Category: Part 5: Optics
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Problem 5.181 — Diffraction: Rectangular Aperture
Problem Statement Solve the oscillation/wave problem: A rectangular aperture ($a = 0.5$ mm wide, $b = 1.0$ mm tall) is illuminated by a plane wave ($\lambda = 500$ nm). A lens ($f = 1.0$ m) focuses the diffraction pattern. Find the dimensions of the central maximum. The central maximum extends to the first minima in…
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Problem 5.182 — Laser Speckle Size
Problem Statement A laser beam ($\lambda = 633$ nm) illuminates a rough surface of diameter $D = 20$ mm. A screen is placed $L = 1.0$ m away. Estimate the average speckle size. Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts…
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Problem 5.179 — Photonic Crystal: Stop Band
Problem Statement Solve the quantum/modern physics problem: Solve the quantum/modern physics problem: A 1D photonic crystal has alternating layers of $n_1 = 1.5$ (thickness $d_1 = 100$ nm) and $n_2 = 1.0$ (thickness $d_2 = 150$ nm). Estimate the centre wavelength of the first stop band at normal incidence. For a quarter-wave stack condition: $n_1…
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Problem 5.180 — Etalon as Spectrum Analyser
Problem Statement A Fabry-Perot etalon ($d = 5$ mm, $n = 1.5$, $R = 0.95$) is used to analyse the spectrum near $\lambda = 500$ nm. Find the free spectral range, finesse, and minimum resolvable linewidth. Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics principles…
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Problem 5.178 — Mueller Matrix for Polarizer
Problem Statement Write the Mueller matrix for an ideal linear polarizer with transmission axis at $\theta = 0°$ (horizontal), and find the Stokes vector of the output when the input is $(S_0, S_1, S_2, S_3) = (1, 0, 0, 0)$ (unpolarized). Given Information See problem statement for all given quantities. Physical Concepts & Formulas This…
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Problem 5.176 — Scattering Cross Section
Problem Statement The Rayleigh scattering cross section of an air molecule at $\lambda = 500$ nm is approximately $\sigma = 5\times10^{-31}$ m². The number density of air at STP is $n = 2.69\times10^{25}$ m$^{-3}$. Find the scattering mean free path. Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem…
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Problem 5.177 — Atmospheric Extinction
Problem Statement Blue light ($\lambda_B = 450$ nm) and red light ($\lambda_R = 650$ nm) pass through an atmosphere of optical depth $\tau_B$ and $\tau_R$. Using $\tau \propto \lambda^{-4}$, find the ratio of transmitted intensities $I_B/I_R$ if $\tau_R = 0.10$ at zenith and the path is at zenith angle $z = 60°$. Given Information See…
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Problem 5.175 — Grating: Echelle Spectrograph
Problem Statement An echelle grating (300 lines/mm, blaze angle $\gamma = 63°$) is used near order $m = 50$ for $\lambda = 500$ nm. Find the angular dispersion and resolving power (grating width $W = 100$ mm). Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem applies fundamental physics…
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Problem 5.174 — Slit Source and Fraunhofer Pattern Width
Problem Statement A slit of width $a = 0.3$ mm is illuminated by a mercury lamp filtered to $\lambda = 546$ nm. A lens of focal length $f = 60$ cm focuses the Fraunhofer pattern. Find the full width of the central maximum and the positions of the first secondary maxima. Given Information See problem…
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Problem 5.172 — Photometry: Luminous Efficiency Spectrum
Problem Statement The photopic luminous efficiency function peaks at $\lambda = 555$ nm with $V(555) = 1.0$ and has $V(450) = 0.038$, $V(650) = 0.107$. A lamp emits equal radiant flux at all three wavelengths. Find the relative luminous fluxes. Given Information See problem statement for all given quantities. Physical Concepts & Formulas This problem…