Researchers have demonstrated a mode-locked laser based on erbium-ion-implanted silicon nitride photonic integrated circuits (PICs).
The laser operates in the Mamyshev oscillator architecture, using alternating spectral filtering and self-phase modulation to achieve mode-locking. It delivers a 176-MHz pulse train with nanojoule pulse energy, exceeding previous PIC-based sources by two orders of magnitude.
The output can be linearly compressed to 147 fs and directly drives a 1.5-octave-spanning supercontinuum in a Si3N4 waveguide without additional amplification.
A compact terahertz time-domain spectrometer driven by this source achieved a bandwidth of 5 THz and a 90-dB dynamic range, and was used for non-contact chemical analysis and inspection.