Optics and Photonics Technology EEE4127 Example sheet – week 1 – The Nature of Light (1)(a) Name two optical instruments, briefly describe their use and most important optical feature. (b) Name two everyday optical devices, briefly explain what they do and their most important feature(s) (2) (a) Name 3 mass market consumer optical technologies: (2) (b) Name 3 high spec optics instrument technologies: (3) Name 3 non science applications or uses for cameras (4) Ambient lighting in a room is around 1W/m^2 On average how much light falls on each pixel of your smart phone camera when you take a picture How many photons is that What’s the minimum SNR that your image has at that light level (5) Name three models for describing light and explain when they are used: (6) What model of light is usually used for lens design (7) Give and example of a problem where an electromagnetic wave description of light is required to model a system (8) The refractive index of perspex is 1.49 at 600nm, is the speed of light in the perspex faster or slower than the speed of light in water A beam of light travels
from air to perspex to water, in which substance does it have the longest and shortest wavelengths In which substance does it have the highest frequency (9) Give examples of optical wavelengths in the UV, visible and IR parts of the spectrum (10) For a typical laser and a typical light bulb which devices produces the widest optical spectrum (11) Name one phenomena of coherent light that isn’t a property of incoherent light (12) What does the imaginary part of the refractive index mean (13) Why does light have “polarisation” (14) What wavelengths correspond to the visible / UV / IR parts of the EM spectrum (15) What’s the energy carried by a visible / UV / IR photon (16) Name two conditions for light to travel in a “straight line” (17) Name two things that might happen to light when it travels from one refractive index to another (18) A Crooke’s Radiometer has vanes painted black on one side and white on the other. The vanes can turn freely and are enclosed in a partial vacuum. When illuminated they turn with the white side coming forward. What does this tell you about radiation pressure