Laser Focused and Then Some

When most people hear the word “laser”, they think of sci-fi thrillers such as Star Wars, with its hand- held laser blasters, but Albert Einstein proposed the idea of a laser over 100 years ago. Einstein based his theory of stimulated light emission on fundamental physics, more specifically quantum theory. Having recently shown that light was derived of packets of energy (photons), Einstein postulated that if the atoms making up the material are provided with excess energy, individual excited atoms emitting photons could stimulate other excited atoms nearby to do the same. As a result, all photons will have equal energy and move off in the same direction. While the theory was sound, it would take decades before suitable technology was available that would allow the idea to be put into practice. Ultimately, it was shown that when a material is pumped with energy in a mirrored cavity, photons bounce back and forth amplifying the emission of photons. The photons were then allowed to escape through a transparent section in the mirrored surface as a laser beam. Charles Townes at Columbia University produced the first device proving the theory in 1953. The device was capable of amplifying microwaves and was coined the maser.

Tatoute. 2006. Wikipedia.

In 1960, Theodore Maiman, at the Hughes Research Labs in California, produced the first visible-light laser with ruby as the laser medium. However, at this time the laser had few applications, as did many discoveries stemming from basic research. This was to change toward the end of the 20th century, as laser research saw a large expansion and development of high-powered gas, chemical and semiconductor-based lasers. It was not until the development of a laser that worked at room temperature with little or no cooling, that the first widespread use outside of research was realized, in the form of the compact disk (CD). Today most lasers are of the semiconductor diode type and found throughout industry as well as consumer products of all types. Many lasers have been adapted for biological and biomedical applications ranging from basic research to medical procedures.

Demonstration of a Helium-Neon laser at the Kastler-Brossel Laboratory in Paris. Monniaux, D. 2004. Wikipedia.

Over the past several years, BioTek has implemented lasers in several instruments. The first was a 680 nm semiconductor laser incorporated into the Synergy Neo for use with PerkinElmer AlphaScreen® technology. BioTek then incorporated a red semiconductor laser as a rapid focusing method during image acquisition for our Cytation™ and Lionheart™ product lines. Most recently, a nitrogen laser operating a 337 nm is an option for the Synergy™ Neo2 Hybrid Multi-Mode Reader
for peak TR-FRET performance. The laser produces approximately 6x more energy than a xenon flash lamp at that wavelength and can flash approximately 2x faster. This results in ideal performance for high throughput screening where both sensitivity and high sample throughput are required. Typical assays include GPCR, kinase, biomarker and cytokine assays using technologies such as Cisbio HTRF®, LanthaScreen™, DELFIA® and LANCE®.