Journal of Nonlinear Optical Physics & Materials

Since the discovery of lasers, high-quality nonlinear optical (NLO) single crystals have served as the foundation for the creation of novel, cutting-edge devices that meet societal demands. Modern optoelectronic applications such as telecommunication lasers, optical fibers, photodiodes, solar cells, etc. favor high-performance nonlinear optical single crystals with improved optical nonlinearity. Organic crystals are extensively explored for these applications because of their high NLO coefficient. This paper deals with the problems and advancements of organic nonlinear optical single crystals. Here, we review the growth and characterizations of various tosylate family crystals from the vast realm of organic single crystals and their potential applications in the field of optoelectronic devices. Various properties like linear and nonlinear optical, thermal, mechanical, and laser damage threshold values for these samples have been summarized. The attempts are made for highlighting how these tosylate (p-Toluenesulfonic acid based) family crystals can be realized into efficient optoelectronic devices by summarizing variously reported cut-off wavelengths and their wide transmission ranges.

Frequency encoded reconfigurable logic gates OR and AND are designed using interferometric switch based on quantum dot semiconductor optical amplifier (QDSOA) and simulated using MATLAB for the first time as far as our knowledge goes. The amplitude modulation (AM) and quality factor ($Q_{\mathrm{\text{fe}}})$ are calculated using numerical simulations confirming practical feasibility of the logic gates. This paper also investigates the effect of amplified spontaneous emission (ASE) noise on AM, $Q_{\mathrm{\text{fe}}}$ and signal-to-noise ratio (SNR) values. AM below 0.005 dB and $Q_{\mathrm{\text{fe}}}$ more than 30dB ensure error free operation of the logic gates.

Domain randomness is inherent in the fabrication of periodically poled lithium niobate (PPLN). The main cause of such domain randomness in fabrication of PPLN is due to electric poling process. This domain randomness not only impacts the effectiveness of frequency conversion, but also enhances the effectiveness of nonphase matched parasitic processes, which in many cases limits the performance of the device. In this paper, we experimentally demonstrate a nondestructive characterization of domain randomness in PPLN by diffraction-noise pattern with uniform illumination. We measure the domain randomness of PPLN and provide an effective method for poling quality assessment either as good or poor quality of PPLN through this paper.

The work is devoted to the study of the second-harmonic generation (SHG) process as a result of random quasi-phase-matching of thulium laser radiation in ZnSe polycrystals. A linear dependence of the SHG efficiency on the nonlinear medium length has been observed in the experiment. The efficiencies of SHG in ZnSe polycrystals with average grain sizes from 35$\mu$m to 380$\mu$m were compared. The obtained results are in good agreement with the theory in the case of a Gaussian grain size distribution.

Wavelength division multiplexing (WDM) is one of the emerging technologies for data transmission in 5G access network assembly between the antenna unit (AU) and the distribution unit (DU). Here, in this work, we evaluate and analyze a dense wavelength division multiplexing (DWDM) — passive optical networks (PONs) employing erbium–ytterbium-doped fiber amplifier (EYDFA) $+$ Raman hybrid optical amplifier (HOA) using two modulation schemes — modified duobinary return to zero (MDRZ) and differential phase shift keying (DPSK) for alternate channels, where the channel count has been varied from 8 to 40. The system has been analyzed over the wavelength span of 1550–1558.8nm with a channel spacing, input power and data rate of 25GHz, 0dB and 40Gb/s, respectively. An average gain, gain ripple and optical signal-to-noise ratio (OSNR) of 20.87, 0.95 and 30dB, respectively have been observed in the case of HOA along with the achievement of Q-factor of up to 9 at the receiving end of the system. The DPSK-modulated channels result in higher values of gain and OSNR along with lower gain ripple as compared to MDRZ channels making the proposed system a good option for 5G access network applications.

In nonlinear Schrödinger equations (NLSEs), the third-order generalized NLSE is a significant sculpture which is utilized for modeling ultrashort pulses in fiber optics. In this study, we obtained wave and soliton solutions by using new extended and modified Rational expansion method to get several types of soliton such as bright solitons, dark solitons, perodic solitons and traveling waves. In three-dimensional and two-dimensional plots, we present graphical representations in dissimilar structures of some solutions to understand the phenomena physically. The development and achievements of computing show the power and effectiveness of current technology. In addition, we are able to resolve various other high-order NLSEs with the assistance of effortless and effectual technique.

In this paper, we examine generalized nonlinear Schrödinger equation (GNLSE) for lump, breather lump wave, rogue wave, periodic cross kink wave, lump with one kink, lump with two kink, interaction between lump periodic and kink wave, periodic cross lump wave, periodic wave, and multiwave. Ansatz transformations will be used to study homoclinic breather, kink cross rational, M-shaped rational, periodic cross rational, M-shaped rational with one kink, M-shaped rational with two kink, M-shaped interaction with rogue and kink and M-shaped interaction with periodic and kink. We will also study the stability of the obtained solutions. Additionally, we present 3D, 2D, contour, and stream plot illustrations for our graphs.

We investigate theoretically an optomechanical system composed of an optical mode and a mechanical mode interacting through first-order coupling and second-order coupling in the presence of a Kerr nonlinear medium. We study how the nonlinearities (second-order optomechanical coupling and Kerr nonlinearity) alter the optical output spectrum, optical quadrature squeezing and optomechanical entanglement. It is shown that the intensity of the output optical spectrum decreases drastically with an increase in second-order optomechanical coupling while it increases significantly with an increase in Kerr nonlinear parameter. More interestingly, by choosing suitable second-order optomechanical coupling and detuning of the optical cavity field, one can achieve strong squeezing of the cavity light field. Further, these nonlinearities play an important role in creating robust optomechanical entanglement between optical and mechanical modes. Hence, the presence of various nonlinearities in the system can be a good platform for achieving the squeezing of light and robust optomechanical entanglement which can be used in realizing better quantum optomechanical devices.