All-multimode fiber spatiotemporal mode-locked figure-eight laser based on multimode gain fiber.

In this paper, we report for the first time on an all-multimode fiber spatiotemporal mode-locked figure-eight laser operating at 1.0 µm. This laser utilizes a multimode gain fiber and a nonlinear amplifying loop mirror mechanism. It can generate mode-locked noise-like pulses at different central wavelengths. Additionally, we observed the presence of a multi-soliton state within the cavity by reducing intracavity gain. This study contributes to a broader investigation of various pulse phenomena in spatiotemporal mode-locked lasers and provides valuable insights into further exploring the evolution of spatiotemporal dynamics in such systems.

Passively Q-switched Nd:YVO4 laser operating at 1.3 µm with a graphene oxide and ferroferric-oxide nanoparticle hybrid as a saturable absorber.

A self-made saturable absorber (SA) based on hybridized graphene oxide (GO) and ${{\rm Fe}_{3}}{{\rm O}_{4}}$Fe3O4 nanoparticles (FONP) was inserted into a linear cavity to generate a passively $ Q $Q-switched solid-state ${\rm Nd}\text:{{\rm YVO}_4}$Nd:YVO4 laser operating at the 1.3 µm waveband. The laser had a minimum pulse width of 163 ns and a maximum repetition rate of 314 kHz. This experiment, to the best of our knowledge, is the first to demonstrate that hybridized GO and FONP (GO-FONP) can be used as an SA in passively $ Q $Q-switched pulse lasers. Results show that GO-FONP has the potential to be used for passively $ Q $Q-switched laser generation.

Efficient self-stimulated Raman scattering with simultaneously self-mode-locking in a diode-pumped Nd:GdVO4 laser.

We demonstrated an efficient diode-pumped picosecond self-Raman Nd:GdVO4 laser with the simultaneous processes of stimulated Raman scattering and self-mode-locking in the same crystal. The design of self-mode-locked was theoretically analyzed, and a compact and feasible dual-concave cavity was adopted. The maximum output power of the first-Stokes Raman laser was 736 mW with the repetition rate of 1.51 GHz. In addition, the second-harmonic generation of a yellow laser at 586.5 nm is accomplished with an external LiB3O5 crystal.

Compact Q-switched and mode-locked Nd3+:YVO4/Cr4+:YAG self-Raman laser.

Compact passively Q-switched and mode-locked Nd(3+):YVO(4)/Cr(4+):YAG self-Raman laser with high mode-locked repetition rate was demonstrated. The picosecond first Stokes at 1176 nm was successfully obtained. At the maximum incident pump power, the average output power was 95 mW with the mode-locked pulse repetition rate of 940 MHz. Yellow laser output of 588.2 nm was also realized by the use of LiB(3)O(5) frequency doubling crystal.

Compact KTA-based intracavity optical parametric oscillator driven by a passively Q-switched Nd:GdVO4 laser.

We present a compact and efficient KTA-based intracavity optical parametric oscillator (IOPO) driven by a diode-end-pumped Nd:GdVO(4)/Cr:YAG passively Q-switched laser. At the incident diode pump power of 9.2 W, signal (1.53 microm) and idler (3.47 microm) average output powers of up to 744 and 356 mW, respectively, have been obtained. The total (signal+idler) optical-to-optical conversion efficiency is as high as 12%. By using the knife-edge method, near-diffraction-limited signal and idler beams have been detected, and the M(2) factors are well within 1.2. In addition, based on the ABCD matrix theory, the impact of mode matching and the thermal lens effect on the OPO output have been analyzed.

TSA increases C/EBP­α expression by increasing its lysine acetylation in hepatic stellate cells.

CCAAT enhancer binding protein­α (C/EBP­α) is a transcription factor expressed only in certain tissues, including the liver. It has been previously demonstrated that C/EBP­α may induce apoptosis in hepatic stellate cells (HSCs), raising the question of whether acetylation of C/EBP­α is associated with HSCs, and the potential associated mechanism. A total of three histone deacetylase inhibitors (HDACIs), including trichostatin A (TSA), suberoylanilide hydroxamic acid and nicotinamide, were selected to determine whether acetylation affects C/EBP­α expression. A Cell Counting Kit­8 assay was used to determine the rate of proliferation inhibition following treatment with varying doses of the three HDACIs in HSC­T6 and BRL­3A cells. Western blot analysis was used to examine Caspase­3, ­8, ­9, and ­12 levels in HSC­T6 cells treated with adenoviral­C/EBP­α and/or TSA. Following treatment with TSA, a combination of reverse transcription­quantitative polymerase chain reaction and western blot analyses was used to determine the inherent C/EBP­α mRNA and protein levels in HSC­T6 cells at 0, 1, 2, 4, 8, 12, 24, 36 and 48 h. Nuclear and cytoplasmic proteins were extracted to examine C/EBP­α distribution. Co­immunoprecipitation analysis was used to examine the lysine acetylation of C/EBP­α. It was observed that TSA inhibited the proliferation of HSC­T6 cells to a greater extent compared with BRL­3A cells, following treatment with the three HDACIs. TSA induced apoptosis in HSC­T6 cells and enhanced the expression of C/EBP­α. Following treatment of HSC­T6 cells with TSA, inherent C/EBP­α expression increased in a time­dependent manner, and its lysine acetylation simultaneously increased. Therefore, the results of the present study suggested that TSA may increase C/EBP­α expression by increasing its lysine acetylation in HSCs.

High-repetition rate Q-switched Nd:YVO4 laser with a composite semiconductor absorber.

A diode-pumped Nd:YVO4 laser passively Q switched by a semiconductor absorber is demonstrated. The Q-switched operation of the laser has an average output power of 135 mW with a 1.6 W incident pump power. The minimum pulse width is measured to be about 8.3 ns with a repetition rate of 2 MHz. To our knowledge, this is the first demonstration of a solid-state laser passively Q-switched by such a composite semiconductor absorber.