Describe briefly how half-wave and quarter wave want) b) if an (difference between "fast" and "slow" axes) is 105 for a material with n=1.5, calculate the minimum thickness of a 2 and wave plate for light with a wavelength 500nm. these are called "zero-order" waveplates c) zero-order waveplates are often difficult to make because they are very thin. to make it thicker and easier to manufacture, plates work (using diagrams if you we can make the optical path difference (n 1/2)a for a half wave plate and (n 1/4) a for a quarter wave plate, where n is any integer. if n 5 what are the new thicknesses for the waveplates? d) waveplates clearly do not work properly for all wavelengths. for b) (zero order waveplates) calculate the wavelength that i) the half waveplate would turn into a quarter waveplate e) do the same for the multiple order half waveplate and make a conclusion about the useable wavelength ranges for the zero-order compared to the multiple order waveplates 4. fiber bragg gratings a fiber bragg grating is written in a fiber (n-1.5) with a strength cm at -1550nm a) what is the bandwidth of the grating in nm? b) what is the reflectivity (in %) and transmission (in db)? c) if this grating were written in birefringent fiber where the diference in refractive index for the two polarizations, an 103, what is the separation in grating wavelengths for the two polarizations? d) will this grating be any good for filtering unpolarized light? k 2cm and length l- 2 5. optical data storage cd players use new blu-ray disc players use na0.85, - 405nm. a) what is the spot size for cd players b) what is the spot size for bluray players (use same formula as i) c) calculate the ratio of the focal spot area for the blu-ray disc player compared to cds (ie., ratio a bluray /a cd) d) assuming that the total information on the disc scales inversely with spot area, what would this predict for the number of gigabytes for a bluray disc (cd roms 700mb (1 mb 1 million bytes)? e) is the spot-size reduction itself enough to explain the increased data storage of bluray discs? objective with na= 0.45, and laser wavelength -780nm, whereas the an are f) what else could account for the difference?