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A Brief History of LIBS and Laser-OES Terminology
The technique now known as Laser OES (Laser Optical Emission Spectrometry) / LIBS (Laser-Induced Breakdown Spectroscopy) originated in the 1960s and 1970s, following the rise of the Laser. Over time, it has also been referred to by other names, including LIPS (Laser-Induced Plasma Spectrometry) and LSS (Laser Spark Spectrometry)—all describing essentially the same underlying method.
In the early days, there was no standard terminology. Terms like Laser-OES, LIPS, LSS, and LIBS were all in circulation as scientists explored how lasers generate plasma and how to analyze the emitted light. Since the field was still emerging, a single, widely accepted name had yet to take hold.
Much of the foundational work during this period was led by pioneers such as L.J. Radziemski and C.M. Cremers, who were instrumental in developing the experimental techniques and demonstrating the potential of laser-induced plasmas for elemental analysis. Their research laid the groundwork for Laser OES / LIBS as a practical analytical method.
By the 1980s and 1990s, LIBS became the dominant term in scientific literature. It clearly conveys the key concept: a laser pulse causes optical breakdown, creating a plasma whose light reveals the material's elemental composition. The term also helped distinguish this method from other laser-based techniques.
Today, LIBS remains the preferred term in research settings. However, in industrial contexts, Laser-OES is commonly used, as it aligns better with familiar techniques like spark-OES and ICP-OES. This naming helps practitioners in manufacturing and analytical labs more easily relate the method to existing processes.
Status today:
The terms LIBS (Laser-Induced Breakdown Spectroscopy) and Laser-OES (Laser Optical Emission Spectroscopy) both describe basically the same method: a pulsed laser creates a small plasma on the sample surface, and the light emitted from this plasma is analyzed to identify elements. However, in industrial and applied analysis, Laser-OES is a clearer and very useful term because it fits better with the existing family of OES techniques.
Common OES Technologies and Their Basics
In optical emission spectroscopy, several important methods are widely used in industry and labs. They are often named after the way plasma or excitation energy is generated:
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Spark-OES: This method uses a high-voltage electric spark to excite atoms in a solid metal sample. The spark creates a hot plasma on the sample surface, causing the elements to emit light at characteristic wavelengths. Spark-OES is widely applied for rapid and reliable elemental analysis of metals and alloys in production lines and quality control, especially in the steel and automotive industries. It is known for good precision and the ability to analyze many elements simultaneously.
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Arc-OES: Arc-OES uses an electric arc—similar to an electrical discharge—to excite atoms in powders, pressed pellets, or solid samples that are difficult to analyze by spark. The arc generates a plasma with sufficient energy to atomize and excite elements, which then emit light characteristic of their atomic structure. This method is useful in metallurgy and materials science when analyzing powders or non-metallic solids, offering an alternative where Spark-OES is less effective.
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ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy): ICP-OES creates a very high-temperature plasma (around 10,000 K) by coupling radio-frequency energy into argon gas. This plasma can atomize and excite nearly all elements in liquid samples with high sensitivity. ICP-OES is highly versatile, allowing simultaneous multi-element analysis with low detection limits, making it a standard technique in environmental monitoring, chemical laboratories, and pharmaceutical quality control. Its robustness and broad elemental range have made it a gold standard for liquid sample analysis.
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GD-OES (Glow Discharge Optical Emission Spectroscopy): GD-OES uses a low-pressure glow discharge plasma to sputter atoms directly from the surface of a solid sample. The sputtered atoms are excited in the plasma and emit light, allowing surface-sensitive elemental analysis and depth profiling. This makes GD-OES highly valuable in coating analysis, thin film characterization, and failure analysis in materials science. Its ability to perform fast depth profiling sets it apart from other OES methods.
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MIP-OES (Microwave-Induced Plasma Optical Emission Spectroscopy): MIP-OES uses microwave energy to generate a plasma, typically at lower power and temperature than ICP. It is well suited for detecting light elements such as phosphorus, sulfur, and halogens, as well as some metals. Although it has higher detection limits compared to ICP-OES, MIP-OES is a cost-effective alternative in applications where ultra-high sensitivity is not required. It finds use in industrial process monitoring and quality control where moderate detection limits and lower operating costs are acceptable.
Other Emission Spectroscopy Methods Outside This Naming
Two techniques do not fully fit the OES naming scheme:
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Flame Emission Spectroscopy (FES): FES excites atoms in a sample using a flame, such as a Bunsen burner. It is widely used in teaching laboratories to demonstrate elemental emission colors (e.g., sodium’s yellow, potassium’s violet). While simple and inexpensive, FES suffers from relatively poor sensitivity and can only reliably detect a few elements like sodium, potassium, and calcium. Due to these limitations, its role in modern industrial analysis is very limited, mostly replaced by more sensitive and versatile methods.
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LIBS: Although LIBS is technically an optical emission spectroscopy technique, its use of a laser pulse to create plasma differentiates it from traditional methods. LIBS can analyze solids, liquids, and gases directly without sample preparation, providing rapid, multi-element detection with minimal or no contact. Despite these advantages, the term “LIBS” is mostly used in academic and research contexts, which sometimes separates it from industrial OES technologies. The term Laser-OES highlights the connection to OES, making it more understandable and acceptable for industrial users.
Why we think “Laser-OES” Should Be Used
The term Laser-OES fits naturally within the family of OES techniques. Most principles of spectral emission, calibration, and interference handling are the same as for Spark-OES or ICP-OES. The main difference is in the energy source: laser pulses instead of electrical sparks or radio-frequency plasmas.
Using Laser-OES improves clarity and communication in industrial environments where multiple OES methods are in use. It also supports the growing application of laser-based emission spectroscopy in areas such as raw material testing, recycling, process control, and quality assurance.
Conclusion
Although LIBS and Laser-OES describe the same technique, Laser-OES is the preferred term in industrial and applied analytical settings. It integrates the method clearly into the family of OES technologies, facilitating knowledge transfer and supporting its wider adoption in industry.
