It is an important way to effectively improve applied optics experimental teaching effect and motivate the undergraduates’ practice ability and creativity by means of scientific and systematic setting teaching contents and link. Based on the research and analysis of applied optics experiment teaching present condition at home and abroad, this paper aims to solve the existed problems and deficiencies during the experiment teaching in our university, and also puts forward some reform ideas and practice method from several aspects such as teaching thought, teaching content and mode, examination and evaluation and so on. Simultaneously, this paper also gives some suggestions on the future course development.
Long period fiber grating is a kind of transmission type optical fiber grating. Due to the advantages such as low insertion loss, wide bandwidth, low-level reflection, high sensitivity, low cost and ease of compactness, LPFGs have been widely applied in optical fiber sensing and optical fiber communication. The Mode coupling of LPFG is the coupling between the fiber core mode and the cladding mode in the same transmission direction. If the ordinary LPFG is combined with bitaper or taper, we can effectively change the original LPFG's transmission spectrum to obtain the composite LPFG, which can stimulate new resonant peaks in the original wavelength-dependent transmission loss of the grating basis, thus applying to the dual-parameter simultaneously measuring field. We report a novel all-fiber narrow-bandwidth intermodal Mach– Zehnder interferometer (MZI) based on a long-period fiber grating (LPFG) combined with a fiber bitaper. The LPFG is written by high-frequency CO2 laser pulses, and the bitaper is connected in series with the LPFG, forming the Mach– Zehnder interferometer (MZI). Experimental results indicate that the MZI has good temperature sensitivity, The temperature sensitivity of the two loss peaks are 55.35pm/°C and 48.18pm/°C respectively. The strain sensitivity of the two loss peaks are 3.35pm/με and -4.925pm/με respectively. By using the different temperature and strain response characteristics of the loss peaks, the temperature and strain measurement can be realized simultaneously. the proposed device has good repeatability and stability, which would be a promising candidate for precise dual-parameter sensing application.
A series of LiNbO3:Hf:Ce:Cu crystals with various level of Hf doping were prepared using the Cz equipment with a resistance furnace. The crystal storage properties with optical damage resistance ability, sensitivity and dynamic range were measured by means of two-beam coupling light path. The defect structure is also discussed, accounting for the optical damage resistance. Based on optimal one of these crystals as storage medium, one thousand of holograms were recorded in a public coherent volume of 0.073 cm3. The result shows that storage density arrives10.7Gbits/cm3 and the crystal has potential application in the future high density storage..
we design a novel core-suspended capillary fiberhat the core is suspened in the air hole and close to the inner surface of the capillary, and experimentally demonstrate its fabrication technology. In addition, a method for linking a single mode fiber and a core-suspended fiber is proposed based on splicing and tapering at the fusion point between the two fibers. By combining with the optical time domain reflectometer technology, we construct a distributed gas sensor system to monitor greenhouse gas based on this novel fiber.
As the special core structure of the helical-core fiber, it has high fabrication difficulty. It has a high precision of
fabrication system requirement. The coaxality of optical fiber rotation is one of the key technologies. Under the premise
of a helical-core fiber fabrication system designed and manufactured, this paper puts forward micro-imaging test method
based on the centroid method. This method gets the image of fiber core spot through the microscopic imaging system,
and calculates the energy center of the spot image by using the centroid method. Thus we get the center and radius of
rotation of the spot image after the fabrication system rotated a period. Thereby the testing and adjustment of the
fabrication system coaxality are realized. The experimental results show that this method can complete the coaxality
testing of helical-core fiber fabrication system; make offset of the core be less than 10 μm. This method solves the
disalignment problem of optical fiber rotation during the process of helical-core fiber fabrication well.
A series of Sc:Ce:Cu: LiNbO3 crystals with various level of Sc doping were prepared using the Cz equipment with a
resistance furnace. The crystal storage properties with optical damage resistance ability, sensitivity and dynamic range
were measured by means of two-beam coupling light path. The defect structure is also discussed, accounting for the
optical damage resistance. Based on optimal one of these crystals as storage medium, one thousand of holograms were
recorded in a public coherent volume of 0.082 cm3. The result shows that storage density arrives10 Gbits/cm3 and the
crystal has potential application in the future high density storage.