In recent years, chalcogenide-based phase change materials have been explored for optoelectronic and photonic applications including free-space optical modulators primarily owing to their promising features, such as pronounced contrast in refractive indices, absorption coefficients, and reflectivity during reversible phase transition between amorphous and crystalline states upon electrical or electrical stimulus. Also, these materials show potential for free space reflective optical modulators at the 1550 nm wavelength, which aligns with the low-loss transmission window of optical fibers. Their broad spectral tunability and fast response times, as fast as 700 picoseconds, make them well-suited for applications that require rapid modulation and precise control of reflected light.

Furthermore, ongoing research efforts are focused on optimizing the performance of chalcogenide-based modulators, including enhancing modulation speeds, reducing power consumption, and improving overall efficiency. As these materials advance, they contribute significantly to the evolution of 1550 nm wavelength-free space-reflective optical modulators, enabling possible innovative solutions in telecommunications, sensing, and quantum communication. In this seminar, the importance of Laser communication compared to RF communication will be discussed. Also, the design of novel phase change materials capable of modulation efficiency above 80% will be discussed in comparison with the existing reflective optical modulators.