Available Technologies

Technology

Recent advances in photonic materials have triggered rapid growth in the development of ultra-fast optoelectronic devices. This sparks an urgent demand for techniques capable of characterizing ultrafast carrier dynamics (e.g., carrier relaxation and transportation) in these devices. A comprehensive study of these processes requires broadband spectroscopic characterization with temporal resolution down to the femtosecond (fs). Currently, pump-probe reflectometer (PPR) systems can perform either time-domain or spectral-domain measurements, but both require impractical methods for overcoming their respective shortcomings.

Researchers at UAH have developed a compact, low-cost PPR system that can simultaneously take time-domain and spectral-domain measurements. Its unique capability of achieving high temporal resolution over a broad wavelength range allows the system to map carrier dynamics onto a 2-dimentional time-wavelength space, offering new physical insights unattainable with conventional methods. Ultimately, the integration of these two types of measurements reduces the cost and complexity of a purely spectral-domain PPR system and widens the narrow wavelength range that would be the characteristic of a purely time-domain system.

This technology is able to record a material’s transient carrier behaviors with a 10-fs resolution across a 300-nm spectral range. This has profound implications for research and development in material science and laser spectroscopy. For example, this technology has already been used to measure the transient dispersion of gallium arsenide (GaAs) — a common semiconductor material which has been researched for decades. The result of this demonstration was the first-ever reported direct observation of the behaviors of transient dispersion near the GaAs band gap.