Ultrafast Time-Solved Infrared Spectroscopic Investigation of Phase-Change Materials for Optoelectronics
Abstract
Phase-change materials afford a drastic change in their optoelectronic properties that is far beyond what is possible in conventional optoelectronic materials. Their implementation in integrated optoelectronics promise to reduce device footprint, speed, and energy cost. Also, they bring brandnewfunctionalities in that the phase transition process is non-volatile and nonlinear so that photonic neuromorphic computing has be envisioned. However, the key to the success of phasechange photonics is to reduce the energy consumption needed for phase-transition, which currently solely relies on thermal processes by heating the materials, and to search for new materials whose phase-transition is non-thermal. To investigate the intrinsic phase transition dynamics and discover non-thermal transition pathways in new phase-change materials, we propose to acquire and construct a unique ultrafast, time-resolved optical spectroscopic measurement system. The systemuniquely provides ultrashort laser pulses in a widely tunable spectral range from near-infrared (1m in wavelength) to mid-infrared (>5 m in wavelength) to provide both stimulation and probing of the phase transition in a variety of materials. The pulse width will be less than 100 femtoseconds and the pulse energy higher than one J across the whole spectral range. The broadband capabilityis critical to explore non-thermal phase-transition in materials from semi-metal to semiconductors, which involve many kinds of possible resonant excitation pathways such as excited-state dynamics, defect-state charge, and polymorphic phase-transition. The wide infrared band of the systems output will also allow investigating the intriguing phase-transition in emerging 2D quantum materials, many of which have a narrow bandgap in the mid-infrared region. The high pulse energy will allow splitting into multiple pulses to enable pump-probe measurement, as well as probing nonlinear light-matter interactions. Acquisition of this system will significantly enhance the research capability of the PIs group for an ongoing MURI project that aims to discover new phase change materials and explore their application in integrated photonics for optical communication and photonic neuromorphic computing. The tool will also be accessible to many other research groups at the University of Washington, to benefit their DoD-funded research projects in 2D material optoelectronics, quantum materials and metamaterials.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 20, 2020
- Source ID
- N000142012645
Entities
People
- Mo Li
Organizations
- Office of Naval Research
- United States Navy
- University of Washington