GLOSGLOSSARY
Laser marking glossary.
Definitions, not jargon.
A working reference for the terms you’ll see across our capabilities, quality, and documentation pages. Written for engineers, buyers, and quality managers who want a quick technical lookup — not a sales sheet. 34 entries across four categories.
01MARKING PROCESSES
Annealing
- A laser marking technique that heats the surface of a metal — typically stainless or titanium — without removing material. The localized heat induces a controlled oxide layer that produces a permanent dark mark. Passivation-friendly; preferred for medical and surgical instruments where corrosion resistance must be preserved.
Laser Etching
- A subtractive marking process that ablates a thin layer of substrate or coating to produce a high-contrast mark. Common on anodized aluminum, where the etched modules expose the underlying base metal beneath a colored anodic layer. Faster than deep engraving but shallower.
Deep Engraving
- Removal of substantial substrate material to produce a recessed mark visible by feel and by raking light. Suitable for tool, die, and mold identification where marks must survive heat treatment, repeated handling, and cleaning. Depth is built up in controlled passes.
Serialization
- The application of a unique identifier — typically a sequential serial number paired with a 2D Data Matrix code — to each part in a batch. Foundational to traceability programs, recall management, and lot-level genealogy.
2D Data Matrix
- A two-dimensional matrix barcode, typically encoded with ECC-200 error correction. High data density per unit area makes it the preferred format for direct part marking on small components. Commonly graded against ISO/IEC 15415.
Direct Part Marking
DPM- The application of a permanent identifying mark directly to the part itself — as opposed to a label, tag, or adhesive. Required for traceability across cleaning, heat treat, and service environments where consumable identifiers would be lost.
02LASER TECHNOLOGY
MOPA
Master Oscillator Power Amplifier- A fiber laser architecture that decouples pulse generation (master oscillator) from power amplification. Allows independent control of pulse width and pulse frequency, which is what enables clean color marking on stainless, low-thermal annealing, and precise contrast tuning across substrates.
Fiber Laser
- A solid-state laser in which the gain medium is an optically pumped, rare-earth-doped optical fiber. Emits at a near-infrared wavelength of 1064 nm, which couples efficiently into metals. The dominant laser type for industrial marking due to its reliability, beam quality, and long source life.
Pulse Width
- The duration of each laser pulse, measured in nanoseconds (ns). MOPA platforms tune pulse width across a wide range — typically 2–500 ns. Short pulses minimize the heat-affected zone for fine detail; longer pulses drive deeper ablation.
Pulse Frequency
- The repetition rate of laser pulses, measured in kilohertz or megahertz. Also called the repetition rate. Independent control of pulse width and pulse frequency is the defining capability of MOPA fiber lasers.
Beam Quality
M²- A dimensionless measure of how closely a laser beam approaches an ideal Gaussian profile. M² = 1.0 is the theoretical ideal; values below 1.5 are typical of high-quality industrial MOPA fiber lasers. Lower M² produces a tighter focused spot, finer detail, and cleaner walls in deep engraving.
Galvo Scanner
- A pair of motorized mirrors (galvanometers) that steer the laser beam across the marking field. Standard 2-axis galvos move the beam in X and Y; 3-axis galvos add a dynamic Z-focus lens for true 3D marking on contoured surfaces.
F-theta Lens
- A flat-field focusing lens used after the galvo to focus the steered beam onto a flat marking plane. Lens focal length determines the marking field size — common options range from 70 mm to 300 mm square.
03STANDARDS & COMPLIANCE
MIL-STD-130
- The U.S. Department of Defense standard governing identification marking of items entering DoD supply chains. Specifies syntax, encoding, legibility, and registration of Item Unique Identification (IUID) marks.
MIL-STD-129
- The U.S. Department of Defense standard for marking military shipments: the identification that goes on unit packs and exterior shipping containers so the items inside can be received, stored, and issued without opening the box. Current revision is MIL-STD-129R. Distinct from MIL-STD-130, which governs the mark on the item itself; the two share data, including the UIIs of IUID-marked items.
PDF417
- A stacked linear 2D barcode symbology. MIL-STD-129R uses it on unit pack and exterior container identification labels to encode the contract number, CLIN, shipment number, CAGE, part number, quantity, serial numbers, and UIIs, per Appendix A, Table A-IV of the standard.
Item Unique Identification
IUID / UID- A unique, machine-readable identifier registered with the DoD’s IUID Registry. Required for items meeting cost or program thresholds under MIL-STD-130. Typically encoded as a 2D Data Matrix carrying a Unique Item Identifier (UII).
