Chirped-pulse Amplification
Chirped-pulse Amplification - Related Videos
02:42
Formal Charges
0 Views •
2020
In some cases, there are seemingly more than one valid Lewis structures for molecules and polyatomic ions. The concept of formal charges can be used to help predict the most appropriate Lewis structure when more than one reasonable structure exists. Calculating Formal Charge The formal charge of an atom in a molecule is the hypothetical charge the atom would have if the electrons in the bonds are evenly distributed between the atoms. Alternatively, formal charge results when from the number...
09:44
Rapid Amplification of cDNA Ends
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2023
Source: Pablo Sanchez Bosch2, Sean Corcoran2 and Katja Brückner1,2,3 1Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research 2Department of Cell and Tissue Biology, 3Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA Rapid Amplification of cDNA Ends (RACE) is a technique that allows amplification of full-length cDNA from mRNA by extending to the 3’ or 5’ end, even without prior knowledge of the sequence (Frohman et al.,...
03:27
Ions and Ionic Charges
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2020
In ordinary chemical reactions, the nucleus — which contains the protons and neutrons of each atom and thus identifies the element — remains unchanged. Electrons, however, can be added to atoms by transfer from other atoms, lost by transfer to other atoms, or shared with other atoms. The transfer and sharing of electrons among atoms govern the chemistry of the elements. During the formation of some compounds, atoms gain or lose electrons to form electrically charged particles called ions. When...
02:41
Amplification of a Suicide Plasmid in a Bacterial Host
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2025
Source: Tomás, J. M., et al. Generation of Null Mutants to Elucidate the Role of Bacterial Glycosyltransferases in Bacterial Motility. J. Vis. Exp. (2022).This video demonstrates the initiator-dependent amplification of a suicide plasmid in E. coli. The plasmid, which carries an antibiotic resistance gene, replicates only in the presence of an initiator protein encoded by the host. After electroporation and incubation in recovery medium, the mixture is plated on antibiotic-containing agar.
11:20
Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
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Cited by 2 •
2012
An experimental method to examine the early plasma evolution induced by ultrashort laser pulses is described. Using this method, high quality images of early plasma are obtained with high temporal and spatial resolutions. A novel integrated atomistic model is used to simulate and explain the mechanisms of early plasma.
FAQs
Temporal stretching lowers a pulse’s peak power before it reaches the amplifier. Because amplification occurs while the pulse remains relatively low power, optical components experience less damaging intensity than they would during direct amplification of a compressed pulse. This enables later recompression to a short, intense pulse without exposing the amplifier to the full peak power.
Dispersive optics, including diffraction gratings, reverse the temporal spreading introduced during pulse stretching. They bring the different parts of the amplified pulse back into a brief time interval, restoring short duration and producing a much higher peak intensity. Their function is therefore central to converting a safely amplified pulse into one suitable for ultrafast biological applications.
High peak intensity allows substantial energy to be delivered within an extremely short interval, while the CPA sequence limits the risk of damaging the laser system itself. In bioengineering, this concentrated delivery supports confined energy deposition. The resulting spatial selectivity can improve precision during microsurgery and laser-based processing of biological materials.
The key characteristics are pulse duration, peak power, and the ability to control when high intensity occurs. Stretching and recompression separate amplification from the final intense-pulse interaction, while the brief recompressed duration supports localized energy delivery. Together, these features make the technique relevant when biological work requires strong optical effects with limited spatial spread.
A typical sequence begins by stretching the incoming pulse, followed by amplification while its peak power is reduced. Dispersive optics then recompress the amplified pulse to a brief duration. For bioengineering experiments, this sequence provides the intense ultrashort output needed for multiphoton microscopy, precision microsurgery, or processing biological materials.
In multiphoton microscopy, the intense ultrashort output supports imaging approaches that depend on concentrated optical energy. During precision microsurgery, confined deposition can improve spatial selectivity and help reduce collateral damage. These applications use the same controllable ultrafast behavior for different goals: resolving biological structures in imaging and modifying tissue or biological material with greater precision.
The very brief pulses provide a way to interrogate biological events on rapid timescales. By delivering controlled ultrafast light, researchers can examine fast biological dynamics and investigate how biological systems respond to tightly timed energy deposition. This capability also contributes to developing advanced imaging and therapeutic tools in bioengineering.