<p>The increasing demand for high-speed and energy-efficient optical access networks requires adaptive solutions for varying traffic conditions. Conventional passive optical networks (PONs) employ a fixed power transmitter at the optical network unit (ONU), resulting in inefficient power utilization under varying load conditions. This paper proposes an energy-efficient scheme based on Access load difference between ONUs with Dynamic Wavelength Switching (ALD-DWS). In this scheme, a multi-level transmitter architecture is proposed that dynamically activates sub-transmitters based on real-time traffic demand. The proposed approach reduces energy consumption while maintaining acceptable system performance. The system is modeled and evaluated using OptiSystem simulations under different traffic loads. Performance of the system is analyzed in terms of bit error rate (BER), Q-factor, and received optical power. The results demonstrate that the proposed scheme achieves improved energy efficiency with negligible effect on signal quality as compared to fixed power conventional systems. The adaptive mechanism ensures scalable and reliable performance, making it suitable for next-generation optical access networks. The proposed technique, i.e., ALD-DWS, is based on a multi-level design for the transmitter at each ONU, where the sub-transmitters are enabled as per the load offered. Load difference at ONU is checked, and according to that, DWS will switch “ON” the required module such that if the data rate is less than 5 Gbps, then only the sub-transmitter, such as 2 Gbps×2, is switched “ON”. So, the results proposed shows 69% energy savings when the load is less than 5Gbps, 41% for 10–15 Gbps, and around 21% for 15-20Gbps. The proposed ALD-DWS technique proves to be cost-effective and can be considered for better scalability and reliability.</p>