Abstract: An optical fiber with wide bandwidth and high gain in an O+E band and a regulation method thereof are disclosed. The optical fiber includes a core and a cladding (0). The core includes a first loose layer (1), a first core layer (2), a second loose layer (3), a second core layer (4) and an inner core (5) from outside to inside. The first loose layer (1) and the second loose layer (3) are made of a silica material doped with high-refractive-index GeO2 and P2O5. In the first core layer (2) and the second core layer (4), Al2O3, bismuth oxide and PbO are sequentially doped. The gain performance of the optical fiber is controlled by adjusting doping molar ratios of Al2O3, bismuth oxide and PbO. The co-doped silica optical fiber maintains fiber gains exceeding 15 dB in a wavelength range of 1260 to 1460 nm.

Abstract: Disclosed are a system and a method for measuring a magnetorefractive effect of an optical fiber. The system comprises a laser, a coupler A, a sensing optical fiber, a reference optical fiber, a carrier generator, a coupler B, a photoelectric detector and a data acquisition and processing module. The coupler A, the sensing optical fiber, the reference optical fiber and the coupler B form a Mach-Zehnder optical fiber interferometer. An external magnetic field influences the refractive index of the sensing optical fiber, so that the optical path difference between two paths of optical signals in the sensing optical fiber and the reference optical fiber is changed, the intensity of an interference optical signal output by the coupler B is changed, and the refractive index change of the sensing optical fiber under the action of the magnetic field is measured by detecting and processing the interference optical intensity.

Abstract: Disclosed is an optical waveguide multi-cascaded coupling mode division multiplexer. The optical waveguide multi-cascaded coupling mode division multiplexer comprises an optical waveguide layer and a substrate layer, wherein the optical waveguide layer comprises a first optical waveguide and a second optical waveguide; the second optical waveguide comprises a transmission optical waveguide and a plurality of coupling structures; each coupling structure comprises a coupling optical waveguide and a connecting optical waveguide; the coupling optical waveguide and the transmission optical waveguide are connected through the connecting optical waveguide; the coupling optical waveguide is parallel to the transmission optical waveguide; and the distance between the coupling optical waveguide and the first optical waveguide is smaller than that between the transmission optical waveguide and the first optical waveguide.

Abstract: A quantum-dot-based measuring system is disclosed. The quantum-dot-based measuring system includes a laser to emit excitation light, an optical fiber probe including a tail end and a tapered tip, and the tapered tip of the optical fiber probe is attached with one or more quantum dots, and the excitation light is injected from the tail end of the optical fiber probe and emitted from the tapered tip to a sample to be detected, an objective lens to collect optical signal reflected by the sample and a spectrometer to receive the optical signal.

Abstract: Disclosed are a system and a method for measuring a magnetorefractive effect of an optical fiber. The system comprises a laser, a coupler A, a sensing optical fiber, a reference optical fiber, a carrier generator, a coupler B, a photoelectric detector and a data acquisition and processing module. The coupler A, the sensing optical fiber, the reference optical fiber and the coupler B form a Mach-Zehnder optical fiber interferometer. An external magnetic field influences the refractive index of the sensing optical fiber, so that the optical path difference between two paths of optical signals in the sensing optical fiber and the reference optical fiber is changed, the intensity of an interference optical signal output by the coupler B is changed, and the refractive index change of the sensing optical fiber under the action of the magnetic field is measured by detecting and processing the interference optical intensity.

Abstract: The invention discloses a preparation method and device of active microcrystalline fiber, place the prefabricated rod in the drawing furnace for wire drawing, the drawn fiber is induced by magnetic field in uncoated state and combined with laser treatment technology, the laser beam is focused on the fiber and recrystallized after laser treatment to obtain active microcrystalline fiber. Appropriate laser processing power directly affects the silicate glass fiber in the crystal structure, type, degree of crystallinity, grain size, content, and how much residual phase of glass. Induced by external magnetic field, the thermodynamics and dynamics of crystallization process are changed, make the crystal size distribution is better and uniform, reduce the phenomenon of condensation and makes the grain size is smaller.

Abstract: The invention discloses a preparation method and device of active microcrystalline fiber, place the prefabricated rod in the drawing furnace for wire drawing, the drawn fiber is induced by magnetic field in uncoated state and combined with laser treatment technology, the laser beam is focused on the fiber and recrystallized after laser treatment to obtain active microcrystalline fiber. Appropriate laser processing power directly affects the silicate glass fiber in the crystal structure, type, degree of crystallinity, grain size, content, and how much residual phase of glass. Induced by external magnetic field, the thermodynamics and dynamics of crystallization process are changed, make the crystal size distribution is better and uniform, reduce the phenomenon of condensation and makes the grain size is smaller.

Abstract: Disclosed is a method for fabricating a spherical concave mirror in an optical waveguide based on ultraviolet (UV) grayscale lithography. A key component is a specially designed mask pattern composed of a rectangle as well as a semicircle adjacent to the rectangle, where a rectangular area has no grayscale distribution, and UV light penetrating through different portions of the rectangular area has the same intensity; a semicircular area has the grayscale distribution, and the UV light penetrating through the semicircular area with the grayscale distribution is changed in intensity from the center of a circle in the radius direction according to a special function distribution law; an interlayer photoresist in the rectangular area is irradiated by the UV light penetrating through a mask plate and is developed to form an optical waveguide core.

Abstract: A quantum-dot-based measuring system is disclosed. The quantum-dot-based measuring system includes a laser to emit excitation light, an optical fiber probe including a tail end and a tapered tip, and the tapered tip of the optical fiber probe is attached with one or more quantum dots, and the excitation light is injected from the tail end of the optical fiber probe and emitted from the tapered tip to a sample to be detected, an objective lens to collect optical signal reflected by the sample and a spectrometer to receive the optical signal.

Abstract: Disclosed is a method for fabricating a spherical concave mirror in an optical waveguide based on ultraviolet (UV) grayscale lithography. A key component is a specially designed mask pattern composed of a rectangle as well as a semicircle adjacent to the rectangle, where a rectangular area has no grayscale distribution, and UV light penetrating through different portions of the rectangular area has the same intensity; a semicircular area has the grayscale distribution, and the UV light penetrating through the semicircular area with the grayscale distribution is changed in intensity from the center of a circle in the radius direction according to a special function distribution law; an interlayer photoresist in the rectangular area is irradiated by the UV light penetrating through a mask plate and is developed to form an optical waveguide core.

Abstract: Provided are an optical coupling device and an optical coupling unit including the optical coupling device. The optical coupling device includes a right-angle reflecting prism (23) and a mobile optical fibre connector (21). A reflecting surface of the right-angle reflecting prism (23) is provided with a curve reflecting surface (24), the curve reflecting surface being used for gathering and reflecting rays propagated by an optical fibre. The mobile optical fibre connector (21) is fixed to the right-angle reflecting prism (23), to make the rays propagated by the optical fibre being incident on the curve reflecting surface (24) of the right-angle reflecting prism (23).