Unique Item Identifier
UII- The globally unique string derived from the data on a MIL-STD-130 IUID mark: issuing agency code, enterprise identifier, and serial number (Construct 1), with the original part number or lot number between them in Construct 2. Limited to 50 characters from A–Z, 0–9, dash, and forward slash. The UII is the same whether the mark is encoded in Format 06 or Format 12.
UII Construct 1 / Construct 2
- The two ways MIL-STD-130 builds a UII. Construct 1 serializes within the enterprise: enterprise identifier + serial number. Construct 2 serializes within the original part number, lot, or batch: enterprise identifier + part or lot number + serial number. Construct 2 is the usual path for manufactured parts.
ISO/IEC 15434
- The message syntax that wraps the data inside a MIL-STD-130 Data Matrix: the header [)> and an RS character, a two-digit format code, data elements separated by GS characters, and an RS EOT trailer. MIL-STD-130 permits Format 05 (GS1 application identifiers), Format 06 (data identifiers), and Format 12 (text element identifiers).
Format 06
Data Identifiers / DI- The ISO/IEC 15434 format that qualifies each data element with an ASC MH10.8.2 data identifier: 17V for CAGE, 12V for DUNS, 1P for original part number, 1T for lot, S for serial within the part number, and 18S or 25S for a UII carried as a single element. The most common format on DoD contract UID labels.
Format 12
Text Element Identifiers / TEI- The ISO/IEC 15434 format that qualifies each data element with an ATA Spec 2000 (A4A Common Support Data Dictionary) text element identifier, written as three letters and a space: MFR, CAG, or SPL for CAGE, DUN for DUNS, PNO for original part number, SEQ for serial within the part number, SER or UCN for serial within the enterprise. Used on aerospace programs that mark to Spec 2000. Never mixed with data identifiers in one symbol.
CAGE Code
- Commercial and Government Entity code: the five-character alphanumeric identifier assigned to suppliers to the U.S. government. The most common enterprise identifier in a UII, carrying issuing agency code D.
UID Label
- An adhesive label or data plate carrying the MIL-STD-130 IUID Data Matrix and its human-readable information, used when the item cannot take a direct part mark. Commonly laser-marked on dual-layer acrylate stock such as 3M 7847 or tesa Secure 6973, where the mark is ablated into the facestock rather than printed on it.
ISO/IEC 15415
- The international standard for grading 2D barcode print quality. Evaluates symbol contrast, modulation, axial nonuniformity, grid nonuniformity, and unused error correction. Marks are graded A through F.
AS9132
- The aerospace industry standard for direct part marking. Provides guidance for marking that survives cleaning, inspection, and service cycles without damaging the substrate or introducing crack-initiation sites.
FDA UDI
Unique Device Identification- The U.S. FDA framework for marking medical devices with a unique identifier. Combines a device identifier (DI) with a production identifier (PI), encoded for both human and machine reading. Compatible with passivation and autoclave cycles.
ECC-200
- The error-correction encoding scheme used by modern 2D Data Matrix codes. Reed-Solomon based, allowing reliable decoding even when up to roughly 30% of the symbol is damaged or obscured.
Certificate of Conformance
CoC- A document accompanying a finished part or batch attesting that the work was performed to specified parameters. Typically includes substrate, process settings, operator, date, and the read-back result for each code.
04QUALITY & VERIFICATION
Verification Grade
- The graded result of reading a 2D code with a calibrated camera-based verifier per ISO/IEC 15415 (or AIM DPM-1-2006 for direct part marks). Grades A and B are typically required for IUID and aerospace programs.
Symbol Contrast
- A grading parameter measuring the difference in reflectance between the dark and light modules of a 2D code. Higher contrast yields more reliable scanning, particularly with inexpensive readers and in poor lighting.
Modulation
- A grading parameter measuring the consistency of reflectance across all modules in a 2D code. Low modulation indicates inconsistent ablation depth, contamination, or surface variation.
Grid Nonuniformity
- A grading parameter measuring how far each module deviates from its ideal position on the symbol’s theoretical grid. High grid nonuniformity signals fixturing drift or galvo calibration issues.
Passivation
- A chemical post-process that restores the corrosion-resistant chromium oxide layer on stainless steel after machining or marking. Annealing marks are passivation-friendly because they don’t remove substrate; etched or engraved marks may require passivation to restore corrosion resistance.
SEEN A TERM YOU NEED?