing papers on "Terahertz radiation published in 1974"
TL;DR: Schottky diodes have been used for the first time as harmonic mixers in the 0.1-1.0mm wavelength region as discussed by the authors, where the beat notes between the 33rd harmonic of a 74 GHz V-band klystron and 118.8μ laser radiation are observed directly without the need of narrow-band synchronous detection.
Abstract: Schottky diodes have been used for the first time as harmonic mixers in the 0.1–1.0‐mm wavelength region. Beat notes between the 33rd harmonic of a 74‐GHz V‐band klystron and 118.8‐μ laser radiation are observed directly without the need of narrow‐band synchronous detection. The demonstrated performance of these room‐temperature diodes as wide‐band or heterodyne detectors of submillimeter radiation and their rugged construction make them superior to current point contact devices.
78 citations
TL;DR: In this paper, the authors analyzed the interaction of a high-frequency electromagnetic pump wave with a magnetized plasma and found enhanced growth rates for parametric instability near cyclotron resonance.
Abstract: Interaction of a high‐frequency electromagnetic pump wave with a magnetized plasma is analyzed. Enhanced growth rates for parametric instability are found near cyclotron resonance. The result implies that tunable high‐power submillimeter sources could be developed using intense relativistic electron beams.
50 citations
TL;DR: In this paper, a relativistic electron beam at submillimeter wavelengths has been measured with bandpass and high-pass filters with a power ∼ 100 kW in the passband 390 μm −540 μm.
Abstract: Radiation from an intense relativistic electron beam at submillimeter wavelengths has been measured with bandpass and high-pass filters. Radiated power ∼ 100 kW has been measured in the passband 390 μm −540 μm. The generation of this radiation depends on giving the electrons a large energy component transverse to the magnetic guide field. Coherent wave generation mechanisms which may account for the observed radiation are discussed.
40 citations
TL;DR: In this article, a summary of recent developments in dispersive Fourier transform techniques for the measurement of the frequency variation of the complex refractive index in the range 100 GHz-9 THz is given.
Abstract: A summary is given of recent developments in dispersive Fourier transform techniques for the measurement of the frequency variation of the complex refractive index in the range 100 GHz-9 THz. Progress in overcoming the special problems associated with liquid and solid specimens of medium and strong absorption is reported and the current measurement capability is discussed with the aid of experimental results obtained using specially constructed equipment.
18 citations
TL;DR: In this paper, high-power submillimeter (H-SML) LIDAR was used for important diagnostic measurements in Tokamak plasmas, such as the determination of ion temperature by Thomson scattering and the measurement of transverse thermal conductivity by resonant local heating.
Abstract: Recent advances in the development of high power submillimeter lasers have opened up new areas of investigation in the study of laser plasma interactions. These areas include studies of laser-induced gas breakdown and plasma heating at cyclotron resonance, laser-induced breakdown effects in solids, and studies of Iaser-generated parametric instabilities in arc plasmas. In addition, high power submillimeter lasers can be used for important diagnostic measurements in Tokamak plasmas. These measurements include the determination of ion temperature by Thomson scattering and the measurement of transverse thermal conductivity by resonant local heating.
13 citations
TL;DR: In this article, the stimulated emission from formic acid molecules was observed for the first time in the submillimeter range, and the pumping source was a frequency-tunable CO2 laser.
Abstract: The stimulated emission from formic acid molecules was observed for the first time in the submillimeter range. The pumping source was a frequency-tunable CO2 laser. The cw power of the submillimeter radiation ranged from tens of microwatts to several milliwatts when the pumping power was up to 7 W. The stimulated emission was observed at 22 wavelengths ranging from 250 to 750 μ.
8 citations
TL;DR: A new absorption line of CH3OH vapor, which coincided with the R(38) line of the 0001-1000 band of the CO2 laser, was detected and investigated in the course of a study of an optically pumped CH 3OH laser as mentioned in this paper.
Abstract: A new absorption line of the CH3OH vapor, which coincided with the R(38) line of the 0001–1000 band of the CO2 laser, was detected and investigated in the course of a study of an optically pumped CH3OH laser. The absorption coefficient was 0.1 cm–1 torr–1. Pumping with the R(38) line produced submillimeter radiation of wavelengths 164, 246, and 470 μ and of output power 0.1–1 mW.
7 citations
01 Jan 1974
4 citations
TL;DR: In this article, the optimal characteristics of amplitude splitters for submillimeter radiation beams are determined for optical schemes with large light gathering power (LGP) utilizing such splitters.
Abstract: The optimal characteristics of amplitude splitters for submillimeter radiation beams are determined. Versions of optical schemes with large light gathering power (LGP) utilizing such splitters are proposed. Using them, high sensitivity receiving devices for the 2-0.2-mm waveband region with Fabry-Perot interferometers (FPI) and Michelson interferometers (MI) and n-InSb immersion detectors (spectroradiometers) are constructed.
4 citations
1 citations
01 Jun 1974
TL;DR: In this paper, the scattering and extinction properties of cloud and rain elements for far-infrared and sub-millimeter radiation have been estimated on the basis of recently determined optical constants, by means of polydisperse Mie scattering theory and realistic drop-size distributions.
Abstract: The scattering and extinction properties of cloud and rain elements for far-infrared and submillimeter radiation have been estimated on the basis of recently determined optical constants, by means of polydisperse Mie scattering theory and realistic drop-size distributions.