High performance Raman amplifier: applications in optical communication and biomedical devices

www.nature.com/scientificreports OPEN High performance Raman amplifier: applications in optical communication and biomedical devices Fathy M. Mustafa 1, Ahmed F. Sayed 2, Moustafa H. Aly 3 & Tarek M. Said 4,5 High-performance Raman Amplifiers (RAs) have emerged as a powerful solution for enhancing signal strength and transmission quality in advanced optical systems. By utilizing stimulated Raman scattering in optical fibers, these amplifiers provide wide bandwidth, low noise figures, and flexible gain profiles, making them highly suitable for next-generation high-capacity communication networks. In addition to their established role in long-haul and metro optical communication links, RAs are increasingly applied in biomedical devices that rely on precise optical signal delivery. Key medical applications include Optical Coherence Tomography (OCT), laser-based imaging systems, fiber-optic endoscopy, and biomedical sensing platforms, where improved optical gain directly enhances imaging depth, resolution, and diagnostic accuracy. This work highlights the operational principles, performance advantages, and cross-domain applications of high-performance RAs, emphasizing their growing significance in both communication infrastructure and advanced medical diagnostic technologies. Three backward configurations: two, three and four cascaded Ras are investigated. Simulations are performed with pump powers of 200, 400, and 600 mW using three fiber types: single-mode fiber (SMF), TrueWave, and FreeLight, each with a 100 km amplifier length. The four-stage configuration achieves the highest performance, with 63 dB gain and 59.9 dBm output power at 600 mW using TrueWave fiber, demonstrating significant improvement in gain and output power over related work. Based on our results, RA boosts the returned OCT signal before detection, increasing SNR, enables deeper tissue imaging, and improves axial resolution and contrast, especially in low-reflectivity tissues. For MRI and CT, long-distance sensing along its gantry without electronic repeaters, Higher accuracy in detecting weak sensor signals and Support for multi-sensor networks inside the MRI machine. Keywords Raman amplifier (RA), Backward pumping, Pumping power, Amplifier gain, Optical coherence tomography (OCT) The rapid growth of global data traffic, driven by the increasing demand for high-capacity broadband and emerging applications such as cloud computing, 5G/6G networks, and quantum communication, places significant pressure on optical communication systems to deliver higher transmission reach and bandwidth1,2. Optical amplifiers are a cornerstone of these systems, enabling long-haul transmission by compensating for fiber attenuation without the need for optical-to-electrical conversion3. The ever-increasing demand for high-capacity and long-haul optical transmission systems has placed stringent requirements on optical amplifiers to deliver low-noise, broadband gain while maintaining system scalability. Raman amplification, based on the principle of stimulated Raman scattering (SRS), has emerged as a key solution due to its ability to provide distributed gain along the transmission fiber and its spectral flexibility compared to conventional Erbium-Doped Fiber Amplifiers (EDFAs)4,5. Amplifier technologies are used in biomedical engineering, with a focus on implantable and portable biomedical devices. It discusses design requirements for amplifiers used in neural recording, 1Electrical Engineering Department, Faculty of Engineering, Beni-Suef University, Beni-Suef, Egypt. 2Transmission Department, Telecom Egypt, Fayoum, Egypt. 3Electronics and Communication Engineering Department, College of Engineering and Technology, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Egypt. 4Electrical Engineering Department, College of Engineering, King Faisal University, 31982 Al-Ahsa, Saudi Arabia. 5Electrical Engineering Department, College of Engineering, Fayoum University, Fayoum 63514, Egypt. email: Scientific Reports | (2026) 16:16253 | https://doi.org/10.1038/s41598-026-37650-4 1 biomedical signal processing, and wireless medical systems. Key findings highlight the importance of achieving high gain, low noise, and biocompatibility in amplifier designs6. Unlike discrete amplifiers, Raman amplifiers allow gain tailoring by selecting appropriate pump wavelengths and power levels, thereby enhancing system reach and capacity in Dense Wavelength Division Multiplexing (DWDM) networks7. The efficiency of Raman gain strongly depends on pump configuration and pump power distribution. Typically, three pumping schemes are employed: forward pumping, backward pumping, and bidirectional pumping8. Backward pumping is widely adopted as it reduces nonlinear interactions between pump and signal, minimizes Relative Intensity Noise (RIN) transfer, and provides better noise performance9. Meanwhile, forward pumping offers simpler implementation but is more susceptible to pump–signal crosstalk. Hybrid or bidirectional pumping combines the benefits of both approaches, allowing optimized trade-offs between gain, noise, and nonlinear effects Furthermore, multiple pump sources are often employed to achieve gain flattening over wide bandwidths10,11. The Raman gain directly influences the quality of the received signal, particularly in terms of Optical Signal-to-Noise Ratio (OSNR), Bit Error Rate (BER), and overall system capacity. Higher pump power levels generally increase Raman gain, but excessive power may lead to nonlinear impairments and amplifier-induced noise12. The integration of an Optical Parametric Amplifier (OPA) with Optical Coherence Microscopy (OCM) shows significant improvements in SNR (up to 15 dB) and penetration depth when imaging in turbid biological tissues. The OPA effectively enhances imaging resolution and contrast in highly scattering environments, making it highly suitable for biomedical imaging applications13. In optical networks, RAs are used in priority-based routing and wavelength assignment with traffic grooming and in priority-based dispersion-reduced wavelength assignment14,15. Fiber type and effective areas also play critical roles in determining the achievable gain and received signal performance16. Truewave and Freelight fibers exhibit different nonlinear thresholds and dispersion properties compared to standard single-mode fiber (SMF), thereby impacting the maximum signal power and achievable system reach17. Optimizing the balance between Raman gain, pump power, and fiber characteristics is therefore essential to improving the quality of the received optical signal18. One major challenge is the requirement for high pump power to achieve significant Raman gain. Since the Raman gain coefficient is relatively small, tens to hundreds of milliwatts of pump power are typically needed, which raises concerns about nonlinear impairments and system stability19. By leveraging optical parametric am (...truncated)