Ultrafast optical switching using parity–time symmetric Bragg gratings

Abstract

Received Month X, XXXX; revised Month X, XXXX; accepted Month X, XXXX; posted Month X, XXXX (Doc. ID XXXXX); published Month X, XXXX This paper reports on time-domain modeling of an optical switch based on the PT-Symmetric Bragg grating. The switching response is triggered by suddenly switching on the gain in the Bragg grating to create a PT-Symmetric Bragg grating. Transient and dynamic behavior of the PT Bragg gratings is analyzed using the time-domain numerical Transmission Line Modeling (TLM) method including a simple gain saturation model. The on/off ratio and the switching time of the PT-Bragg grating optical switch are analyzed in terms of the level of gain introduced in the system and the operating frequency. The paper also discusses the effect the gain saturation has on the operation of the PT-Symmetric Bragg gratings.

Switching of the direction of reflectionless light propagation at exceptional points in non-PT-symmetric structures using phase-change materials

“…1). The optical properties of our proposed system can be described by the scattering matrix S defined by the following equation [14,16,17,20,[46][47][48] Fig. 1.…”

Threshold manipulation in parity-time symmetric microresonator chain

“…The odd symmetry of the imaginary refractive index results in structures that have both gain and loss. Interestingly, despite the presence of gain and loss, PT-symmetric structures feature a zero-net power gain or loss if operated before a threshold point, whilst power grows exponentially beyond this threshold point [4]. In lossless structures the eigenfrequencies below the threshold point are purely real, whilst above the threshold point they become complex conjugates indicating the presence of both gain and loss modes.…”

Electro-thermal modelling for plasmonic structures in the TLM method

“…Dispersive and frequency dependent properties are implemented using digital filters methodology (Paul 1998). Traditionally TLM has been used for microwave applications but it has also proved useful at optical frequencies (Janyani et al 2004;Meng et al 2013;Phang et al 2013) The electromagnetic properties of plasma and a range of plasmonic devices such as a Surface Plasmon Polariton Waveguide Bragg Grating (SPP-WBG) and a dielectric surface grating for beam focusing applications have also been modelled in the TLM using the digital filter approach (Ahmed et al 2010;Paul et al 1999).…”