The new system is designed to support all of the research needs of the U.F. Health Cancer Center The system is based on a proven technology platform with a proven track record in research-grade laser systems that can be used to perform a wide range of biological, chemical, and physical studies.
U.F. Health’s new Laser Microbeam and Manipulation System (LAMMPS) is located on the second floor of the new U.F. Health Cancer Research Building, which is currently under construction at the corner of University Boulevard and Southwest 21st Street. “The new laser system will be a powerful tool for studying cosmo laser equipment the effects of radiation and other stressors on living cells, tissues, and organisms,” says James S. H. Wang, Ph.D. professor of pharmacology in the U.F. College of Medicine.
History of Laser
In 1916, Albert Einstein suggested that atoms release excess energy as light when stimulated by light. This led to the invention of the laser. Rudolf Walther Ladenburg observed it stimulated emission for the first time in 1928, but it was thought to have no practical application at the time.
Charles H. Townes, then at Columbia University in New York City, developed a way to produce stimulated emission at microwave frequencies in 1951. He demonstrated a working device at the end of 1953 that focused “excited” (see Energy levels and stimulated emissions) ammonia molecules into a resonant microwave cavity, where they emitted pure microwaves. Towns called it a maser for “microwave amplification by stimulated emission of radiation.” Aleksandr Mikhaylovich Prokhorov and Nikolay Gennadiyevich Basov of the P.N. I. Lebedev Physical Institute in Moscow independently developed the theory of maser operation. The Nobel Prize in Physics was awarded to all three men in 1964 for their work.
Fundamental principles
Energy Levels and Stimulated Emissions
A laser’s emission is determined by the rules of quantum mechanics, limiting atoms and molecules to storing discrete amounts of energy that depend on the atom or molecule’s nature. Particles have their lowest energy levels when their electrons are arranged in the closest possible orbits to their nucleus (see electronic configuration). Ground states are the lowest energies. As electrons move from higher energy levels to lower energy levels, they emit the extra energy they have absorbed as light. Excited states are not stable; electrons move from higher-energy levels to lower-energy levels as they drop from higher to lower levels.
When an electron drops to a lower energy level, it emits some of its excess energy as light. The wavelength of the emitted light is determined by the energy difference between the excited state and the ground state of the atom or molecule. The energy released by the transition of an electron from one energy level to another may be measured by the frequency of the emitted light, which is determined by the energy difference between the two levels. Lasers produce light in narrow frequency ranges.
The emitted light is usually a single wavelength, and the width of the emission spectrum depends on the type of laser and the particular atom or molecule being excited. A laser’s frequency may be changed by changing either the frequency of the laser beam or the frequency of the atoms or molecules that are absorbing the beam. In addition to being able to change the frequency of the laser beam, it is often desirable to change the frequency of the laser beam as it strikes an object.
Laser elements
It is possible to produce population inversions with gases, liquids, or solids, but most laser media are gases or solids. Laser gases are typically contained in cylindrical tubes and excited by an electric current or external light source, which is known as pumping the laser. A solid-state laser can also use semiconductors or transparent crystals that contain small amounts of light-emitting atoms.
Solid-state lasers can be made very small and have a large power output because of their large cross sections. Semiconductor lasers usually have a very small cross-section. Solid-state lasers are typically divided into diode lasers and fiber lasers. Diode lasers are small devices that can be used in many applications. Fiber lasers consist of multiple layers of glass that are fused. Fiber lasers are very efficient, but they are much more expensive than diode lasers.