Title: Investigating with Lasers
Date: February 10, 2010
Group3:
Gabrielle-Glossary
Ben- Polarization Puzzle
Adam- Boltzmann Calculations and Slide 11
Jasmine- Excimer and Chemical Lasers and Groove Line Separation Measurement
Glossary: 1. LASER- Light amplification by stimulated emission of radiation
2. Amplification- the building up and concentration of a large number of identical photons
3. Stimulated Emission- Process where one photon causes the emission of another photon with identical properties
4. Population Inversion- this is where the state of higher energy is “populated” with more molecules than the state of lower energy
5. Lifetime- Average time it takes for one state to change to another state. This occurs when the molecules de-excite and gives off a photon in the process of transformation
6. Absorption- takes an atom or molecule from a lower to a higher state. Absorption is the inverse of Stimulated Emission.
7. Spontaneous Emission- process where an excited atom or molecule changes from its excited state to a lower state and emits a photon in the process.
8. LASing (threshold)- minimum power needed to begin the laser
9. 3 State System- the laser transition takes place between an excited (lasing state, longer τ) and ground state. This is not an efficient state system.
10. 4 State System- the laser transition takes place between two excited states (lasing state, longer τ and shorter τ). This is the more efficient state system
11. Laser Pumping- process of supplying energy required for the amplification
12. Monochromaticity- the wavelength of the photons are almost the same
13. Intensity- the brightness of the laser
14. Collimation- where the laser beam doesn’t spread out rapidly
15. Coherence- collection of photons
16. Excimer Laser- a powerful laser that is usually operated in the Ultraviolet region. The laser gets its power by amplifying the power of light using a gain medium, a mixture of a noble gas and halogen to generating nanosecond pulses. When in the presence of a high voltage electric discharge, the pulses create excimers, dimers that will only bond in their excited state. After spontaneous emission the excimer dissociates and no reabsorption of the radiation generated occurs.
17. Chemical Laser- a continuous or pulse laser that uses the chemical reaction between emitted atoms for excitation and population inversion to create a beam.
Polarization Puzzle
A laser beam contains rays in all directions and polarizers only allow rays of a certain direction through.
The 3rd lens polarized light in a different direction.
Slide 11 answer
There must be a sufficient number of ground state atoms present to absorb a photon to produce an excited atom (molecules). The atoms can then de-excite and emit a photon to continue the cycle.
Date: February 10, 2010
Group3:
Gabrielle-Glossary
Ben- Polarization Puzzle
Adam- Boltzmann Calculations and Slide 11
Jasmine- Excimer and Chemical Lasers and Groove Line Separation Measurement
Glossary:
1. LASER- Light amplification by stimulated emission of radiation
2. Amplification- the building up and concentration of a large number of identical photons
3. Stimulated Emission- Process where one photon causes the emission of another photon with identical properties
4. Population Inversion- this is where the state of higher energy is “populated” with more molecules than the state of lower energy
5. Lifetime- Average time it takes for one state to change to another state. This occurs when the molecules de-excite and gives off a photon in the process of transformation
6. Absorption- takes an atom or molecule from a lower to a higher state. Absorption is the inverse of Stimulated Emission.
7. Spontaneous Emission- process where an excited atom or molecule changes from its excited state to a lower state and emits a photon in the process.
8. LASing (threshold)- minimum power needed to begin the laser
9. 3 State System- the laser transition takes place between an excited (lasing state, longer τ) and ground state. This is not an efficient state system.
10. 4 State System- the laser transition takes place between two excited states (lasing state, longer τ and shorter τ). This is the more efficient state system
11. Laser Pumping- process of supplying energy required for the amplification
12. Monochromaticity- the wavelength of the photons are almost the same
13. Intensity- the brightness of the laser
14. Collimation- where the laser beam doesn’t spread out rapidly
15. Coherence- collection of photons
16. Excimer Laser- a powerful laser that is usually operated in the Ultraviolet region. The laser gets its power by amplifying the power of light using a gain medium, a mixture of a noble gas and halogen to generating nanosecond pulses. When in the presence of a high voltage electric discharge, the pulses create excimers, dimers that will only bond in their excited state. After spontaneous emission the excimer dissociates and no reabsorption of the radiation generated occurs.
17. Chemical Laser- a continuous or pulse laser that uses the chemical reaction between emitted atoms for excitation and population inversion to create a beam.
Polarization Puzzle
Slide 11 answer
There must be a sufficient number of ground state atoms present to absorb a photon to produce an excited atom (molecules). The atoms can then de-excite and emit a photon to continue the cycle.
Boltzmann Calculations
Measurement and Calculations of Groove/Line Distance
Laser Study Questions