An efficient silicon-based light source presents an unreached goal in the field of photonics, due to Silicon’s indirect electronic band structure preventing direct carrier recombination and subsequent photon emission. Here we utilize inelastically tunneling electrons to demonstrate an electrically-driven light emitting silicon-based tunnel junction operating at room temperature. We show that such a junction is a source for plasmons driven by the electrical tunnel current. We find that the emission spectrum is not given by the quantum condition where the emission frequency would be proportional to the applied voltage, but the spectrum is determined by the spectral overlap between the energy-dependent tunnel current and the modal dispersion of the plasmon. Experimentally we find the highest light outcoupling efficiency corresponding to the skin-depth of the metallic contact of this metal-insulator-semiconductor junction. Distinct from LEDs, the temporal response of this tunnel source is not governed by nanosecond carrier lifetimes known to semiconductors, but rather by the tunnel event itself and Heisenberg’s uncertainty principle. Finally We discuss a path for single photon emission via the Coulomb blockade effect leading to single electron tunneling.
We show that inelastically-scattering tunnel electrons are a source for electric plasmon generation. We experimentally demonstrate such electrically-driven light-emitting tunnel junction by forward biasing a Fermi sea against a doped semiconductor across a nanometer-thin tunnel gap. Light emission at room temperature is found in the visible frequency range corresponding to a spectral power dependency of the tunnel current and the plasmonic mode. The response time (speed) of such a tunnel junction scales inverse exponentially with the tunnel gap thickness approaching Tpbs for <0.5nm thin gaps. Lastly, since tunneling allows for single-charge events, the possibility for single-photon generation is expected.
We present a comprehensive experimental study of the technique of Longitudinal Mode Filling (LMF) applied to the
reduction of Stimulated Brillouin Scattering (SBS), in Ytterbium Doped Fibre Amplifiers (YDFA) at the wavelength of
1064 nm. Pulse durations and Mode Field Diameters (MFD) lie in the ranges of 10 - 100 ns and 10 - 35 μm,
respectively. Input pulse-shaping is implemented by means of direct current modulation in multimode Laser-Diode
seeds. This evidences a number of interests in the development of robust and low cost Master Oscillator Power
Amplifiers (MOPA). Highly energetic, but properly shaped, nanosecond pulses may be produced this way without any
need of additional electro-optical means for in-line phase and amplitude modulation. Seeds consist of Distributed Feed-
Back (DFB) and Fibre Bragg Gratings (FBG) with different fibre lengths. We demonstrate the benefit of LMF with
properly controlled mode spacing, in combination with chirp effects due to fast current transients in the semiconductors,
in order to deal with SBS thresholds in the range of a few to some hundred μJ. The variations of the SBS threshold are
discussed versus the number of longitudinal modes, the operating conditions of the selected seed and pulse-shaping