Question

QUESTION 1 1.1 In any long-haul optical fibre communications channel, it is important to have a large Bandwidth-Length Product (Hz-km). Name 4 things that could be considered in order to increase the Bandwidth-Length Product of a specific length of optical fibre. (4) 1.2 An optical fibre has a core diameter of 9 um and a refractive index of 1.466. The cladding refractive index is 1.442. 1.2.1 Determine if the fibre will permit single mode transmission at a wavelength of 1320 nm. (2) 1.2.2 Estimate the range of wavelengths over which the fibre will be single mode. (4)

Answer 1

of Bandwidth depends on type of fiber, wave length and source line width and A Heunation, depends on on Atleunation, Depression, Mode field Diameter length CSScanned with CamScanner

Given core refractive index (7.) = 1.466 cladding refractive index (N 2 ) = 1-442 :v core diameter = 0 : quemet operating ware length 1) = 1320nmet V wave Normalized frequency.ois gives is in fomation about Cutoff values of certain parametersi-like , loperating length etc. * In order to operate the optical fiber in Singles mode the Normalized frequency (V) 2.405 . At V=204.05 optical fiber operates in Single Mode. V = 2XITXQ [Nin] (a=) 'a: Core radius of fiber de operating ware length csscanned with Na Aseannblumerical aperture 기 2 n

Step 2: Substitute all given values in equation @ and check vis less than 2.405 V: 2 x TT X 4,5x10-6 XV104662-74422 = 5.65 1320 X10-9 V = 5.65 Wave than 2-405. So. suitable for given Step 2:- To find o gro Obtain value for Normalized frequency V.is greater length is not not single Mode operation for range of wavelength operation in Single Mode equate sy take, value of V = 214057 Step 3: calculate the value of operating ware' lengte(A) for this value of v. in equation ® 2 19.[NIA] V = 2ta d da V 2 IT a [Non de 2x1x 4.5x18 6 х J 1.466²_14442 2: 405 d = 3-10x10-6 met 1 de =301 remet So, wave wave lengths lengths above tkis 3.1 Mmet, coil' travel in single mode. CS$canned with Camglamngo 1 Mmet is range for single mode operations