Purpose <p>This study presents a comprehensive analytical investigation of exact wave solutions within the framework of the Three-Phase-Lag Model (TPLM) of thermoelasticity, incorporating the effects of laser pulse excitation and temperature-dependent material properties. The work aims to clarify the coupled interaction between thermal and elastic fields and to examine how temperature-sensitive coefficients influence thermoelastic wave propagation under varying thermal and mechanical conditions.</p> Method <p>The governing coupled nonlinear thermoelastic equations are analyzed using the Improved Modified Extended Tanh Function (IMETF) method. This analytical approach provides a flexible framework for constructing diverse classes of exact wave solutions with adjustable free parameters. The model incorporates temperature-dependent physical coefficients together with laser pulse loading to accurately represent ultrafast thermo-mechanical processes in advanced materials.</p> Results <p>Several families of exact analytical solutions are successfully obtained, including hyperbolic, bright soliton, and exponential wave structures. The derived solutions reveal important characteristics of thermoelastic wave propagation, such as dispersion, attenuation, and nonlinear interaction mechanisms within the TPLM framework. Graphical representations of displacement, temperature distribution, and stress tensor components demonstrate the significant effects of temperature dependence and laser pulse excitation on the thermoelastic response of the medium. The results further show that the IMETF method efficiently generates physically meaningful solutions with rich dynamical behaviors. </p> Conclusions <p>The study confirms that the Three-Phase-Lag Model provides an effective and advanced framework for describing thermoelastic phenomena in temperature-dependent media subjected to ultrafast laser loading. The obtained exact solutions enrich the theoretical understanding of nonlinear thermoelastic wave dynamics and provide valuable insights into the coupled thermal and mechanical behavior of modern engineering materials. Moreover, the IMETF approach proves to be a powerful and versatile analytical tool for investigating complex thermoelastic systems. This work presents a comprehensive analytical study of exact wave solutions within the Three-Phase-Lag Model (TPLM) thermoelasticity theory, incorporating both laser pulse excitation and temperature-dependent material properties. The governing coupled equations, which clarify the interplay among thermal and elastic fields, are addressed using the Improved Modified Extended Tanh Function (IMETF) approach. A central aspect of the study is the inclusion of temperature-sensitive coefficients, which significantly affect thermoelastic behavior under varying thermal and mechanical conditions. Unlike conventional methods, the IMETF scheme offers a more versatile framework that enables the construction of a broad spectrum of analytical waveforms with tunable free parameters. The derived families of solutions—including hyperbolic, bright soliton, and exponential types—capture distinct features of wave propagation in temperature-dependent thermoelastic media. These solutions not only the enrich the theoretical understanding but also provide physical insights into dispersion, attenuation, and interaction mechanisms within the TPLM. To complement the analysis, graphical illustrations of displacement, temperature, and stress tensor responses are provided, clearly demonstrating the effects of temperature dependence and laser pulse input. The results emphasize the importance of advanced frameworks such as TPLM in accurately representing the dynamic behavior of modern materials under ultrafast thermo-mechanical loading.</p>