Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Light Materials Interaction

In course

MICRO-520: Laser microprocessing

The physical principles of laser light materials interactions are introduced with a large number of industrial application examples. Materials processing lasers are developing further and further, the lecture presents the physical limitations of the proces ...

Description

This lecture covers the interaction between light and materials, discussing properties of light such as photons, waves, and collective properties. It also explores topics like absorption mechanisms, spectroscopy, and the properties of dielectrics and metals.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Instructor

Patrik Willi Hoffmann

Official source

Ontological neighbourhood

Chemistry

Physical chemistry: Spectroscopy

Related concepts (32)

Attenuation coefficient

The linear attenuation coefficient, attenuation coefficient, or narrow-beam attenuation coefficient characterizes how easily a volume of material can be penetrated by a beam of light, sound, particles, or other energy or matter. A coefficient value that is large represents a beam becoming 'attenuated' as it passes through a given medium, while a small value represents that the medium had little effect on loss. The SI unit of attenuation coefficient is the reciprocal metre (m−1).

Molar absorption coefficient

In chemistry, the molar absorption coefficient or molar attenuation coefficient (ε) is a measurement of how strongly a chemical species absorbs, and thereby attenuates, light at a given wavelength. It is an intrinsic property of the species. The SI unit of molar absorption coefficient is the square metre per mole (), but in practice, quantities are usually expressed in terms of M−1⋅cm−1 or L⋅mol−1⋅cm−1 (the latter two units are both equal to ). In older literature, the cm2/mol is sometimes used; 1 M−1⋅cm−1 equals 1000 cm2/mol.

Absorption spectroscopy

Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of electromagnetic radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons, from the radiating field. The intensity of the absorption varies as a function of frequency, and this variation is the absorption spectrum. Absorption spectroscopy is performed across the electromagnetic spectrum.

Infrared spectroscopy

Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functional groups in solid, liquid, or gaseous forms. It can be used to characterize new materials or identify and verify known and unknown samples. The method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer (or spectrophotometer) which produces an infrared spectrum.

Refractive index

In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or refracted, when entering a material. This is described by Snell's law of refraction, n1 sin θ1 = n2 sin θ2, where θ1 and θ2 are the angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices n1 and n2.

Related lectures (31)

Basic concepts of photons and x-rays

Explores the interaction of x-rays with matter, matching photon energy, and ionizing radiation.

Light Propagation and Absorption

Explores light propagation, absorption, and color phenomena in different media, including conductors, semiconductors, and metals.

Molecular Spectroscopy: Absorption and Emission

Explores molecular spectroscopy, focusing on absorption and emission of radiation, molecular structure determination, and vibrational spectroscopy.

Light Dosimetry in Tissues

Explores light dosimetry in tissues for photomedicine applications, covering mechanisms of light therapy, laser classification, and the influence of laser parameters on treatment outcomes.

Molecular Vibrations and Electronic Transitions: Insights