This article discusses the performance of the free space optics (FSO) systems for short-range applications with the input signal power optimization. The BER eye diagram analyzer used to compute the optimum bit error rate and also compute the maximum Q factor for the previous and proposed models. The previous model has outlined the maximum Q factor of 206.45, where the proposed model Q factor value is 569.867 under the same operating parameters such as the wavelength of the transmitter of 1550 nm, the power of the transmitter of 10 mW, and the range of FSO is 800 m and signal attenuation 0.4 dB/km. The proposed study has outlined better performance than the previous study by about 21.76% enhancement percentage ratio.

This paper contains a main model which concludes a two optical fiber cable along 70 km and with Parametric/Raman amplifiers with a result of total power 0.781 dBm that computed by the optical power meter which is located before the receiver part and the second optical fiber channel, a total power −44.186 dBm at the end of model which is computed by the electrical power meter visualizer, and a max. Q factor 2.548 computed by the BER analyzer. The suggested model has outlined some updates on the previous model to improve the results so that the results are increased at the same length as the following: total power of optical signal becomes 10.039 dBm, total power of electrical signal becomes 0.624 dBm, and the max. Q factor becomes 9.60787.

This work has reported the optical switches based semiconductor optical amplifiers (SOAs) for the performance of the characteristics enhancement by using various electrical pulse generators. Max. Q, bit error rate (BER) after light detector, max. signal power (MSP), min. noise power (MNNP), and total optical power after power combiner based SOAs with various pulse generators are simulated and clarified. Return to zero (RZ) pulse code has clarified max Q than other pulse generators. The max output signal power is improved with Gaussian pulse in compared to other pulse generators. Triangle/RZ pulse generators have presented better total optical power than other proposed generators.

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Objective To differentiate healthy from artificially degraded articular cartilage and estimate its structural, compositional, and functional properties using Raman spectroscopy (RS). Design Visually normal bovine patellae (n = 12) were used in this study. Osteochondral plugs (n = 60) were prepared and artificially degraded either enzymatically (via Collagenase D or Trypsin) or mechanically (via impact loading or surface abrasion) to induce mild to severe cartilage damage; additionally, control plugs were prepared (n = 12). Raman spectra were acquired from the samples before and after artificial degradation. Afterwards, reference biomechanical properties, proteoglycan (PG) content, collagen orientation, and zonal (%) thickness of the samples were measured. Machine learning models (classifiers and regressors) were then developed to discriminate healthy from degraded cartilage based on their Raman spectra and to predict the aforementioned reference properties. Results The classifiers accurately categorized healthy and degraded samples (accuracy = 86%), and successfully discerned moderate from severely degraded samples (accuracy = 90%). On the other hand, the regression models estimated cartilage biomechanical properties with reasonable error (≤ 24%), with the lowest error observed in the prediction of instantaneous modulus (12%). With zonal properties, the lowest prediction errors were observed in the deep zone, i.e., PG content (14%), collagen orientation (29%), and zonal thickness (9%). Conclusion RS is capable of discriminating between healthy and damaged cartilage, and can estimate tissue properties with reasonable errors. These findings demonstrate the clinical potential of RS.