12 results about "Self-phase modulation" patented technology

The invention relates to the technical field of ultrafast laser, and discloses a negative chirp management method and device of a laser and a medium. The method comprises the following steps: pre-processing a seed pulse, outputting the seed pulse through a mode-locked optical fiber oscillator, and primarily amplifying the seed pulse through a single-mode gain optical fiber; temperature tuning negative chirp introduction is carried out, a chirp fiber grating is packaged in a temperature tuning device, and the temperature of a semiconductor chilling plate is linearly increased within a preset range, so that the second-order dispersion amount of the chirp fiber grating is changed, and controllable negative chirp is introduced into a pulse; carrying out nonlinear amplification and spectrum broadening, inputting the pulse introduced with the negative chirp into a multimode gain fiber, injecting pumping energy into the multimode gain fiber, and broadening the pulse spectrum width to be greater than a preset width by utilizing the synergistic effect of self-phase modulation, dispersion and gain; pulse width compression is carried out, and the pulse after spectrum broadening is adjusted through a transmission-type grating pair compressor, so that the ultra-narrow pulse width is obtained.

This invention provides a semiconductor mode-locked laser and its fabrication method, relating to the field of optoelectronics. It addresses the problem in existing technologies where femtosecond pulses are difficult to output due to self-phase modulation and dispersion effects, thereby avoiding the use of external pulse compression technology and reducing production costs. The semiconductor mode-locked laser includes a mirror region, a gain region, and a saturable absorption region. The gain region is located between the mirror region and the saturable absorption region and is connected to both regions. The semiconductor mode-locked laser also includes a substrate, and a chirped grating layer and an active layer disposed on the same side of the substrate. The chirped grating layer is located in the mirror region and includes multiple gratings with a grating period linearly decreasing along the emission direction of the semiconductor mode-locked laser. The active layer is located in the gain region and the saturable absorption region, and the distance between the chirped grating layer and the substrate is greater than the distance between the active layer and the substrate.

The purpose of the present invention is to provide a reflective mask blank having an absorber film that has a low refractive index n for EUV light, a high extinction coefficient k for EUV light, and excellent SPM resistance. An absorber film (18) of a reflective mask blank (10) contains palladium and at least one element X selected from the group consisting of ruthenium, iridium, and platinum. The total content of palladium and the element X in the absorber film (18) is 80 at% or more with respect to the total metal atoms contained in the absorber film (18). When the element X is only ruthenium, the content of the element X in the absorber film (18) is 20-75 at% with respect to the total atoms in the absorber film (18). When the element X contains at least one of iridium or platinum, the content of the element X in the absorber film (18) is 30 at% or more with respect to the total atoms in the absorber film (18).

The invention provides a twin beam generation method based on self-phase modulation and an application method thereof. The twin beam generation method comprises the following steps: acquiring an ultrafast laser pulse; the ultrafast laser pulse is controlled to be propagated in the optical Kerr medium, the ultrafast laser pulse interacts with the optical Kerr medium during propagation to generate self-phase modulation, two symmetric sidebands are generated, and the symmetric center of the two sidebands is a center frequency region of the ultrafast laser pulse; the two sidebands are taken out from the ultrafast laser pulse at the same time, and two twin beams with ideal quantum correlation characteristics are obtained. The ultrafast laser pulse generates self-phase modulation in the optical fiber or interacts with the optical Kerr material in a free space to generate self-phase modulation, and the method for taking out the twin beams with the quantum correlation characteristic also belongs to the category of the invention. The method can generate high-power and high-repetition-frequency ultrafast twin beams, simplifies the generation process of the twin beams, and is high in robustness, low in cost and easy to implement.

This invention discloses a tunable saddle-shaped spectrum generation device and method, belonging to the field of precision machining. It includes: a pump source, a resonant cavity with overall positive dispersion, a mode-locking device, a dispersion management device, and a spectral adjustment component. The pump source excites a gain fiber to generate laser light. The mode-locking device outputs a mode-locked pulse, and the dispersion management device provides positive dispersion. Working in conjunction with the nonlinear effect of self-phase modulation within the cavity, the mode-locked pulse spectrum is directly shaped into a saddle-shaped spectrum with a central depression. The spectral adjustment component achieves flexible tuning of the center wavelength and bandwidth of the output spectrum by adjusting the relative positions of the diffraction grating and the fiber collimator. This invention actively generates a tunable saddle-shaped spectrum from the source, eliminating the need for complex modulation elements in the amplification link. It allows for precise pre-compensation of the gain characteristics of subsequent amplifiers, effectively suppressing gain narrowing effects. It has the advantages of compact structure, low cost, high stability, and high energy utilization.

