Ultrafast lasers represent one of the most significant technological advancements in modern photonics, enabling extremely precise and controlled interactions with materials and light. These lasers generate pulses with incredibly short durations, typically in the femtosecond (10⁻¹⁵ seconds) or picosecond (10⁻¹² seconds) range. Because the energy is delivered in such a brief period, ultrafast lasers can interact with materials before heat has time to spread to surrounding areas.
The fundamental principle behind ultrafast lasers lies in the generation of extremely short pulses through techniques such as mode locking. In a mode-locked laser, multiple longitudinal modes of the laser cavity are synchronized so that they interfere constructively at regular intervals, producing a train of very short and intense pulses.