Researchers at EPFL have created the first chip-scale ultrafast laser that matches the performance of traditional tabletop femtosecond lasers. The device delivers pulses as short as 147 femtoseconds with energies of 1.05 nanojoules.
The breakthrough, reported in Nature, was led by Professor Tobias J. Kippenberg. It uses a Mamyshev oscillator architecture on an erbium-doped silicon nitride chip. The laser cavity measures 42 centimeters but folds onto a chip the size of a match head. This design avoids components difficult to fabricate on photonic chips and resists destabilizing nonlinear effects. Co-author Zheru Qiu noted that the approach enables wafer-scale manufacturing of more than 1,000 devices at once. The work also involved researchers from Helmholtz-Zentrum Dresden-Rossendorf. Potential applications include medical diagnostics, environmental sensing, spectroscopy, and compact optical atomic clocks.