Polarization effects on heterodyne detection and imaging using Glow Discharge Detector at millimeter wavelengths Avihai Aharon (Akram)* 1,2 , Daniel Rozban 2,3 , Niv Banay 2 , A. Abramovich 2 , N. S. Kopeika 1,3 , Assaf Levanon 1 1 Department of Electrical & Computing Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel; 2 Department of Electrical and Electronic Engineering, Ariel University, Ariel, Israel; 3 Department of Electro-optical Engineering, Ben-Gurion University of the Negev, Beer- Sheva, Israel *Corresponding author: Avihaiak@gmail.com ABSTRACT A miniature neon indicator lamp, also known as a Glow Discharge Detector (GDD), costing about 50 cents, was found to be an excellent room temperature THz radiation detector. Polarization effects on heterodyne detection were investigated in this work. In heterodyne detection, because of the dot product relationship between signal electric field (E S ) and local oscillator (LO) electric field (E lo ), optimal operation of heterodyne detection is obtained when E S and E lo are of the same polarization. Preliminary results at 300 GHz showed better sensitivity by a factor of 20 with only 56 microwatt local oscillator power using heterodyne compared to direct detection. Further improvement of the detection sensitivity can be achieved if the LO power (P lo ) is increased. In this work investigation of polarization effects in heterodyne detection using neon indicator lamp GDD was carried-out. Experimental results of heterodyne detection at 300 GHz showed that an intermediate frequency (IF) signal was obtained for orthogonal polarization of the LO and signal, in contradiction to the theory. Also, our latest imaging results using Glow Discharge Detector at millimeter wavelengths will be shown in this work. Keywords: THz, Polarization, Heterodyne, THz detector, Plasma. 1. INTRODUCTION The interaction between microwave frequency and glow discharge tubes has been investigated theoretically and experimentally [1-4]. The use of Glow Discharge Detectors (GDDs) as electromagnetic radiation detectors is advantageous due to their wide dynamic range, electronic ruggedness, broad spectral range, room temperature operation, fast response time (less than a microsecond), simplicity of use, and very inexpensive cost (about 50 cents each) [3]. Investigations of GDD performance in the millimeter wavelength and THz radiation spectral regions were carried out recently and showed very good results [5, 6]. It was shown that the performances including Noise Equivalent Power (NEP) of GDD are similar to that of pyro-electric detectors, Golay cells and bolometers, but with orders of magnitude better response time [5]. Micro-bolometers with antennas are more sensitive, but are much more expensive and slower. The GDD was found to be of potentially better response and speed compared to schottky diode detectors [7]. The GDD has been used as a pixel in diffraction limited Focal Plane Arrays (FPA) [8], and in a single pixel imaging system in the MMW regime [9]. Heterodyne detection using GDDs was demonstrated at 10 GHz and found to be 40 times more sensitive compared to direct detection using very low local oscillator power [10]. Passive and Active Millimeter-Wave Imaging XVII, edited by David A. Wikner, Arttu R. Luukanen, Proc. of SPIE Vol. 9078, 90780F · © 2014 SPIE CCC code: 0277-786X/14/$18 · doi: 10.1117/12.2053175 Proc. of SPIE Vol. 9078 90780F-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 03/15/2015 Terms of Use: http://spiedl.org/terms