that can generate femtosecond pulses in the visible range of the electromagnetic spectrum, a laser that produces ultrashort, bright visible-wavelength pulses for a wide range of biomedical and materials processing applications.

While the usual equipment for generating visible femtosecond pulses is complex and inefficient, fiber lasers offer a very promising alternative with the advantages of stability, reliability, small footprint, high efficiency, low cost, and high brightness. But so far, such lasers have not been able to directly generate visible light pulses with durations in the femtosecond (10-15 seconds) range.

that can operate in the visible range. The laser, based on a lanthanide-doped fluoride fiber that emits red light at 635 nanometers, achieves compressed pulses with a duration of 168 femtoseconds, a peak power of 0.73 kilowatts, and a repetition frequency of 137 megahertz. Moreover, they used a commercial blue laser diode as the energy source in the device, making the overall design more robust, compact, and cost-effective.

The team notes that if higher energy and power are available in the near future, it could be widely used in many applications. Potential applications include high-precision, high-quality biological tissue ablation, and two-photon excitation microscopy. In addition, femtosecond laser pulses could also be used to cold-ablate materials during processing, which is cleaner than using longer pulses when making cuts, given that there is no thermal effect from this process.