Photon Excitation Energy
Photon Excitation Energy - Related Videos
04:32
Two-Photon In Vivo Imaging of the Mouse Retina
0 Views •
2025
Source: Wang, Z., et al. Transpupillary Two-Photon In Vivo Imaging of the Mouse Retina. J. Vis. Exp. (2021).This video demonstrates a technique for in vivo retinal imaging using two-photon microscopy. Anesthetized mice are prepared for imaging by securing their heads, Applying eye lubricant, and placing a coverslip over the eye. Retinal ganglion cells (RGCs) expressing fluorescent proteins are first visualized using epifluorescence for alignment. Finally, two-photon imaging is employed,...
01:35
Light as Energy
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2019
The energy required to carry out photosynthesis is light— typically electromagnetic radiation from the sun. The range of all possible wavelengths is known as the electromagnetic spectrum. Photons A photon is a discrete electromagnetic particle or bundle of energy. Photons are characterized by their frequency, wavelength, and amplitude, similar to the properties of a wave. Waves with higher frequencies transmit more energy and have shorter wavelengths than longer wavelengths that transmit less...
02:58
Two-Photon Microscopy for In Vivo Imaging of Mouse Brain Microvasculature
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2025
Source: Nishimura, C. et al. Quantification of Cerebral Vascular Architecture using Two-photon Microscopy in a Mouse Model of HIV-induced Neuroinflammation. J. Vis. Exp. (2016). This video demonstrates the in vivo visualization of cortical capillaries in the mouse brain using two-photon microscopy. It outlines the steps for injecting a fluorescent dye into an anesthetized mouse with a thin-skull cortical window, preparing the setup for imaging, and acquiring detailed images of brain...
13:02
Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation
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Cited by 3 •
2017
We present a protocol for fabricating 1-D photonic crystal cavities on subwavelength diameter silica fibers (optical nanofibers) using femtosecond laser-induced ablation.
03:18
Two-Photon Microscopy for Monitoring Calcium Dynamics in Mouse Retinal Cone Photoreceptors
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2025
Source: Kulkarni, M. et al. Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina. J. Vis. Exp. (2015)This video demonstrates the use of two-photon microscopy to monitor calcium dynamics in cone photoreceptors of a transgenic mouse retina. It outlines the steps for preparing retinal slices, imaging FRET-based calcium biosensors, and analyzing fluorescence changes to quantify calcium levels under background illumination and light stimulation.
FAQs
Frequency and wavelength set the photon energy through E = hν = hc/λ. Increasing frequency or decreasing wavelength produces a higher-energy photon, while decreasing frequency or increasing wavelength produces a lower-energy photon. Absorption occurs when this value matches an allowed transition or the relevant material energy gap, making spectral selection central to engineered light-based systems.
In a semiconductor, photon excitation energy must correspond to the material’s energy gap for the intended absorption process. This relationship connects the selected light spectrum with device behavior in photodetectors, photovoltaic cells, and light-emitting devices. Engineering the match helps determine which photons interact effectively with the material and supports controlled conversion between light and other forms of energy.
The absorbed energy can produce different kinds of excited states, including electronic or vibrational states. The relevant allowed transition determines which state is reached when the photon is absorbed. This distinction matters because spectroscopy systems can use these state changes to characterize materials, while engineered devices may instead emphasize controlled electronic excitation, absorption, or emission.
An energy value alone does not guarantee absorption. The photon must also match an allowed transition within the atom, molecule, semiconductor, or other material. This condition explains why changing the light frequency can alter the observed response and why engineered optical systems require careful control of the incident spectrum when designing absorption or emission behavior.
A spectroscopy system can examine how a material responds to photons with selected energies, using absorption or related changes in excited states as characterization information. Comparing the response across frequencies or wavelengths helps identify energy relationships within the material. This approach supports precise material analysis and links measured optical behavior to electronic, vibrational, or other transitions.
These devices rely on controlled interactions between light and material energy states, but their engineering goals differ. Photodetectors and photovoltaic cells depend on useful light absorption, whereas lasers and light-emitting devices depend on controlled emission. Selecting photon energies that suit the material transitions or energy gap helps connect optical input or output with the intended device performance.