arXiv subjects

Jakub Bogusławski

Publications and source records attributed to Jakub Bogusławski.

4 recordsLinked to original sources

arXiv2024

Efficient multiphoton microscopy with picosecond laser pulses

Multiphoton microscopes employ femtosecond lasers as light sources because the high peak power of the ultrashort pulse allows for multiphoton excitation of fluorescence in the examined sample. However, such short pulses are susceptible to broadening in a microscope's highly dispersive optical elements and require careful dispersion management, otherwise decreasing excitation efficiency. Here, we have developed a 10 nJ Yb:fiber picosecond laser with an integrated pulse picker unit and evaluated its performance in multiphoton microscopy. Our results show that performance comparable to femtosecond pulses can be obtained with picosecond pulses only by reducing the pulse repetition rate and that such pulses are significantly less prone to the effect of chromatic dispersion. These findings proved that the temporal compression of fiber lasers is not always efficient, and it can be omitted by using a smaller and easier-to-use all-fiber setup. \c{opyright} 2024 Optica Publishing Group. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.

physics.optics↗

arXiv2024

Intracavity filtering in SESAM mode-locked fiber lasers: soliton effects and noise performance

We characterized and analyzed the effect of intracavity spectral filtering in the Er:fiber laser mode-locked with a semiconductor saturable absorber mirror (SESAM). We studied the dispersive properties of bandpass filters and their influence on the characteristics of generated soliton pulses. Our analysis showed that various sideband structures were induced by the filter dispersion profiles and shaped through the interaction of the soliton with the dispersive wave. In addition, intracavity filtering improved the intensity and phase noise of the laser significantly, and we showed optimal filtering conditions for both types of noise. By adding a 10 nm bandpass filter to the laser resonator, the intensity and phase noise were improved 2- and 2.6 times, respectively.

physics.optics↗

arXiv2023

Increasing brightness in multiphoton microscopy with low-repetition-rate, wavelength-tunable femtosecond fiber laser

Many experiments in biological and medical sciences currently use multiphoton microscopy as a core imaging technique. To date, solid-state lasers are most commonly used as excitation beam sources. However, the most demanding applications require precisely adjusted excitation laser parameters to enhance image quality. Still, the lag in developing easy-to-use laser sources with tunable output parameters makes it challenging. Here, we show that manipulating the temporal and spectral properties of the excitation beam can significantly improve the quality of images. We have developed a wavelength-tunable femtosecond fiber laser that operates within the 760 - 800 nm spectral range and produces ultrashort pulses (below 70 fs) with a clean temporal profile and high pulse energy (1 nJ). The repetition rate could be easily adjusted using an integrated pulse picker unit within the 1 - 25 MHz range and without strongly influencing other parameters of the generated pulses. We integrated the laser with a two-photon excited fluorescence (TPEF) scanning laser microscope and investigated the effect of tunable wavelength and reducing the pulse repetition rate on the quality of obtained images. Using our laser, we substantially improved the images brightness and penetration depth of native fluorescence and stained samples compared with a standard fiber laser. Our results will contribute to developing imaging techniques using lower average laser power and broader use of tailored fiber-based sources.

physics.optics↗

arXiv2020

Frequency-doubled femtosecond Er-doped fiber laser for two-photon excited fluorescence imaging

A femtosecond frequency-doubled Erbium-doped fiber laser with adjustable pulse repetition rate is developed and applied in two-photon excited fluorescence microscopy. The all-fiber laser system provides the fundamental pulse at 1560 nm wavelength with 22 fs duration for the second harmonic generation, resulting in 1.35 nJ, 60 fs pulses at 780 nm. The repetition rate is adjusted by a pulse picker unit built-in within the amplifier chain, directly providing transform-limited pulses for any chosen repetition rate between 1 and 12 MHz. We employed the laser source to drive a scanning two-photon excited fluorescence microscope for ex vivo rat skin and other samples imaging at various pulse repetition rates. Due to compactness, ease of operation, and suitable pulse characteristics the laser source can be considered as an attractive alternative for Ti:sapphire laser in biomedical imaging.

physics.optics↗