The nonlinear optical transition bleaching in tellurene

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanophotonics

Background:

• Tellurene exhibits remarkable linear and nonlinear optical properties due to its 2D phases and optical anisotropy.
• These properties make tellurene a promising material for nanophotonics applications.

Purpose of the Study:

• To investigate the ultrafast nonlinear optical (NLO) properties of alpha-tellurene (α-tellurene).
• To explore the influence of probe pulse photon energy on NLO response.
• To elucidate the underlying photophysical mechanisms contributing to NLO enhancement.

Main Methods:

• Ultrafast nonlinear optical (NLO) characterization using Z-scan and pump-probe techniques.
• Broadband spectral region analysis.
• Density Functional Theory (DFT) computations.

Main Results:

• Observed saturable absorption and band filling effects in α-tellurene, consistent with the Pauli exclusion principle.
• DFT analysis indicated enhanced NLO response in the ultraviolet-visible spectrum due to increased intraband transitions.
• A negative correlation was found between probe pulse photon energy, differential transmission signal, and calculated joint density of states (JDOS).

Conclusions:

• The study provides insights into the intrinsic photophysics of 2D tellurene.
• The findings highlight the potential of tellurene for advanced photonic and optoelectronic devices.
• Understanding these NLO properties is key to optimizing tellurene-based nanophotonics.