32 results about "Rayleigh length" patented technology

A distributed resonator laser system using retro-reflecting elements, in which spatially separated retroreflecting elements define respectively a power transmitting and a power receiving unit. The retroreflectors have no point of inversion, so that an incident beam is reflected back along a path essentially coincident with that of the incident beam. This enables the distributed laser to operate with the beams in a co-linear mode, instead of the ring mode described in the prior art. This feature allows the simple inclusion of elements having optical power within the distributed cavity, enabling such functions as focusing / defocusing, increasing the field of view of the system, and changing the Rayleigh length of the beam. The optical system can advantageously be constructed as a pupil imaging system, with the advantage that optical components, such as the gain medium or a photo-voltaic converter, can be positioned at such a pupil without physical limitations.

An ignition facilitated electrodeless sealed high intensity illumination device is configured to receive a laser beam from a continuous wave (CW) laser light source. A sealed chamber is configured to contain an ionizable medium. The chamber has an ingress window disposed within a wall of a chamber interior surface configured to admit the laser beam into the chamber, a plasma sustaining region, and a high intensity light egress window configured to emit high intensity light from the chamber. The CW laser beam is producible by a CW laser below 250 Watts configured to produce a wavelength below 1100 nm. The device is configured to focus the laser beam to a full width at half maximum (FWHM) beam waist of 1-15 microns2 and a Rayleigh length of 6 microns or less, and the plasma is configured to be ignited by the CW laser beam.

A mode-locked solid-state laser apparatus having a resonator which includes a solid-state laser medium, a saturable absorption mirror, and a negative group dispersion element therein, in which the solid-state laser medium and the saturable absorption mirror are disposed at a distance not greater than twice a Rayleigh length which is determined by the beam radius of oscillation light formed at the saturable absorption mirror. The apparatus further includes a dichroic mirror in the resonator that reflects excitation light inputted from a direction crossing the optical axis of the resonator toward the solid-state laser medium and transmits oscillation light.

The invention discloses a system and method for generating teraHertz waves by using flight focusing, wherein the system for generating the teraHertz waves by using the flight focusing comprises a chirped signal generating device and a flight focusing device, wherein the chirped signal generating device is used for generating chirped laser pulse; the flight focusing device uses a diffraction element for focusing the chirped laser pulse so as to stimulate and generate air plasma and to further generate the teraHertz waves. The chirped laser pulse and the diffraction element are combined by the system and method for generating teraHertz waves by using flight focusing provided by the invention, so that the moving speed of the peak value intensity of the laser focus point region is controlled;the propagation of the laser light beams in the focusing regions can be controlled; in addition, the propagation length is many times of the Rayleigh length. Compared with the existing method for generating the teraHertz waves by the air, the method provided by the invention has the advantages that the intensity of the teraHertz waves generated by the method is greatly enhanced; the blank in the technical field of the existing high-intensity teraHertz wave generation is filled; high scientific research and practical application values are realized.

A distributed resonator laser system using retro-reflecting elements, in which spatially separated retroreflecting elements define respectively a power transmitting and a power receiving unit. The retroreflectors have no point of inversion, so that an incident beam is reflected back along a path essentially coincident with that of the incident beam. This enables the distributed laser to operate with the beams in a co-linear mode, instead of the ring mode described in the prior art. This feature allows the simple inclusion of elements having optical power within the distributed cavity, enabling such functions as focusing / defocusing, increasing the field of view of the system, and changing the Rayleigh length of the beam. The optical system can advantageously be constructed as a pupil imaging system, with the advantage that optical components, such as the gain medium or a photo-voltaic converter, can be positioned at such a pupil without physical limitations.

A system for correcting the wavefront of a laser beam includes a beamsplitter for splitting off a fraction of the laser beam to be used as a diagnostic beam, a focusing element for bringing the diagnostic beam to a focus, a measurement subsystem for measuring sizes of the diagnostic beam at upstream and / or downstream locations with respect to a nominal location of the focus, and at least one adaptive optic, located upstream from the beamsplitter, for correcting the wavefront of the laser beam at least partly based on the measured sizes of the diagnostic beam at the upstream and / or downstream locations. The upstream and downstream locations correspond to mid-field locations in the laser beam as imaged by the focusing element. The system takes advantage of the sensitivity of the laser beam size to a waist location shift being greatest at one Rayleigh length from the nominal waist location.

A mode-locking solid-state laser apparatus is a soliton-type mode-locking solid-state laser apparatus, having a solid-state laser medium, a saturable absorption mirror and a negative group velocity dispersion element in a resonator, wherein the solid-state laser medium and he absorption mirror are disposed at a distance not greater than twice a Rayleigh length. Then, the absorption modulation depth Delta R of the saturable absorption mirror is set to a value not less than 0.4%, and the absolute value lDl of a total intracavity dispersion amount when light having a predetermined wavelength makes one round trip in the resonator, which is represented by the following mathematic expression (1), is set within a pulse bandwidth in which operation modes other than a fundamental period soliton pulse can be suppressed by the saturable absorption mirror.

