Infrared Laser Excitation
Infrared Laser Excitation - Related Videos
09:38
Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
0 Views •
Cited by 4 •
2015
We describe the generation of far-infrared radiation using an optically pumped molecular laser along with the measurement of their frequencies with heterodyne techniques. The experimental system and techniques are demonstrated using difluoromethane (CH2F2) as the laser medium whose results include three new laser emissions and eight measured laser frequencies.
12:00
Synthesis of Gold Nanoparticle Integrated Photo-responsive Liposomes and Measurement of Their Microbubble Cavitation upon Pulse Laser Excitation
0 Views •
Cited by 2 •
2016
This protocol describes a simple preparation method for gold nanoparticle integrated photo-responsive liposomes with the commercially available materials. It also shows how to measure the microbubble cavitation process of the synthesized liposomes upon the treatment of pulsed laser.
11:04
Control of Cell Geometry through Infrared Laser Assisted Micropatterning
0 Views •
2021
The protocol presented here enables automated fabrication of micropatterns that standardizes cell shape to study cytoskeletal structures within mammalian cells. This user-friendly technique can be set up with commercially available imaging systems and does not require specialized equipment inaccessible to standard cell biology laboratories.
08:11
Infrared Spectroscopy
0 Views •
2023
Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA This experiment will demonstrate the use of infrared (IR) spectroscopy (also known as vibrational spectroscopy) to elucidate the identity of an unknown compound by identifying the functional group(s) present. IR spectra will be obtained on an IR spectrometer using the attenuated total reflection (ATR) sampling technique with a neat sample of the unknown.
10:12
Near-infrared Fluorescence Imaging of Abdominal Aortic Aneurysms
0 Views •
2023
Source: Arvin H. Soepriatna1, Kelsey A. Bullens2, and Craig J. Goergen1 1 Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 2 Department of Biochemistry, Purdue University, West Lafayette, Indiana Near-infrared fluorescence (NIRF) imaging is an exciting optical technique that utilizes fluorescent probes to visualize complex biomolecular assemblies in tissues. NIRF imaging has many advantages over conventional imaging methods for noninvasive imaging of diseases.
FAQs
Tight focusing concentrates the infrared photons at a defined focal point, where the fluorophore can undergo two-photon excitation. Fluorescence therefore arises mainly within that focal region rather than throughout the illuminated path. This spatial restriction creates optical sectioning, allowing researchers to distinguish signals from selected planes and reduce unwanted excitation in surrounding brain tissue.
Pulsed operation provides brief periods in which two lower-energy infrared photons can be absorbed nearly simultaneously by a fluorescent molecule. The required interaction becomes concentrated at the laser focus, where photon density is highest. In neuroscience experiments, this enables localized fluorescence from indicators, proteins, or structures while limiting excitation outside the selected imaging plane.
Restricting excitation to the focal region reduces fluorescence and photodamage outside the plane being examined. This improves spatial specificity because signals from nearby regions are less likely to contribute to the measurement. The same limitation of off-plane excitation also supports imaging in living brain tissue, where preserving surrounding tissue is important for observing neural activity and circuitry.
The approach can be applied to calcium indicators, fluorescent proteins, and fluorescently labeled neuronal structures. Calcium indicators support measurements associated with neural activity, whereas fluorescent proteins and labeled structures help visualize cells or circuitry. Because excitation can be confined to a selected focal plane, these targets can be examined with greater spatial specificity in living brain tissue.
Infrared laser excitation supports optical measurements in regions beneath the tissue surface by generating fluorescence at a tightly selected focal point. Its optical sectioning limits excitation outside that plane, which helps preserve spatial specificity during imaging. This makes the method useful for examining living brain tissue at depth rather than restricting observations to superficial structures.
By exciting fluorescent calcium indicators, proteins, or neuronal structures within selected focal regions, the method provides localized optical signals from living brain tissue. Researchers can use those signals to monitor neural activity and examine the organization of circuitry. Reduced out-of-focus excitation and lower surrounding photodamage improve the specificity of these measurements, particularly when imaging beneath the surface.