Time dependent capacitance in Photoconductive Antenna
01 Dec 2015-pp 1-2
TL;DR: In this article, the capacitance analysis of a pulsed photoconductive antenna (PCA) system was performed to provide a better understanding of carrier dynamics in PCA and also helps in creating an accurate equivalent electrical circuit of PCA.
Abstract: Photoconductive Antenna(PCA) is considered to be very simple and compact Terahertz (THz) generation source based on opto-electrical conversion method. In recent years, several experimental and simulation studies have been performed to analyze a PCA behavior. However, an accurate equivalent electrical circuit model is needed for theoretical analysis of a PCA. As the electrode gap region of PCA can be modeled as a charged capacitor, this work deals with the calculation of time dependent capacitance of a pulsed PCA system. The analysis of time dependent capacitance provides a better understanding of carrier dynamics in PCA and also helps in creating an accurate equivalent electrical circuit of PCA.
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TL;DR: In this article, the authors presented an equivalent electrical circuit model of PCA incorporating basic semiconductor device physics, which is validated using Sentaurus TCAD device level modeling tool as well as with the experimental results available in the literature.
23 citations
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01 Apr 2017
TL;DR: In this paper, an effort has been made to analyze the performance of a photoconductive antenna as a receiver by modeling an equivalent electrical circuit of it, which is based on the physics involved in its operation.
Abstract: Photoconductive antenna (PCA), due to its simple and compact structure, is emerging in recent times as a popular device for generation of Terahertz (THz) frequencies. The working of PCA is based on the optical-to-electrical power conversion technique. The main advantage of the PCA is that it can be used both as a source as well as a detector with little changes in the operating mechanism. In literature, several experimental, simulation and theoretical studied are available for PCA operating as a source. However, very few experimental and simulation studies are available to analyze the performance of PCA as a receiver. In this communication, an effort has been made to analyze the performance of a PCA as a receiver by modeling an equivalent electrical circuit of it, which is based on the physics involved in its operation.
1 citations
Cites methods from "Time dependent capacitance in Photo..."
...Using the procedure as reported in [16], the current through the capacitance is written as,...
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References
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TL;DR: This paper describes a robust algorithm for extracting material parameters from measured terahertz waveforms that simultaneously obtains both the thickness and the complex refractive index of an unknown sample under certain conditions.
Abstract: Imaging systems based on terahertz (THz) time-domain spectroscopy offer a range of unique modalities owing to the broad bandwidth, subpicosecond duration, and phase-sensitive detection of the THz pulses. Furthermore, the possibility exists for combining spectroscopic characterization or identification with imaging because the radiation is broadband in nature. To achieve this, we require novel methods for real-time analysis of THz waveforms. This paper describes a robust algorithm for extracting material parameters from measured THz waveforms. Our algorithm simultaneously obtains both the thickness and the complex refractive index of an unknown sample under certain conditions. In contrast, most spectroscopic transmission measurements require knowledge of the sample's thickness for an accurate determination of its optical parameters. Our approach relies on a model-based estimation, a gradient descent search, and the total variation measure. We explore the limits of this technique and compare the results with literature data for optical parameters of several different materials.
676 citations
01 Oct 2007
TL;DR: Terahertz (THz) radiation, which occupies a relatively unexplored portion of the electromagnetic spectrum between the mid-infrared and microwave bands, offers innovative sensing and imaging technologies that can provide information unavailable through conventional methods such as microwave and X-ray as discussed by the authors.
Abstract: Terahertz (THz) radiation, which occupies a relatively unexplored portion of the electromagnetic spectrum between the mid-infrared and microwave bands, offers innovative sensing and imaging technologies that can provide information unavailable through conventional methods such as microwave and X-ray techniques. With the advancement of THz technologies, THz sensing and imaging will impact a broad range of interdisciplinary fields, including chemical and biological detections and identifications. In particular, THz radiation offers the opportunity for transformational advances in defense and security. Recent work shows that THz technologies are promising for the standoff detection and identification of explosive targets.
479 citations
01 Jan 2007
TL;DR: THz technologies are promising for the standoff detection and identification of explosive targets and the opportunity for transformational advances in defense and security is offered.
Abstract: Terahertz (THz) radiation, which occupies a relatively unexplored portion of the electromagnetic spectrum between the mid-infrared and microwave bands, offers inno- vative sensing and imaging technologies that can provide information unavailable through conventional methods such as microwave and X-ray techniques. With the advancement of THz technologies, THz sensing and imaging will impact a broad range of interdisciplinary fields, including chemical and biological detections and identifications. In particular, THz radiation offers the opportunity for transformational advances in defense and security. Recent work shows that THz technol- ogies are promising for the standoff detection and identifica- tion of explosive targets.
427 citations
TL;DR: In this article, the authors reviewed the most recent results in terahertz fields and focused on the physical principles of tera-hertz generators and receivers, underlining the link between terahethertz devices and modern technologies such as micromachining and nanotechnology.
405 citations
"Time dependent capacitance in Photo..." refers background in this paper
...THz frequency band is situated between microwave and optical frequency bands ranges from 100GHz to 10THz [1]....
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...THz radiation can be generated by various sources such as gyrotrons [5], free electron lasers [6], photo-mixing , photoconductive antenna [1] etc....
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TL;DR: To cover a so-called terahertz gap in available sources of coherent electromagnetic radiation, the gyrotron with a pulsed solenoid producing up to a 40 T magnetic field has been designed, manufactured, and tested.
Abstract: To cover a so-called terahertz gap in available sources of coherent electromagnetic radiation, the gyrotron with a pulsed solenoid producing up to a 40 T magnetic field has been designed, manufactured, and tested. At a 38.5 T magnetic field, the gyrotron generated coherent radiation at 1.022 THz frequency in 50 musec pulses. The microwave power and energy per pulse were about 1.5 kW and 75 mJ, respectively. Details of the gyrotron design, manufacturing, operation and measurements of output radiation are given.
310 citations
"Time dependent capacitance in Photo..." refers background in this paper
...THz radiation can be generated by various sources such as gyrotrons [5], free electron lasers [6], photo-mixing , photoconductive antenna [1] etc....
[...]