The invention relates to a mode-locked solid-state laser apparatus having a resonator which includes a solid-state laser medium, a saturable absorption mirror, and a negative group dispersion element therein, in which the solid-state laser medium and the saturable absorption mirror are disposed at a distance not greater than twice a Rayleigh length which is determined by the beam radius of oscillation light formed at the saturable absorption mirror. The apparatus further includes a dichroic mirror in the resonator that reflects excitation light inputted from a direction crossing the optical axis of the resonator toward the solid-state laser medium and transmits oscillation light.

There are many de-convolution algorithms (using Fourier transforms for example) that allow calculation of ki and Ri given the image values of I (xi, yi). The problem arises when the PSF's are closer together than a Rayleigh length: the number of artifact images (false images) available from a typical de-convolution algorithm may then be very large. Thus the overall probability of a false de-convolved image also is very large. This is the ambiguous image problem first identified by Toraldo di Francia (Reference 1). We solve this problem by finding the maximum in the Laplacian (i.e., take largest second derivative) along the isophote ridges on which the first derivative=0 (on a circle around the maximum). To correctly use this algorithm we must apply it to an off axis telescope.

In a soliton mode-locked solid-state laser apparatus having a resonator which includes therein a solid-state laser medium, a saturable absorption mirror, and a negative group velocity dispersion element, the solid-state laser medium and saturable absorption mirror are disposed in close proximity to each other at a distance not greater than twice a Rayleigh length. Then, the absorption modulation depth ΔR of the the saturable absorption mirror is set to a value not less than 0.4%, and the absolute value |D| (D<0) of a total intracavity dispersion amount D when light having a predetermined wavelength makes one round trip in the resonator, which is represented by the following relational expression, is set within a pulse bandwidth in which operation modes other than a fundamental period soliton pulse can be suppressed by the saturable absorption mirror.τP=1.76⁢D⁢λ0⁢AeffL,4⁢π⁢⁢n2⁢1⁢s⁢1EP

A frequency converter for converting a single-mode input beam at a fundamental frequency to an output beam at a converted frequency is configured with a plurality of phase-separated optical components defining a resonant cavity. The optical assembly shapes the input beam to have at least one beam waist within the cavity. The frequency converter also includes a nonlinear crystal located within the resonator in a diverging beam having a Rayleigh length less than the round-trip length of the resonator such that the center of the crystal is aligned with the beam waist along the beam path. separate, or the nonlinear crystal is located in a collimated beam whose Rayleigh length is greater than the resonator round-trip length.

The invention relates to the technical field of laser arc welding, in particular to a hybrid welding continuous welding method and device, a welded product, and a car body. The method of the present invention includes: performing composite welding on the groove of the weldment by coupling laser and polarity-changing arc; wherein, the defocusing amount of the laser is not less than the Rayleigh length of the laser. The method of the present invention effectively reduces the power density of the laser on the surface of the weldment, reduces the depth-to-width ratio of the weld, increases the diameter of the welded hole, effectively reduces the hole caused by the collapse of the welded hole, and further solves the problem of the prior art Welding porosity defects are difficult to escape, reduce the generation of hydrogen pores, effectively improve welding stability and reliability, and improve the mechanical properties of welds.

The invention relates to a preparation system and method for an ultraviolet nanosecond laser direct writing microfluidic chip. The microfluidic chip preparation system includes: an ultraviolet nanosecond laser, an electronically controlled aperture, a laser beam expander, a beam converter, and a beam Rotator, lens, dichroic mirror, laser cutting head, three-dimensional mobile platform and control device. The invention adopts a beam converter composed of a binary phase plate and an axicon lens, which can effectively generate smooth and high-quality first-class zero-order and long-Rayleigh The length of the Bessel laser can effectively erase the first-order aperture outside the zero-order light in the center of the zero-order Bessel beam, thereby effectively improving the processing quality of the Bessel beam. The invention can realize laser direct writing microfluidic chip processing with high aspect ratio, improve laser processing efficiency, and has simple system structure and easy operation, and can be used for high-efficiency and high-quality processing of microfluidic chips in various schemes.

A piercing processing method and a laser processing machine capable of carrying out a piercing processing on a thick plate in short time are provided. It is a processing method for carrying out a piercing processing on a metallic material by laser beams with wavelengths in 1 μm band, where the piercing processing is carried out by maintaining a range of 8≤Zr / d≤12 when a condensed beam diameter of the laser beams is set to be d and a Rayleigh length of the laser beams is set to be Zr. At that time, a focal position of the laser beams is set to be on a surface of a workpiece or an external of the workpiece. Then, a beam profile of the laser beams is such that the laser beams of a single mode are converted into a bowler hat shape by a beam quality tunable device.