Physics phenomena of multipulse compounds have enriched the life ultrashort pulses beyond traditional pulse singlets in passively mode-locked fiber lasers. By developing a near zero-dispersion laser, we report on generation dispersion-managed soliton (DMS) molecules. During propagation laser cavity, broadband DMSs experience breathing process (i.e., periodic compression and stretch width), which facilitates various molecule evolutions from singlets. In particular, tightly bound DMS pairs,...

Band-limited angular spectrum (BLAS) methods can be used for simulating the diffractional propagation in near field, far tilted system, and nonparaxial system. However, it does not allow free sample interval on output calculation window. In this paper, an improved BLAS method is proposed. This new algorithm permits a selective scaling of observation window size number plane. The based linear convolution, which calculated by fast Fourier transform effectively.

Laser stealth dicing can realize material separation with negligible surface damage, but severe aberrations in thick materials degrade processing quality. This Letter presents a nonlinear point-to-point transformation method combined spherical aberration compensation to achieve aberration-free axial multi-focus beams. The focus peak intensity increases 7 times at depth of 0.5 mm after compensation, and reaches 44 3.5 mm. Spherical experiments showed that the width heat-affected zone remains...

We report on the generation of L-band noise-like pulses (NLPs) in a bidirectional mode-locked fiber laser. Benefiting from absence isolator and in-band absorption erbium-doped fiber, at waveband over 1600 nm are delivered this oscillator. With appropriate settings, conventional solitons can evolve into NPLs both clockwise counter directions, which validated by sideband-free spectral shape distinguishable autocorrelation trace. In addition, it is experimentally found that NLP tends toward...

Laguerre-Gaussian (LG) mode decomposition has found applications in various optics fields. However, numerical LG expansion for arbitrary field is still a problem, since the physical dimension of modes would vary with three parameters-the beam waist width w, radial index p, and azimuthal m, which make it difficult to determine optimal value w truncation order on p. Here general method an developed. It that local frequency distribution function consists two parts, quasi-periodic part chirped...

Diode pumped rare gas atoms lasers (DPRGLs) are potential candidates of the high-energy lasers, due to advantages high laser power and optical conversion efficiency. In this paper, a two-stage excitation model DPRGLs is established including discharge semiconductor pump study energy loss mechanism obtain total The results numerical simulation agree well with those Rawlins et al.'s experiment. Through parameter optimization, efficiency reach 51.5% 62.7% respectively, at intensity 50 kW/cm2...

The method, based on the rotation of angular spectrum in frequency domain, is generally used for diffraction simulation between tilted planes. Due to spectrum, interval sampling points Fourier domain not even. For conventional fast transform (FFT)-based methods, a interpolation needed get approximate value equidistant points. However, due numerical error caused by interpolation, calculation accuracy degrades very quickly as angle increases. Here, propagation planes transformed into problem...

We report an efficient method to generate arbitrary three-dimensional (3D) parallel multifoci inside a material. Taking into account the numerical aperture of objective lens and refractive index material, Ewald cap was modified with longer radius, then whole 3D intensity distribution material could be calculated using only single Fourier transform (FT). By introducing adaptive weight coefficient, uniformity improves from 81.3% 98.9%. adjusting axial resolution cap, 85.9% 99.7%. In...

Carbon fiber reinforced polymer (CFRP) has been widely used in the aerospace industry and other fields, but its processing is still subject to many restrictions. A femtosecond laser helical drilling device proposed. It can realize beam deflection translation through a scanning galvanometer pair of lenses, respectively, finally obtain effect oblique focusing. With combination spiral path focus feed, non-taper high-quality materials be realized. CFRP were processed this method, influences...

There has been recent interest in diode pumped metastable rare gas lasers (DPRGLs) and their scaling to higher powers, due the advantages of excellent beam quality high quantum efficiency. In this paper, a cw amplifier (DPRGA) with single-pass longitudinally configuration is studied theoretically based on master oscillator power (MOPA). A five-level kinetic model DPRGAs first established. Then, influences gain medium density, pump seed laser intensities length DPRGA performance are simulated...

We report an approach for continuous tuning of the central wavelengths a femtosecond nondegenerate doubly resonant optical parametric oscillator (DRO). Key in this scheme is insertion wavelength-selective element into DRO cavity-length-locking system, which allows selected narrow-band emission from to be detected and enables cavity length locked away peak its resonances. In preliminary experiment, we demonstrated with central-wavelength continuously-tunable over each resonances achieved...

A new type of toric concave mirror laser resonator with a big Fresnel number is presented. The M2 factor an output beam the 8.05 close to that plane-concave stable 2.01, volume mode about four times resonator. 3.2 kW doughnut-like 1.9 obtained experimentally by using on high-power transverse flow CO2 laser, while similar power 7.5 same number. Results show can permit operation high and quality in large gain volume.

It is of great significance to control the energy, location, topological charge, and other parameters each beam in three-dimensional space. Thus, optical array proposed widely used processing, communication, microscopy, storage, fields. However, current methods generate are only effective specific scenarios. In this work, we present an efficient general method, which separates iterative calculation parameter selection by introducing a special mapping space, allowing generation arrays with...

A positive branch unstable-waveguide hybrid resonator has been designed for a RF-excited slab CO2 laser of 100 W level. The output beam mode and the propagation characteristics in two directions unstable waveguide were investigated by numerical experimental methods. results show that was collimated direction, an approximate fundamental direction with divergence angle 12 mrad. power decreased 50% misaligned tail mirror 1.5 mrad, close to 0 more than 3

The unstable-waveguide hybrid resonator emits a rectangular, simple astigmatic beam with large number of high-spatial-frequency oscillations in the unstable direction. To equalize quality, this paper, shaping system spatial filter for was investigated by numerical simulation and experimental method. high-frequency components fundamental mode output direction are separated focus lens. eliminated following filter. A nearly Gaussian-shaped approximately equal propagation factor M² two...