A heavily doped germanium pyramid array for tunable optical antireflection in the broadband mid-infrared range

Tunability of the Dielectric Function of Heavily Doped Germanium Thin Films for Mid-infrared Plasmonics

Tunability and Losses of Mid-infrared Plasmonics in Heavily Doped Germanium Thin Films

Heavily-doped semiconductor films are very promising for application in mid-infrared plasmonic devices because the real part of their dielectric function is negative and broadly tunable in this wavelength range. In this work we investigate heavily n-type doped germanium epilayers grown on different substrates, in-situ doped in the 10 to 10 cm range, by infrared spectroscopy, first principle cal...

Fabrication of mid-infrared plasmonic antennas based on heavily doped germanium thin films

In this work, the growth and the fabrication of heavily doped germanium plasmonic antennas for mid-infrared applications is reported. By tuning the phosphorus doping concentration and the antenna geometrical parameters, plasma frequencies for targeting the 8-15 μm spectral region are achieved. 1 μm thick, heavily doped (2.3 × 10 cm ) germanium was used to fabricate dipole antennas of 800 nm wid...

Mid-Infrared Sensing Using Heavily Doped Germanium Plasmonics on Silicon Substrates

Optical Activation of Germanium Plasmonic Antennas in the Mid-Infrared.

Impulsive interband excitation with femtosecond near-infrared pulses establishes a plasma response in intrinsic germanium structures fabricated on a silicon substrate. This direct approach activates the plasmonic resonance of the Ge structures and enables their use as optical antennas up to the mid-infrared spectral range. The optical switching lasts for hundreds of picoseconds until charge rec...