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Quaternary glass series of nano and micro-particles europium oxide (III), i.e. Eu2O3,of composition [{(TeO2)0.7(B2O3)0.3}0.7(ZnO)0.3](1-y)(EnOm)y, where EnOmis nano or micro Eu2O3particles coded as TBZEu-NPs and TBZEu-MPs with y = 1.0–5.0 mol% was prepared by melt-quenching technique. Using the pulse-echo technique, the ultrasonic velocities of the glasses were examined. The experimental value of TBZEu-NPs longitudinal, shear, bulk, and Young's modulus ranges between 53.469 and 85.259 GPa, 21.801–24.086 GPa, 24.401–54.790 GPa, and 50.394–61.419 GPa, respectively. For the TBZEu-MPs glasses, they ranged from 46.335 to 87.365 GPa, 21.645–24.649 GPa, 17.475–54.499 GPa, and 45.959–64.260 GPa, respectively. Density and elastic properties were predicted and simulated using an artificial neural network (ANN) model. The correlation coefficients for density, elastic moduli, and Poison's ratio obtained using the ANN model range from 0.9881 to 0.9997. The fitted R-squared value is greater than 95%, and the percentage error calculated is less than 7%. The obtained results were compared to those obtained using the Makishima-Mackenzie elastic model. The prepared glass sample's physical properties and elastic constants indicate that they are sufficiently strong for laser applications.

A Q-switched fibre laser operating at 1500 nm is proposed and demonstrated. The laser uses a saturable absorber (SA) based on carbon nanotubes (CNTs) to generate Q-switched pulses, while a 30-m-long depressed-cladding erbium-doped fibre (DC-EDF) provides the necessary gain in the desired wavelength region. The proposed laser has lasing and pulsed thresholds of 30 mW and 50 mW respectively, along with a maximum output power, pulse energy and peak power of 0.5 mW, 7.6 nJ and 2.2 mW. Additionally, the output of the system also has a maximum repetition rate of 59.4 kHz with the shortest pulse duration measured at 3.4 μs. The output pulses are smooth and uniform, with no indication of self mode-locking.

We propose and demonstrate a wide-band semiconductor optical amplifier (SOA) based triple-wavelength superluminescent source with the output in the S-, C- and L-band regions. The proposed systems uses an ultra-wideband SOA with an amplification range from 1440 to as the linear gain medium. Three fibre Bragg gratings (FBGs) with centre wavelengths of 1500, 1540 and are used to generate the lasing wavelengths in the S-, C- and L-bands respectively, while a variable optical attenuator is used to finely balance the optical powers of the lasing wavelengths. The ultra-wideband SOA generates an amplified spontaneous emission (ASE) spectrum with a peak power of at the highest SOA drive current, and also demonstrates a down-shift in the centre wavelength of the generated spectrum due to the spatial distribution of the carrier densities. The S-band wavelength is the dominant wavelength at high drive currents, with an output power of as compared to the C- and L-bands, which only have powers of and , respectively. All wavelengths have a high average signal-to-noise ratio more than at the highest drive current of , and the system also shows a high degree of stability, with power fluctuations of less than within . The proposed system can find many applications where a wide-band and stable laser source is crucial, such as in communications and sensing.