Abstract: Disclosed is a small-diameter polarization maintaining optical fiber, which relates to the field of special optical fibers. The small-diameter polarization maintaining optical fiber comprises a quartz optical fiber (5); the periphery thereof is provided with an inner coating (6) and an outer coating (8); the interior of the quartz optical fiber (5) is provided with an optical fiber core layer (1) and a quartz cladding (2); two stress zones (4) are arranged between the optical fiber core layer (1) and the quartz cladding (2); a buffer coating (7) is arranged between the inner coating (6) and the outer coating (8); the periphery of each stress zone (4) is provided with a buffer layer (3) which is concentric with the stress zone (4); when a working wavelength of a small-diameter polarization maintaining optical fiber is 1310 nm, the attenuation thereof reaches less than 0.

Abstract: Disclosed is a small-diameter polarization maintaining optical fiber, which relates to the field of special optical fibers. The small-diameter polarization maintaining optical fiber comprises a quartz optical fiber (5); the periphery thereof is provided with an inner coating (6) and an outer coating (8); the interior of the quartz optical fiber (5) is provided with an optical fiber core layer (1) and a quartz cladding (2); two stress zones (4) are arranged between the optical fiber core layer (1) and the quartz cladding (2); a buffer coating (7) is arranged between the inner coating (6) and the outer coating (8); the periphery of each stress zone (4) is provided with a buffer layer (3) which is concentric with the stress zone (4); when a working wavelength of a small-diameter polarization maintaining optical fiber is 1310 nm, the attenuation thereof reaches less than 0.

Abstract: A method is provided for predicting that a patient will require a blood transfusion during a treatment. The method includes obtaining, on a processor, first data that indicates values for one or more parameters of a characteristic of a continuous photoplethysmographic (PPG) waveform collected during the treatment. The method further includes applying, on the processor, coefficients to the values for the one or more parameters. The method further includes determining, on the processor, second data that indicates a prediction that the patient will require the blood transfusion during the treatment based on applying the coefficients to the values for the one or more parameters. An apparatus is also provided for predicting that the patient will require the blood transfusion during the treatment.

Abstract: A large mode field active optical fiber and manufacture method thereof is provided. The large mode field active optical fiber is formed by drawing a fiber core (1), a quartz glass internal cladding (2), a quartz glass outer cladding (3), and a coating (4). The quartz glass internal cladding (2), the quartz glass outer cladding (3), and the coating (4) are sequentially coated on the outer surface of the fiber core (1). The fiber core (1) is formed by depositing, melting, and shrinking the tetrachlorosilane doped with rare earth ions in a quartz glass tube. The refractive index of the fiber core (1) is a graded refractive index, and the section parameter a thereof is 1???3. The appearance of the quartz glass inner cladding (2) is regular multi-prism shaped.

Abstract: A large mode field active optical fiber and manufacture method thereof is provided. The large mode field active optical fiber is formed by drawing a fiber core (1), a quartz glass internal cladding (2), a quartz glass outer cladding (3), and a coating (4). The quartz glass internal cladding (2), the quartz glass outer cladding (3), and the coating (4) are sequentially coated on the outer surface of the fiber core (1). The fiber core (1) is formed by depositing, melting, and shrinking the tetrachlorosilane doped with rare earth ions in a quartz glass tube. The refractive index of the fiber core (1) is a graded refractive index, and the section parameter a thereof is 1???3. The appearance of the quartz glass inner cladding (2) is regular multi-prism shaped.