The proposed work addresses the investigation of a group of photonic devices exhibiting nonreciprocal light-propagating properties based on atomically thin two-dimensional materials under electric bias. The realization of electrically driven nonreciprocal light propagation in a broad wavelength range will be transformative for many photonic technological areas such as optical imaging, sensing and communications. Scientifically, this program will allow optics community to deepen the fundamental understanding of electro-optical properties and light-matter interaction in two dimensional and layered materials under strong external stimuli. The proposed research may also lead to possible commercialization of inventions through the collaboration with industry partners. Moreover, the proposed program represents a cohesive effort which integrates advanced research and educational and broadening participation activities. The team members are actively involved in teaching of both undergraduate and graduate students and they will incorporate the latest research findings into their educational activities, thus providing advanced training opportunities for future workforce in photonics and semiconductor industries. Furthermore, they will leverage the research opportunities provided by this program to enhance the participation of high school students especially for those from underrepresented groups. The team will disseminate the results of this proposed research in a timely manner to a broader society through journal publications, conference presentations, or news release through the university and general media to promote the public awareness of the importance of scientific research.
Nonreciprocal photonic devices that break the time-reversal symmetry can be used for critical applications such as optical isolation and circulation for modern photonic systems. Thus, non-reciprocity devices have the potential to transform a wide range of fields in photonics, such as on-chip optical information processing, communication, and imaging. The conventional approach to achieve nonreciprocity mainly relies on bulky structures to realize substantial magneto-optic Faraday rotation, and the devices usually occupy a large footprint, posing significant challenges in integrated photonic systems. In this NewLAW project, the team proposes to develop electrically driven nonreciprocal photonic devices operating in a broad wavelength range from visible to mid-infrared by exploiting the widely tunable light-matter interaction using electric bias in atomically thin two-dimensional materials. The team consists of five principal investigators with a diverse range of background including fundamental optical physics, photonic device design, two-dimensional materials synthesis, and device realization and characterizations. To realize nonreciprocity in such compact photonic devices, the team will leverage the giant tunability of refractive index in two-dimensional transitional metal dichalcogenides materials by electrical gating and the plasmon Doppler Effect in high mobility graphene in the presence of in-plane electrical current, guided by theoretical investigations and device performance predictions. The non-reciprocal photonic devices proposed in this program are fully compatible with the popular complementary metal-oxide-semiconductor (CMOS) circuits, making them highly attractive in integrated systems. The proposed research will not only significantly advance the fundamental understanding of the light-matter interaction of two-dimensional materials with the presence of external stimuli, but also address one of the most challenging issues in modern photonic science: electrically driven optical non-reciprocity at chip-scale.
