Apparatus and methods for improved HHG of ultrashort pulse laser beams. A HHG assembly includes a gas distribution block and a waveguide cartridge having a HHG hollow core waveguide. The waveguide cartridge is attached to the gas distribution block and may be removed and replaced, while the gas distribution block remains affixed within the apparatus. The gas distribution block is configured to maintain a pressure profile within the hollow core fiber. The system also includes two operating beam sensors and two actuatable mirrors. The operating beam sensors are fixed with respect to the HHG assembly. The system is aligned before operation by adjusting the actuatable mirrors to optimize a sample beam through the waveguide and recording the position of the beam on the operating beam sensors. In operation, the mirrors are actuated to maintain the same positions of the input beam on the operating beam sensors.

Apparatus and methods for improved HHG of ultrashort pulse laser beams. A HHG assembly includes a gas distribution block and a waveguide cartridge having a HHG hollow core waveguide. The waveguide cartridge is attached to the gas distribution block and may be removed and replaced, while the gas distribution block remains affixed within the apparatus. The gas distribution block is configured to maintain a pressure profile within the hollow core fiber. The system also includes two operating beam sensors and two actuatable mirrors. The operating beam sensors are fixed with respect to the HHG assembly. The system is aligned before operation by adjusting the actuatable mirrors to optimize a sample beam through the waveguide and recording the position of the beam on the operating beam sensors. In operation, the mirrors are actuated to maintain the same positions of the input beam on the operating beam sensors.

A method for generating ultrashort pulses includes directing a master beam having ultrashort pulses and at least one slave beam through an optical gate material. The intensity of the slave beam upstream of the optical gate material is lower than that of the master beam upstream of the optical gate material. The optical gate material and the pulses of the master beam are chosen to induce a Kerr effect when the master beam passes through the optical gate material, the Kerr effect producing a modulation of the phase of the slave beam in association with pulses of the master beam when the slave beam passes through the optical gate material. The modulation of the phase of the slave beam is transformed into a modulation of the amplitude thereof using a complementary optical device to generate a slave beam downstream of the optical gate material having ultrashort pulses.

An object is to provide, for example, an optical wavelength conversion device capable of highly efficient wavelength conversion on the surface of, or inside, the main body of any of various shapes, such as a bulky shape and a fiber shape. The optical wavelength conversion device includes a main body configured to allow light to propagate therein, and a plurality of crystal regions arranged inside the main body along a propagation direction of the light. The plurality of crystal regions each have a spontaneous polarization oriented along the propagation direction (i.e., spontaneous polarization having a polarization orientation coinciding with the propagation direction).

An optical wavelength converter of one embodiment comprises: a substrate comprised of a crystalline material or an amorphous material; plural first crystal regions each having a radial first polarization-ordered structure; and plural second crystal regions each having a radial second polarization-ordered structure. In the substrate, a first and second regions are defined to be directly adjacent to each other with a virtual axis therebetween when the substrate is viewed from a reference direction orthogonal to the virtual axis. Radial centers of the first polarization-ordered structures located in the first region and radial centers of the second polarization-ordered structures located in the second region are alternately arranged along the virtual axis. The plural first crystal regions partially protrude to the second region. The plural second crystal regions partially protrude to the first region.

An object is to provide, for example, a method for manufacturing an optical wavelength conversion device having a structure that enables efficient formation of crystal regions on the surface of, or inside, an amorphous material. An amorphous main body is intermittently irradiated with a first laser beam for generating a high-density excited electron region inside the main body and a second laser beam for heating the high-density excited electron region, with respective focus regions of the first and second laser beams overlapping each other. During the intermittent irradiation with the first and second laser beams, the relative position of the main body and the overlapping focus region of the first and second laser beams are varied. This enables part of the main body where the overlapping focus region moves to serve as a heat source for forming a crystal region.

An object is to provide, for example, a method for manufacturing an optical wavelength conversion device having a structure that enables efficient formation of crystal regions on the surface of, or inside, an amorphous material. An amorphous main body is intermittently irradiated with a first laser beam for generating a high-density excited electron region inside the main body and a second laser beam for heating the high-density excited electron region, with respective focus regions of the first and second laser beams overlapping each other. During the intermittent irradiation with the first and second laser beams, the relative position of the main body and the overlapping focus region of the first and second laser beams are varied. This enables part of the main body where the overlapping focus region moves to serve as a heat source for forming a crystal region.

An object is to provide, for example, a method for manufacturing an optical wavelength conversion device having a structure that enables efficient formation of crystal regions on the surface of, or inside, an amorphous material. An amorphous main body is intermittently irradiated with a first laser beam for generating a high-density excited electron region inside the main body and a second laser beam for heating the high-density excited electron region, with respective focus regions of the first and second laser beams overlapping each other. During the intermittent irradiation with the first and second laser beams, the relative position of the main body and the overlapping focus region of the first and second laser beams are varied. This enables part of the main body where the overlapping focus region moves to serve as a heat source for forming a crystal region.

A display screen, a pair of glasses, a display system and a playing method are provided. The display screen includes a display control module and a display panel. The display control module controls the display panel to display multiple frames of images according to multiple predetermined playing codes. Each playing code corresponds to one frame of image. Each frame of image is displayed as normal image or interference image based on different logic values of the corresponding playing code. The multiple frames of images are divided into multiple consecutive frame groups. The quantity of consecutive frames corresponding to playing codes having an identical logic value in each frame group is not larger than a predetermined value, such that a user wearing glasses matching the display screen can see the normal images displayed on the display panel and cannot see the interference images displayed on the display panel.

In one aspect, a method is provided for generating supercontinuum laser pulses within a continuous mid-infrared spectral range in a chalcogenide material. This method includes focusing an input laser beam of femtosecond pulses with a pulse energy higher than 10 microjoule along an optical path of the input laser beam; placing a chalcogenide material at a selected location along the optical path of the laser beam so that the laser intensity at the chalcogenide material is sufficiently high to cause nonlinear optical absorption that causes conversion of input optical energy into supercontinuum laser pulses of a pulse energy at or above a microjoule level at optical wavelengths within a broad continuous mid-infrared spectral range without damaging the chalcogenide material; and simultaneously moving the chalcogenide material laterally relative to the input laser beam to avoid damage to the chalcogenide material.