answers
Briefly describe second-harmonic generation. Ans✓✓✓ Light passing
through certain nonlinear crystals leads to the generation of a
nonlinear polarization wave at twice the frequency and so light at twice
the frequency can be produced
Describe excimer lasers. Ans✓✓✓ Contain mixture of He, F and noble
gas ; noble gas is excited and reacts with F to form excimers that decay
and give off radiation
Describe how light passes through a medium if no extraneous
processes occur. Ans✓✓✓ The oscillating EM fields lead to polarization
of the electron clouds which then relax and re-emit the radiation with
no permanent energy change
For what spectroscopy method are sample containers not needed?
Ans✓✓✓ Emission
How are effective bandwidth and transmission related? Ans✓✓✓ They
are directly proportional
How are interference filters constructed? Ans✓✓✓ Dielectric layer of
some thickness sandwiched between thin metal film and glass plates
, How can a narrow band of spectrum be isolated with absorption filters?
Ans✓✓✓ Using two cutoff filters
How can dye lasers be tuned? Ans✓✓✓ Changing the dye molecule?
How can the effects of stray radiation be mitigated? Ans✓✓✓ Using a
wavelength selector to filter out extraneous wavelengths
How do absorption filters work? Ans✓✓✓ They absorb some portion
of the spectrum, cutoff filters are a subset that have 100%T for some
region and 0%T otherwise
How do Barrier-Layer Photovoltaic Cells work? Ans✓✓✓ Radiation
strikes a semiconductor layer which frees an electron, the electron
moves through the wire to recombine with the hole and register a
current proportional to the number of photons that strike
How do holographic filters work? Ans✓✓✓ Modulating laser
wavelength and incident angle results in a grid pattern that can screen
out certain wavelengths
How do interference filters work? Ans✓✓✓ Beams that strike them are
bounced between the two metal layers in the dielectric and
interference results in only one set wavelength interfering
constructively and leaving the filter