Abstract
This work studies the influence of an Erbium-Doped Fiber Amplifier (EDFA) on the phase variation of light in an optical fiber. To this end, the state of polarization (SOP) was measured as a function of optical power by adjusting the EDFA amplification, for two different laser output powers (2 dBm and 5 dBm). Results show that phase variation correlates with changes in optical power in both cases.

Abstract
Research on Programmable Electromagnetic Surfaces has gained considerable attention as an enabling technology for 6G communications, particularly at millimeter-wave and sub-THz bands. However, RISs face challenges related to the need for high-performance reconfigurable techniques that offer compact size and reduced power consumption at high frequencies. Moreover, the experimental characterization of unit cell performance using a waveguide remains a challenging issue. This paper discusses the design and performance analysis of a 1-bit reconfigurable unit cell at the Dband using non-volatile reconfigurable technology. The efficiency analysis of the unit cell was performed using periodic boundary conditions and waveguide configurations to mitigate simulation risks and validate the proposed design at the unit cell level. All simulation configurations confirmed an operational bandwidth of 25.65 GHz across the 147.8-173.45 GHz range, with a reflection loss of less than 1 dB and a phase difference within 180 degrees +/- 20 degrees.