EXP-07 Generation of Short Pulses

Topics

Rate Equation Model
Steady State Solutions
Time Dependent Solutions
Spiking
Saturable Absorber
Nd:YAG Laser
Q - Switch


Examples of Investigations and Measurments

Mechanical chopper
By means of the mechanical light chopper, the €žinitial spike€ś can be demonstrated. One can observe that the initial spike is not yet a pure giant pulse but the tendency of the system to store energy becomes obvious. With the internal modulator of the diodelaser controller, further spiking effects can be shown. In this case, the rise time is shorter than for the chopper.

Saturable absorber
After optimising the output power of the Nd:YAG laser module L (Cr:YAG - crystal) is inserted into the resonator. After adjustment one observes a train of needle-like pulses on the oscilloscope. Groups of amplitudes of different height show that there are also transversal modes as the result of Q-switching. The repetition rate depends essentially on the losses and on the pump power. Its upper limit is limited by the lifetime of the initial level.

Additional experiments
This set-up uses for the generation of the fundamental radiation the same Nd:YAG laser as within the EXP-08. Therefore all therein described measurements can be performed as well
 
 


Required Equipment

Cat. No.     Qty.   Description
02.0500      1        Profile rail, 500 mm
02.2126      3        Mounting plate, click 25, carrier 20
02.2202      1        Filter plate holder for 3 filters, carrier 30
02.2526      1        Target screen, click 25
02.5404      1        Laser mirror adjustment holder, right LSF
02.5406      1        Laser mirror adjustment holder, left LSF
04.0030      1        Focusing optic, triplet, f=6, NA 0.6, click 25
04.0050      1        Biconvex lens f=60, 18, click 25
04.0122      1        Coloured glass filter, RG-1000
04.0302      1        Infrared display card 0.8-1.2 µm
04.0306      1        Optic cleaning set
04.0486      1        Nd:YAG rod, LSF 650 1/2€ť
04.0490      1        Laser mirror, NIR 100
05.0210      1        DIMO 808, 450 mW, Peltier cooler, XY adjustment holder
07.0003      1        BNC connection lead, 1.5 m, set of 3
07.0102      1        Photodetector, Si PIN, in housing
07.0200      1        Laserdiode controller LDC-01
07.0226      1        Light-chopper controller LCC-01
09.0074      1        Passive q-switch
09.0076      1        Light chopper, carrier 60
10.0070      1        EXP 07 manual
Required Options:
09.0140      1        Dual trace oscilloscope 100 MHz
Options:           
07.0230      1        Linear triangle function generator FG-01
09.0077      1        Active q-switch, Pockels€™s cell, HV driver
09.0086      1        Spatial filter, adjustable iris diaphragm, click 25