pulsedlaser

A pulsed laser is a laser that emits light in brief bursts rather than a continuous beam. Each pulse contains a large amount of energy, resulting in high peak power while keeping average power manageable. Pulse durations range from femtoseconds to microseconds.

Pulsed operation is achieved through methods such as Q-switching (active or passive) which stores energy in the gain medium and releases it rapidly, mode locking which phase synchronizes cavity modes to produce a train of ultrashort pulses, and gain switching which modulates the pump input to generate pulses. External modulators and pulse shapers can tailor pulse envelopes.

Key parameters include pulse duration, repetition rate, energy per pulse, peak power, and average power. The average power equals pulse energy times repetition rate. Ultrashort pulses (femtoseconds to picoseconds) enable nonlinear optical effects and high-precision micromachining; longer pulses (nanoseconds to microseconds) can be more efficient for some materials processing.

Common platforms include solid-state lasers such as Nd:YAG, Nd:YVO4, and Ti:sapphire; fiber lasers; diode-pumped devices; dye and CO2 lasers. Ultrashort-pulse systems typically use mode-locked Ti:sapphire or fiber lasers with dispersion management.

Applications span material processing (drilling, micromachining, surface structuring), biomedical procedures (precise surgery and ophthalmology), spectroscopy and nonlinear optics, micromachining, LIDAR, and optical communication research.

Advantages include high peak power with reduced average heating, precision, and the ability to control pulse timing and duration. Limitations involve system complexity, cost, and challenges such as dispersion management and thermal effects. Safety concerns focus on eye and skin hazards from high-peak-power pulses.