Big lasers for big
science
Made by Novikov Artem CM9-41
10. 03. 2022
Contents
1.Purposes of science lasers
2.Spectroscopy
3.Measuring the distance to the Moon
4.Atmospheric remote sensing
5.Photochemistry
6.Laser magnetization
7.Thermonuclear fusion
Purposes of science lasers
Today scientists, lab technicians, engineers, and
industrial technicians regularly utilize lasers to perform a wide range of important tasks. They measure distances, both short and long, with lasers, giving astronomers, geographers, and surveyors much more accurate figures than were available before the invention of these devices.
They also use lasers to study microscopic objects, including molecules.
Spectroscopy
With the help of frequency tuning, spectroscopic studies of various nonlinear optical effects are
carried out, and the control of the polarization of laser radiation allows for coherent control of the processes under study.
Measuring the distance to the Moon
During the flights to the Moon by manned and unmanned vehicles, several special reflectors were delivered to its surface. A specially focused laser beam was sent from Earth and the time it
takes to travel to the lunar surface and back was measured. Based on the value of the speed of
light, the distance to the moon was calculated.
Atmospheric remote sensing
The use of adaptive optics methods in ground-based telescopes can significantly improve the image quality of astronomical objects by measuring and compensating for
optical distortions of the atmosphere. The laser
radiation is scattered in the upper layers of the
atmosphere, creating a reference light source
visible from the earth's surface – an artificial
"star". The light from it, which passed through
the atmospheric layer on the way back to earth, contains information about optical distortions
taking place at a given time. The atmospheric
Photochemistry
Some types of lasers can produce ultrashort light pulses measured in femtoseconds. Such pulses
can be used to trigger and analyze chemical
reactions. Ultrashort pulses can be used to study chemical reactions with high time resolution,
allowing reliable isolation of short-lived compounds. Manipulation of the polarization of
the pulse allows you to selectively choose the
direction of a chemical reaction from several
possible ones (coherent control).
Laser magnetization
Ultrashort laser pulses are used for ultrafast
control of the magnetic state of the material,
which is currently the subject of intensive research. Many opto-magnetic phenomena have
already been discovered, such as ultrafast demagnetization in 200 femtoseconds, thermal
remagnetization by light and non-thermal optical magnetization control via light polarization.
Laser tweezers
Optical tweezers are a device that allows manipulating microscopic objects using laser
light. It allows applying forces from femtonewtons to nanonewtons to dielectric
objects and measuring distances from several
nanometers. In recent years, optical tweezers
have been used to study the structure and working principle of proteins. Laser technologies have been widely used in science
and will only develop in the future. New devices using laser radiation will be created, for example, there are already laser microscopes that give a
higher resolution compared to optical microscopes that use white light.
Thermonuclear fusion
One of the ways to solve the problem of retaining heated plasma in a nuclear reactor
may be to use lasers. At the same time, a small
volume of fuel is irradiated with powerful laser
radiation from all sides for a small period of time. As a result of irradiation, the target surface
evaporates, exerting enormous pressure on the
inner layers. This pressure compresses the target to ultra-high densities. Thermonuclear reactions
can occur in a compressed target when a certain
temperature is reached. Heating is possible both directly by pressure forces and with the use of an additional heavy-