1 / 12

METR 415/715

METR 415/715. Monday 2/4/2013. EM Radiation can be considered as particles as well as waves. Small “packets” ot EM radiation that behave like particles Called “photons” E= Energy carried by photon h= Planck’s constant = 6.626 X 10 -34 J s ν = Frequency. Photon’s are “indivisible”.

stefano-carton
Download Presentation

METR 415/715

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. METR 415/715 Monday 2/4/2013

  2. EM Radiation can be considered as particles as well as waves • Small “packets” ot EM radiation that behave like particles • Called “photons” • E= Energy carried by photon • h= Planck’s constant = 6.626 X 10-34J s • ν = Frequency

  3. Photon’s are “indivisible” • As text states on page 31 “very low intensity light deposits discrete packets of energy on a surface in a manner analogous to the occasional random splashes of fat raindrops on your windshield” • If monochromatic radiation of wavelegthλ deposits F Watts per unit area on a surface, then this corresponds to F/hν photons per unit area per unit time

  4. Flux (F) • Flux is the rate at which radiation is incident on, or passes through a flat surface • Expressed in units of Wm-2 for “broadband” radiation (radiation of many wavelengths) • The flat surface may be oriented in any direction • Monochromatic flux (Fλ) has units of Wm-2 per unit wavelength, Wm-2μm-1

  5. Broadband Flux • Encompasses a range of wavelengths. Defined as

  6. Intensity • Tells you in detail both the strength and the direction of various sources contributing to the incident flux on a surface • Spherical coordinates are useful in describing intensity • Coordinates are Φ (azimuth) and θ (elevation)

  7. Solid angle • Measured in steradians (sr) • Steradian – (ratio of area in a solid angle compared to the area of a sphere of unit radius) 4π r2, where r=1 • In differential form, a steradian would be:

  8. Reflection refraction scattering

  9. Refraction of light in a raindrop

  10. Scattering

  11. Reflectivity of water

  12. Absorption • “Imaginary” part of the index of refraction • Gives you information on how much absorption will take place

More Related