Home work Physical and Theoretical Chemistry IV

- Molecular Spectroscopy -

Discussion  Fr 10.12.2004 at 10:30,  PK11-2



 

Home work 6            Laser systems and molecular rotation
 

 

Exercise 1:       

a) What is the advantage of a dye or a Ti:Sa laser compared to a Ruby or Nd:Yag laser?

b) Why can you create laser pulse length of a few femto seconds using a Ti:Sa laser, while the shortest pulse length of a Nd:Yag laser is in the order of 100 ps?

c) The Ti:Sa  can operate as a laser in the range of 700-900nm. How many logitudinal modes are in this range for a resonator of 2 meter length?

 

Exercise 2:    Laser specifications

a) The output power of a Nd:Yag laser is 100 Watt (continuous wave). Now the laser is q-switched and operates at a repetition rate of 30 Hz. The average power is 30 Watt: What is the pulse energy (Joule per laser pulse)? What is the pulse power, if the pulse length is 5 ns?

b) What can be the narrowest linewidth of the Nd:Yag laser beam, if the pulse width is 5 ns?.

c) A continuous dye laser beam (spectral bandwidth 1 MHz)  at 500 nm is amplified by the pulse of a Nd:Yag laser (pulse width 5 ns). What is the bandwidth of the amplified dye laser beam?

 

Exercise 3:   rotational constants

Calculate the rotational constants for CO and CO2 using the bond lengths in the literature.