Contents lists available at ScienceDirect Optik journal homepage: www.elsevier.com/locate/ijleo Original research article Characterization of microwave photoswitch integrating Metal- Semiconductor-Metal photodetector Abdel-Djawad Zebentout a,b, *, Amina Benzina a,b,c , Zouaoui Bensaad b , Hamza Abid b a Institute of Technology (IT), University Center of Ain Temouchent, 46000 Ain Temouchent, Algeria b Applied Materials Laboratory (AML), Research Center, Sidi Bel Abbes Djillali Liabes University, 22000 Sidi Bel Abbes, Algeria c Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia ARTICLE INFO Keywords: Microwave photoswitch Coplanar waveguide (CPW) GaAs Metal-Semiconductor-Metal (MSM) photodetector S-parameters On/Off ratio ABSTRACT An experimental study implemented to present the results of the characterization of microwave photoswitches to recognize the behavior of the microwave signals under laser light of 0.85 μm wavelength. These photoswitches consist of a coplanar line integrating a Schottky contact Metal- Semiconductor-Metal (MSM) photodetectors in the central line growth on GaAs Not Intentionally Doped (N.I.D). Those MSM photodetectors have a single electrode of different finger spacings (D) ranging from 0.2 μm to 1 μm and different finger widths (L) ranging from 0.2 μm to 5 μm. The characterizations of our optoelectronic devices made in the absence of illumination allowed us good isolation equal to -40 dB and under illumination insertion losses equal to -12.7 dB at 20 GHz. The obtained results are quite satisfying, have permitted to deduce the On/Off ratios and allowed to see the influence of the geometrical parameters on the transmission and reflection coefficients. 1. Introduction The coplanar waveguides are a type of planar transmission line used in microwave integrated circuits (MICs) as well as in monolithic microwave integrated circuits (MMICs) [1–4]. The unique feature of this transmission line designates that it is uniplanar in construction, which implies that all of the conductors are on the same side of the substrate. In this study, the Schottky contact Metal-Semiconductor-Metal (MSM) photodetector has a planar structure too [5,6] integrated into the central line of coplanar waveguide (CPW) to realize a microwave photoswitches on GaAs. For that, it has been proved that simple (photoconductor) metal-semiconductor-metal photoswitches (PSW) made from low-temperature-grown GaAs could be used [7]. In our case, the structure of the MSM photodetectors is not interdigitated as they are commonly used [8] but have a single- electrode structure. This single-electrode has different sizes; finger spacings (D) ranging from 0.2 μm to 1 μm and different finger widths (L) ranging from 0.2 μm to 5 μm. This writing describes the technological achievement and the structure of the microwave photoswitches (microwave photo- interrupters). Furthermore, a description of the microwave probe station system including the optical fiber. The characterizations were performed in the absence of illumination moreover under illumination (laser with continuous light emission) and the data of measurements as a function of frequency allowed us to see the variation of the S-parameters (reflection and transmission https://doi.org/10.1016/j.ijleo.2020.165226 Received 12 April 2020; Accepted 6 July 2020 ⁎ Corresponding author at: Institute of Technology (IT), University Center of Ain Temouchent, 46000 Ain Temouchent, Algeria. E-mail address: djawedz@yahoo.fr (A.-D. Zebentout). Optik - International Journal for Light and Electron Optics 220 (2020) 165226 0030-4026/ © 2020 Elsevier GmbH. All rights reserved. T