The application provides a high-power narrow-pulse-width laser and a regulation method thereof, the laser comprising a seed source, a first pulse-width regulation grating, a gain fiber, a spectrum shaping system and an amplifier; the first pulse-width regulation grating is arranged behind the seed source and is used for introducing dispersion in initial signal light; the gain fiber is used for amplifying the optical signal to realize spectrum broadening by using the self-phase modulation effect of the optical signal; the spectrum shaping system is arranged behind the gain fiber and is used for performing amplitude modulation and phase modulation on the broadened optical signal; and the amplifier is arranged behind the spectrum shaping system and is used for performing energy amplification on the shaped optical signal to obtain high-power narrow-pulse-width laser. By introducing dispersion in the initial signal light, the self-phase modulation effect of the gain fiber is used to realize spectrum broadening, and the amplitude and phase modulation of the spectrum shaping system on the broadened optical signal effectively compensates the gain narrowing and nonlinear phase accumulation in the amplification process.

The invention relates to the technical field of ultrafast laser, and discloses a pumping intensity optimization method of a laser, equipment and a medium. The method comprises the following steps: carrying out graded pumping design, and pre-amplifying signal light output by a mode-locked fiber oscillator by adopting a single-mode laser diode; the method comprises the following steps: establishing a mathematical model of pumping power and gain fiber length, and when the pumping power is increased from low power to preset power, adjusting the chirp amount of a chirp fiber grating through a temperature tuning device, and performing pre-chirp management on signal light input into a multimode gain fiber; under high pumping intensity, the initial chirp amount of signal light is optimized, so that the signal light entering the multimode gain optical fiber is in a negative chirped pulse state, the self-phase modulation and dispersion effect of the signal light when the signal light is amplified in the multimode gain optical fiber is balanced, and the stimulated Raman scattering and self-focusing phenomena are avoided; and the compressed pulse width is used as a feedback signal to realize the optimal matching of the signal light energy and the pulse width.

The invention relates to a device (10) for spectral broadening of a pulsed laser beam (12) by means of self-phase modulation with features of claim 1 and a laser arrangement (32) for spectral broadening of a pulsed laser beam (12) by means of self-phase modulation with features of the dependent claim.

The invention relates to a device (10) for spectral broadening of a pulsed laser beam (12) by means of self-phase modulation, having the features of claim 1, and to a laser arrangement (32) for spectral broadening of a pulsed laser beam (12) by means of self-phase modulation, having the features of the additional independent claim.

The application provides a multi-pass cell structure light pulse spectrum shape consistency regulation compression method and system. The method makes the structure light pulse multiple round trip propagation in the multi-pass cell and realizes the spectrum broadening dominated by self-phase modulation through the nonlinear medium, carries out spatial-spectrum interference measurement on the measured light after the spectrum broadening of the multi-pass cell and the dispersion compensation, restores the wavelength resolution spatial complex light field data, and establishes the evaluation index for representing the spectrum shape spatial consistency with the spectrum overlap index V. According to the evaluation index, the input structure light parameters, the multi-pass cell propagation parameters and the dispersion compensation parameters are feedback adjusted, so that the quantitative evaluation and optimization control of the structure light pulse spectrum broadening process and the compression output quality are realized, and the output pulse with the target spectrum width, the higher spectrum shape spatial consistency, the good compressibility and the higher peak power is obtained.

The application provides a kind of femtosecond pulse width precision adjustment compensation device and method, it is related to laser processing technical field, device includes: mode-locked seed source, stretcher, amplifier, first compressor and second compressor;Second compressor includes movable mirror, climbing mirror, grating and grating base material;Movable mirror is configured to adjust the diffraction number of femtosecond laser on the grating by changing the distance between it and grating base material;Grating base material is made of nonlinear material, for generating self-phase modulation effect under the action of femtosecond laser, realizing spectrum widening and pulse compression;By adjusting the diffraction number, the precise adjustment compensation of femtosecond pulse width is realized.The application provides a kind of technical scheme that can withstand high power, high energy laser, and realize the on-line precision adjustment compensation of pulse width.

The application provides an octave light frequency comb generation system, which can be applied to the fields of light frequency precision measurement and optical clock, etc. The octave light frequency comb generation system comprises a double-pumped Brillouin loop subsystem and a nonlinear optical fiber spectrum expansion subsystem. The application utilizes dispersion compensation and pulse narrowing technology to expand the light frequency comb generated by the double-pumped Brillouin loop subsystem to an octave light frequency comb. Fiber gratings are used to suppress two pump lights in the Brillouin light frequency comb, which is simpler and more practical than space light modulator filtering. Dispersion compensation optical fiber is used for pulse shaping, and fiber amplifier is used to improve the pulse peak power entering the second high nonlinear optical fiber, and the second high nonlinear optical fiber utilizes self-phase modulation and four-wave mixing effect for spectrum expansion. Thus, the embodiment of the application solves the problem of low pulse energy of the double-pumped Brillouin light frequency comb, and realizes high-repetition-rate octave light frequency comb.