3 results about "Nanosecond" patented technology

A laser light source comprises a semiconductor laser adapted for pulsed operation, a partially transmitting wavelength selective light reflector. The semiconductor laser comprises a front facet and a back facet. The front facet and the back facet define an internal laser cavity. The internal laser cavity comprises a laser active medium. The partially transmitting wavelength selective light reflector has a peak reflectivity within a gain bandwidth of said laser active medium. The wavelength selective light reflector and the back facet define an external laser cavity. A roundtrip time of light in the external laser cavity is about 20 nanoseconds or less. A full width half maximum bandwidth of the wavelength selective light reflector is adapted to accommodate at least 12 longitudinal modes of the internal laser cavity and at least 250 longitudinal modes of the external laser cavity.

The invention discloses a non-contact detection method for detecting the elastic parameter uniformity of a material on line. A non-contact real-time characterization method is used for the elastic parameters of a solid material, and comprises the steps of: (1) radiating pulse laser to a spatial modulator, generating two beams of coherent light after the pulse laser passes through the spatial modulator; wherein the laser source is a nanosecond or a picosecond pulse light source, the pulse light is split through the spatial modulator consisting of gratings, and the +/- level serves as a coherent light source; (2) radiating the two beams of coherent light to the surface of the tested material and generating spatial coherent interference field by utilizing an optical component lens group, forming alternately dark and bright interference fringes on the surface of the tested material, wherein the distance between the alternately dark and bright interference fringes is acquired by adjusting the lens group or the gratings; and (3) generating sound waves of which the wavelength corresponds to the distance between the interference fringes in a thin-film material after the interference fringes formed by the pulse light source are absorbed by the thin-film material, and performing non-contact detection for characterizing and analyzing the elastic parameters of the solid sample.

The invention discloses a laser marking method safe for human eyes, which is characterized in that an all-fiber laser with the optical wavelength between 1.52 microns and 1.59 microns is provided, pulse laser is output by the all-fiber laser, the pulse laser is irradiated to a workpiece to be processed after being amplified and focused, and laser marking is realized through relative movement of a focusing position and the workpiece to be processed; wherein the pulse laser is composed of pulse trains, each pulse train comprises 2-6 pulses, the pulse width of each pulse is smaller than 10 picoseconds, the interval between every two adjacent pulses is smaller than 50 nanoseconds, one million to ten million pulse trains are included per second, and finally output single pulse energy is not larger than 100 nanojoule. The laser adopted by the invention has a high damage threshold to human eyes, and can be suitable for surface marking of metal materials, composite materials, transparent materials, organic materials and the like.