Abstract: We report and demonstrate an electronic circuit analogue of superluminal and subluminal phenomena whose Group Delay covers both the negative and positive range in a tunable manner but uses only a simple operational amplifier (Op-Amp) circuit. The circuit is a modified version of Kitano and Nakanishi's Negative Group Delay Circuit which covers only the negative group delay signal. By adding a simple low-pass RC circuit at the output of the Op-Amp, we can generate a continuous, tunable group delay range by simply varying the value of the capacitance of the circuit. We show mathematically and experimentally the following: (i) temporally advanced (negative group delay) signal, (ii) no-group delay signal, and (iii) typical delayed (retraction or lagged time) signal over a very narrow bandwidth as a demonstration of the circuit analogue of the superluminal and subluminal phenomena.

Abstract: We propose two hybrid configurations that mixed some aspects of a standard double ring resonator (SDR) and a recently proposed cross-coupled double ring resonator (CC-SDR). The SDR is a well-established component of photonic integrated circuits consisting of two microrings that are serially connected by two standard direct-coupled directional couplers (DCs). On the other hand, a CC-SDR is similar to SDR except the interconnections are done with two cross-coupled DCs. Here, the hybrid configurations are implemented with one direct-coupling DC and one cross-coupling DC, instead of the typical two direct-coupling DCs or two cross-coupling DCs. Furthermore, we report that one of the hybrid-double resonator configurations exhibits a new behavior, called shifted coupled resonator induced transparency property.

Abstract: We propose a simple and yet effective compensation technique to address the potential back-reflected signal coming from the output port of the minimalist-designed, linear optical field frequency discriminator (FD) having a unique folded-back arrangement. Specifically, we consider the engineering problems associated with the combined effects of (i) back reflection signal coming from the output port of the Y-junction divider, and (ii) non-optimized coupling condition of the Y-junction power divider. Our proposed compensation technique solves these problems by using a reflector (or mirror) with variable reflectance positioned at one of the outputs of the single Mach-Zehnder interferometer (MZI) device. By tuning the value of the mirror reflectance to an optimal value, we can compensate for the effects of these above-mentioned problems.

Abstract: We present a comprehensive parameters sensitivity analysis of the minimalist-design frequency discriminator, FD filter involving three parameters namely, (i) the back reflection coefficient “ b ”, (ii) mirror reflectance “ a ”, and (iii) the split-power ratio of the Y-combiner “ r ”. We demonstrated that the measured linearity (bandwidth utilization, BWU and Normalized Deviation, ND) are negatively impacted by the increase in parameters b and r, but can be compensated by decreasing the value of the mirror reflectivity “ a ”.

Abstract: Previously, we reported a simple, low-cost, thin–film–based optical analogue of the Thomas Effect in Special Relativity (SR) using an ideal Michelson-Gires-Tournois interferometer (MGTI). This opens the door for other SR related phenomena to be studied analogously. Toward this goal, there are two important tasks. First, it is imperative to conduct a comprehensive evaluation of the technical limitations of this platform under two non-ideal (oftentimes unavoidable) operating conditions, namely: (i) an imperfect Gires-Tournois resonator (GTR), and (ii) the presence of interferometric error due to mismatch in the path-length arm difference of the MGTI. Second, it is also important to develop a technique to recover the direction information of the Thomas angle which is lost during the intensity measurement ...