The article reviews recent advances in strong light-matter coupling in van der Waals materials, particularly focusing on transition metal dichalcogenides (TMDs). TMDs, due to their exceptional electronic and optical properties, have emerged as promising materials for exploring novel polaritonic physics and devices. The review discusses various optical structures strongly coupled to TMD materials, such as Fabry-Perot cavities, photonic crystals, and plasmonic nanocavities. It highlights the intriguing properties and device applications of TMD polaritons, including valley polarization, nonlinear interactions, and electromagnetic tuning. The article also explores the potential for controlling polaritonic properties through electrical and magnetic fields, as well as ultrafast dynamics of polaritons in TMD microcavities. Finally, it reviews the applications of polaritons in optoelectronic devices, such as polariton lasers, programmable polaritons, and polariton LEDs. The review aims to inspire further investigations and developments in the field of polaritonic devices and technologies within van der Waals materials.The article reviews recent advances in strong light-matter coupling in van der Waals materials, particularly focusing on transition metal dichalcogenides (TMDs). TMDs, due to their exceptional electronic and optical properties, have emerged as promising materials for exploring novel polaritonic physics and devices. The review discusses various optical structures strongly coupled to TMD materials, such as Fabry-Perot cavities, photonic crystals, and plasmonic nanocavities. It highlights the intriguing properties and device applications of TMD polaritons, including valley polarization, nonlinear interactions, and electromagnetic tuning. The article also explores the potential for controlling polaritonic properties through electrical and magnetic fields, as well as ultrafast dynamics of polaritons in TMD microcavities. Finally, it reviews the applications of polaritons in optoelectronic devices, such as polariton lasers, programmable polaritons, and polariton LEDs. The review aims to inspire further investigations and developments in the field of polaritonic devices and technologies within van der Waals materials.