In many fields such as materials science, geological exploration, environmental monitoring, cultural relic protection, metallurgical industry, and even planetary exploration, rapid, accurate, and in-situ identification of material element composition is a fundamental and critical requirement. Although traditional chemical analysis methods have high accuracy, they often require complex pre-processing, sample destruction, and are time-consuming. The emergence of laser-induced breakdown spectroscopy technology has changed this situation. The laser-induced spectrometer based on LIBS principle has unique advantages such as no need for sample preparation, multi-element simultaneous analysis, minimal or even near non-destructive testing, and remote/online detection. This article will systematically introduce its working principle, technical characteristics, typical applications, and future development directions.

1、 Working principle: Igniting atomic fingerprint light with laser

The core principle of laser-induced spectrometer is extremely ingenious:

Firstly, a high-energy pulsed laser (usually nanosecond level, wavelength 1064 nm or 532 nm) is focused on the surface of the sample, generating a high-temperature and high-pressure plasma (temperature up to 10000-20000 K) in a very short time (<1 μ s). Under these conditions, micro level substances on the surface of the sample are instantly vaporized, atomized, and excited.

Subsequently, when the plasma cools, the excited atoms or ions will transition back to the ground state and emit characteristic spectra of specific wavelengths. Each element has its own "spectral fingerprint" - for example, iron has a strong emission at 358.12 nm, copper at 324.75 nm, and sodium at 589.0 nm.

Finally, by using a high-resolution spectrometer (such as a mid step grating+ICCD detector) to collect these optical signals, and utilizing database comparison and quantitative algorithms, rapid determination of the types and contents of elements in the sample can be achieved.

The entire process only takes a few seconds and causes almost no visible damage to most solid samples, truly achieving the goal of "shining a beam of light and knowing the composition of everything".

2、 Core technological advantages

1. True in-situ and on-site analysis capabilities

Without the need for sampling, digestion or compression, it can directly detect rocks, metals, soil, cultural relics, biological tissues, etc. Handheld LIBS devices can even operate in real-time in the field, mines, and accident sites.

2. Full element coverage

Almost all elements from light elements (such as Li, Be, B, C, N, O) to heavy metals (such as Pb, U, Hg) can be detected, breaking through the limitation of X-ray fluorescence (XRF) being insensitive to light elements.

3. Micro area analysis and in-depth analysis

The laser spot can be as small as 10-50 μ m, suitable for component mapping in small areas; By continuous pulse bombardment, layer by layer peeling can also be achieved, and the depth distribution of coatings, oxide layers, or corrosion products can be analyzed.

4. Suitable for various states of matter

Not only can it measure solids, but it can also analyze liquids (requiring special tanks), gases (such as plasma diagnostics), and even high-temperature molten metals.

3、 Typical application scenarios

1. Geology and Mining

Rapid screening of ore grade (such as Fe, Cu, Al content); On site imaging of core elements to guide drilling decisions; Planetary exploration: The ChemCam system carried by NASA's Curiosity rover, also known as LIBS, has successfully analyzed hundreds of Martian rocks.

2. Metallurgy and Metal Processing

Scrap metal sorting (distinguishing stainless steel grades 304 vs 316); Online monitoring of molten pool composition to optimize steelmaking process; Testing of Coating Thickness and Composition on Aircraft Engine Blades.

3. Environment and Safety

On site screening of soil heavy metal pollution (As, Cd, Cr); Identification of uranium and plutonium elements in nuclear waste; Rapid detection of explosive residues (including N, K, Cl, etc.).

4. Cultural heritage protection

Non destructive analysis of pigment composition in ancient ceramics, murals, and bronze ware; Identify authenticity, trace origin, and guide repair.

5. Biology and Agriculture

Research on the distribution of nutrient elements (K, Ca, Mg) in plant leaves; Analysis of the correlation between trace elements in animal bones and health.