5.
    发明专利
    未知

    公开(公告)号:DE949518T1

    公开(公告)日:2000-04-20

    申请号:DE99106984

    申请日:1999-04-09

    Abstract: A grating (10) made in the core of an optical fibre (1) presents a non-uniform and asymmetrical profile of the modulation of the refractive index in the direction of the length, which profile is represented by a curve that rises gradually and monotonically from a minimum and substantially null value, with substantially horizontal tangent, in correspondence with an end of the grating (10), until a maximum value, also with substantially horizontal tangent, which is reached in correspondence with the other end of the grating (10).

    Method of and Device for Measuring the Refractive Index of Wafers of Vitreous Material

    公开(公告)号:CA2173564A1

    公开(公告)日:1996-10-06

    申请号:CA2173564

    申请日:1996-04-04

    Inventor: TALLONE LUIGI

    Abstract: A light beam is sent on a wafer (4), at different angles of incidence, thus giving rise to fluctuations in the transmittance of the wafer, as the angle of incidence varies, because of interference due to multiple reflections of the beam inside the wafer (4). The transmittance of the wafer (4) is measured as the angle of incidence varies; the angular positions of transmittance maxima and minima are determined with respect to a maximum or minimum corresponding to normal incidence, and the refractive index is obtained from these positions and from the number of maxima and minima in the different angles. The device performing the method is also provided.

    10.
    发明专利
    未知

    公开(公告)号:IT1249939B

    公开(公告)日:1995-03-30

    申请号:ITTO910492

    申请日:1991-06-28

    Abstract: The radiation to be analysed is sent onto an interference filter (6) which selects different portions of the radiation spectrum in correspondence with different incidence angles. The intensity values of the radiation outgoing from the element (6) are stored by a measuring and data processing unit (9) which processes such values with the transfer function of the element to obtain the information on the spectrum.

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