A research team led by Qiu et al. has developed a groundbreaking integrated mode-locked laser using a Mamyshev oscillator architecture and erbium-ion-implanted silicon nitride waveguides. Published in Nature, the laser achieves nanojoule-level pulse energies on a photonic chip—two orders of magnitude higher than previous integrated systems—while operating at a 176 MHz repetition rate. This bridges the performance gap between conventional fiber lasers and compact photonic integrated circuits, overcoming a long-standing limitation in ultrafast photonics.

The innovation leverages erbium’s gain properties within silicon nitride, a material compatible with CMOS fabrication, enabling scalable, wafer-level production. The Mamyshev oscillator design uses alternating spectral filtering and nonlinear self-phase modulation to achieve stable, self-regulating mode-locking without external stabilization. The pulses can be compressed to 147 femtoseconds, making them ideal for precision applications like terahertz spectroscopy and nonlinear optical processes.

The team demonstrated a miniaturized terahertz time-domain spectrometer powered by the laser, achieving a 5 THz bandwidth with 90 dB dynamic range—performance suitable for portable chemical sensing. This proves the laser’s viability beyond the lab, with potential applications in environmental monitoring, security screening, and medical diagnostics. The integration of all components on a single chip marks a significant step toward fully integrated photonic systems.