All-optical modulation and photonic diode based on spatial self-phase modulation in porphyrin–napthalimide molecules

Abstract

Understanding the pathway of the interaction of matter and photon is essential for optoelectronic and photonic applications. Spatial self-phase modulation (SSPM) of light in materials through the Kerr effect has emerged as an intriguing and attractive research area owing to their outstanding light modulation, processing, and switching potentials. In this work, all-optical switching and modulation were achieved for four π-conjugated organic porphyrin samples using nonlinear optical (NLO) spatial self-phase modulation (SSPM) and cross-phase modulation (XPM) processes. The response time and sensitivity of all-optical modulators and switches were estimated of (0.15–0.32) s and (30.83–69.16) s⁻¹ using two-wavelength and mono-wavelength lasers in XPM geometry. An optical OR-logic gate was proposed using 440, 532, and 633 nm continuous wave (CW) lasers. Optical photonic diode is based on unidirectional SSPM diffraction ring patterns formed by the zinc porphyrin (Por-Zn)/halide double perovskite (Cs₂AgInCl₆) NC sample. These samples tested the all-optical signal transfer systems with 0.7 s and 1.1 s probe delay responses as compared to the pump signals, achieving the ASCII code for IITH ‘01001001010010010101010001001000’. The nonlinear refractive index and susceptibility of these materials were about (0.26–3.92) × 10⁻⁴ cm² W⁻¹ and (0.45–6.8) × 10⁻² esu. These findings suggest that the porphyrin samples could be used to create all-optical switches, modulators, and logic-gates for future optical and quantum technologies.