L1-D

Applications of Lasers with Beam Expanders
1. In Laser Rangefinder - When long range is to be measured, it is imperative to reduce the beam divergence, so that enough energy will be reflected from the target to the detector.
2. In applications where the smallest possible spot size is needed, First the beam is expanded, and than it is focused at the desired spot.
3. In applications that need long range transport of the laser beam:
1. Laser Weapons.
2. Energy transportation using laser beams

Beam reduction based on Galileo’s Telescope
When the diameter of the beam need to be reduced, an inverse telescope can be used. It is the same Galileo’s telescope, but the laser beam enters


Choosing Basic Transverse Mode Using Pinhole
The diameter of the basic transverse mode TEM00 is the smallest of all possible laser modes inside the cavity. Each of the higher modes has a bigger diameter, Thus by limiting the aperture inside the cavity higher modes can be eliminated. Choosing the pinhole diameter equal to the diameter of the basic laser transverse mode will cause losses to higher modes, and free transmission of the basic mode.