Malus Law Verification
Pockels and Kerr effect investigation
1. Theoretical description
1.1. Malus Law
1.2 Pockels and Kerr effects
2. Set of instruments:
- optical bench - polarizer - analyzer - mikroammeter - voltage power supply - Pockels cell and Kerr cell - He-Ne laser
- gauge type “Metex”
- photocell
3. Course of the exercise
A schematic diagram of the measurement arrangement for Malus law verification and electrooptical effects study is shown in Fig. 1 and Fig.2 respectively. The system consists of the light source (a laser diode), power supply, polarizer, Pockels cell (Kerr cell), analyser, a photocell, high-voltage supply and an ammeter.
4. Measurements
a) Verification of Malus law
Connect set-up according to Fig.1
Fig.1. Schematic diagram for the Malus law verification
1. Turn on power supply of the laser and ammeter
2. Justify the setup so way the light passing through all setup elements could enter to the fotoelement.
3. Arrange polarizer and analyzer on ZERO
4. Do the measurements transmission as a analyzer angle function (angle range 0º- 360º, with step 10º)
Results study
5. Make plot of transmission set-up as a defluxion angle function ( )
min max
min f α
I I
I
I =
−
− ;
where Imax and Imin are the maximum and minimum value of the intensity respectively
6. This results compare with the cos2α function
Fotoelement
Power supply
Laser diode
Polarizer Analyzer
µµµµA
b) Pockels (Kerr) effect investigation
Connect set-up according to Fig.2
Fig.2. Schematic diagram for the Pockels (Kerr) effect
1. Turn on voltage power supply of the laser and ammeter
2. Justify the setup so way the light passing through all setup elements could enter to the fotoelement.
3. Arrange polarizer on ZERO
4. Turn analyser to find maximum of the intensity 5. Turn analyser on 90º
6. Between the analyser and polarizer put the Pockels (Kerr) cell 7. Connect Pockels (Kerr) cell with voltage power supply
8. Turn polarizer on 45º respect of electric field in Pockels (Kerr) cell
9. Do the measurements for voltage range from -1000 to 1000 V, with step 25 V
Results study
10. Do the measurements transmission as a voltage function put to the Pockels (Kerr) cell I=f(U)
11. Using transmission date calculate voltage half-wave value
12. Make plot of voltage dependence of the phase shift between the fast and slow light wave in crystal (clues give lecturer) ∆Γ= f(U)
Fotoelement
Power supply
Laser diode
Polarizer
Pockels (Kerr)
cell Analyzer
µµµµA
