Table of Contents
Lasers in Chemistry
Requirements for a laser
Gain can only be achieved with population inversion
A two level system cannot give rise to a population inversion
Analysis of a two level system using differential equations
A two level system can give rise to equal population of ground and excited states
A three level system: the minimum requirement for a laser
A three level system provides a route to a population inversion
Analysis of a three level system
Simple solution of a three level system uses steady state approximation
The addition of a third state allows for creation of a population inversion
Four level system produces superior results for laser design
d-d transitions can give a useful four level system for tunable lasers
Comparison of three and four state systems
Cr(III) ligand field is nearly Oh so help is required from other metals
Cavity modes
Longitudinal modes
Longitudinal modes
Transverse modes
TEM00 is a transverse mode with no nodes
TEM10 and TEM 01 are transverse modes with one node
TEM11 is a transverse mode with two nodes
Scientific Lasers
Creation of a population inversion by electrical discharge
HeNe Laser
HeNe laser cavity
Ar and Kr ion lasers
Ar and Kr ion lasers
Ar and Kr ion lasers
Nd:YAG lasers
Nd:YAG lasers
Nd:YAG lasers
Nd:YAG lasers
Nd:YAG lasers
Nd:YAG lasers
CO2 lasers
CO2 lasers are infrared lasers
The gain curve of CO2 spans the rotational state energies of the molecule
Excimer lasers
Dye lasers
Laser safety
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