Accession Number:

AD1099916

Title:

Nanosecond Mid-Infrared Pulse Generation Via Modulated Thermal Emissivity

Descriptive Note:

Journal Article - Open Access

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC WASHINGTON United States

Report Date:

2019-06-05

Pagination or Media Count:

8.0

Abstract:

We demonstrate the generation of nanosecond mid-infrared pulses via fast modulation of thermal emissivity enabled by the absorption of visible pump pulses in unpatterned silicon and gallium arsenide. The free-carrier dynamics in these materials result in nanosecond-scale modulation of thermal emissivity, which leads to nanosecond pulsed thermal emission. To our knowledge, the nanosecond thermal-emissivity modulation in this work is three orders of magnitude faster than what has been previously demonstrated. We also indirectly observed subnanosecond thermal pulses from hot carriers in semiconductors. The experiments are well described by our multiphysics model. Our method of converting visible pulses into the mid infrared using modulated emissivity obeys different scaling laws and can have significant wavelength tunability compared to approaches based on conventional nonlinearities.

Subject Categories:

  • Electrooptical and Optoelectronic Devices
  • Radio Communications
  • Optics
  • Computer Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE