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-