Abstract: According to one embodiment of a system for measuring differential mode delay couples with a pulse generator to generate an input electrical pulse, a photo detector to receive optical pulse from an optical fiber, and a digital oscilloscope to receive an output electrical pulse transmitted from the photo detector, the system includes: a laser diode, a first lens and a second lens, a pigtail, and a spliced optical connector, wherein the laser diode receives the input electrical pulse to produce a laser beam, the first lens and the second lens focus the laser beam into the pigtail, the spliced optical connector connects the pigtail and the input end face of the optical fiber such that the optical pulse from the output end face of the optical fiber is received by the photo detector.

Abstract: A manufacturing method of forming undertone layer of optical fiber with single-layer coating is provided. The optical fiber with single-layer coating includes, from the center outwards, glass core, cladding layer (outer diameter 80 um-125 um) and permanent coating (thickness 4 um-8 um). The method of forming undertone layer over permanent coating includes: placing optical fiber in a coloring machine so that coloring machine guiding optical fiber moving forwards, coloring machine having at least a mask device and a UV curing device; coating an undertone layer on permanent coating of optical fiber when optical fiber passing mask device, the thickness of undertone layer being 3-200 um; irradiating UV onto optical fiber passing UV curing device to solidify the undertone layer on permanent layer; and coloring machine collecting processed optical fiber, the coating strip force of undertone layer of optical fiber being less than 1 Newton.

Abstract: A connection module is provided, including a shell. The shell has formed at least a guiding hole, at least a fiber optical guiding trench on a shell of the module, and a window located inside the shell at the end of fiber optical guiding trench. The guiding hole is located on one side of the shell for fiber optical to enter the shell through the guiding hole. The fiber optical guiding trench is located inside the shell to guide the fiber optical for large angle turns so that the front end of the fiber optical can reach the window. The connection module can be placed on top to cover an optical transceiving area. The optical transceiving area includes at least a point optical source or a receiver so that the optical signals at the optical transceiving area can be transmitted to outside.