Lecture 1 Flashcards
what are the properties of light
light carries electric and magnetic field
light has a frequency and this a wavelength and thus carries energy
momentum
polarized
coherence
interact w gravity
interact w itself
light formulas
c=lambda*v
E=hv=hc/lambda
p=E/c
gauss law of electric charges
electric fields are generated by single charges and diverge
gauss law of magnetism
magnetic fields are generated by dipoles abd dont originate from a single point
faradays law (induction)
a spatially varying field is accompanied by a temp varying mag field and vice versa
amperes law
mag fields are generated either by electric currents and/or changing electric fields
how does em theory describe light
-em force
-self-prop of light is due to electric and magnetic wave varying in unison
-major forces of em theory are: electrostatic forces and magnetic force
light as an EM wave?
-self-prop of light is due to electric and magnetic wave varying in unison
-light is imparted in unit called photon
-amt of energy of photon is relative to frequency
Lorentz or Em force
measures force exerted on a charged particle moving through an electric or magnetic field
F=qE+qv x B
E-electric field
B-magnetic field
how is light generated?
-from heat source (thermal radiation)
-from emission spectrum of transluscent material interacting w specific spectrum of light
radioactive heat loss
Pnet=Pemit-Pabsorb
Pnet=A(sigma)(heat emissivity)(T4-To4)
what makes lasers diff than normal light sources and main applications
monocromatic,polarized,directional, and coherent
communications,printing,cutting materials. barcode and LASIK
thermal effect related to heat loss?
conduction, convection, radiation
