Qu’est-ce qu’un laser fibre MOPA ?

Un laser fibre MOPA (Master Oscillator Power Amplifier) sépare l’oscillateur qui forme l’impulsion de l’amplificateur qui fournit l’énergie. À 1064 nm, on règle la durée d’impulsion, la cadence et l’énergie comme des paramètres distincts.

Quelle différence entre fibre Q-switch et fibre MOPA ?

Sur un Q-switch, la durée d’impulsion dépend souvent de la fréquence de répétition : plus on accélère, plus l’impulsion s’allonge et la puissance de crête baisse. Le MOPA découple ces grandeurs, ce qui aide le contraste sur plastiques, le recuit d’acier et les DataMatrix denses.

Le laser MOPA remplace-t-il un laser UV 355 nm ?

Non. Le MOPA reste à 1064 nm. Pour l’anodisation, le PVD, le DLC ou les plastiques très sensibles, le laser UV 355 nm reste le bon procédé. Le MOPA élargit les régimes de la fibre, il ne change pas la physique d’absorption.

Quelles machines NWS Laser embarquent une source MOPA ?

IK-SERIES MOPA pour l’intégration en cellule, robot ou ligne, et IK-BOX pour une station de marquage classe 1 en atelier.

NWS Laser EXPERTISE · FIBER MOPA

Tune the pulse,
not just the power.

A MOPA fiber laser (Master Oscillator Power Amplifier) separates pulse generation from amplification. This lets you select pulse duration, repetition rate and usable energy as independent settings — something a conventional fiber Q-switch doesn’t truly allow.

View parameters

WAVELENGTH 1064 nm PULSE
ADJUSTABLE

DEFINITION

Two stages,
one beam.

The master oscillator (seed) generates a short, defined pulse. The amplifier, an ytterbium-doped fiber pumped by diodes, raises the energy without reshaping the temporal profile. Isolators between them prevent back-reflections from damaging the seed. At the output: 1064 nm, galvanometric head, field lens. It is this separation that makes MOPA useful on the shop floor, not a “more power” slogan.

Diagram of a MOPA source: seed oscillator, isolators, ytterbium‑doped fiber amplifier, galvanometer head — Typical chain of a MOPA fiber marking source. The seed sets the duration; the amplifier sets the average energy.

WHY MOPA

The Q-switch ties
rate and duration.

In a Q-switched fiber the cavity and saturable absorber define an operating window. Increasing repetition frequency often lengthens the pulse and reduces peak power. Contrast on plastics, steel annealing or a dense DataMatrix can no longer be tuned independently.

Pulse duration

The seed allows pulses from a few nanoseconds to several hundred ns at a constant repetition rate. You can select the regime (ablation, superficial fusion, annealing) without changing the source.

Peak power

At a given pulse energy, shortening the pulse raises the peak. That is what yields higher contrast on some plastics and crisp metal marking without large thermal input.

Useful repetition rate

You can go into the kHz range for a DataMatrix or line-rate operation while keeping a short pulse. A conventional Q-switch often forces a compromise.

USEFUL PARAMETERS

What you actually
adjust.

Comparison of Q-switch and MOPA pulse trains at the same repetition rate, shorter pulses with MOPA — Same interval between pulses: the MOPA can remain narrower. The Q-switch often lengthens the pulse as frequency increases.

Qualitative curve: relative peak power versus pulse duration, at constant energy — At constant pulse energy, a shorter duration increases the peak. The ranges shown are shop-floor orders of magnitude, not a universal recipe.

SHOP FLOOR MAGNITUDES

Four knobs,
not black magic.

SettingWhat it changesTypical effect on part

Pulse durationTemporal width (ns)Clean ablation vs anneal / color

FrequencyPulses per secondCycle time, filling a code

Energy / average powerDeposited doseDepth, speed, burn risk

Scan speed and hatchingTrace overlapHomogeneity, roughness, OCR readability

Exact values must be qualified on the material / surface condition pair. Annealed steel is not comparable to glass‑filled POM, even at 1064 nm.

ON THE PART

What the MOPA
allows targeting.

1064 nm remains a near‑infrared laser: it heats and couples well to most metals, less so to some transparents. The MOPA advantage is the adjustment window, not a wavelength miracle.

Metals

Engraving, controlled oxidation, annealing. On stainless steel, a longer pulse and an adapted repetition rate can produce a dark contrast or interference colors. On aluminium, the aim is usually a light contrast by modifying roughness.

Engineering plastics

A high peak, short pulse limits polymer melting and favors blackening or whitening depending on additives (carbon black, TiO₂ ). Validate on the actual grade: an ABS is not a PEEK.

Traceability

DataMatrix, QR, serial numbers. High repetition rate helps fill a dense matrix without lengthening the pulse. Readability (grade, contrast, module) should be checked with the same workshop lighting.

Miniature laser marking on a pull‑tab spring — Small envelope: the galvo beam follows the part, not the other way around.

Electronic component marked with a fiber laser — Component: dose is set to stay in the housing, not in the silicon.

CHOICE GUIDELINES

MOPA, Q‑switch
or UV.

Reading spotFibre Q‑switchMOPA fiberUV 355 nm

Wavelength1064 nm1064 nm355 nm

Pulse durationLittle adjustableAdjustable, nsVery short, cold regime

Metal couplingGoodGood, more regimesUseful if the coating matters

Plastics / glassLimited, depending on additivesBetter contrast if high peakOften the right instinct

Coatings (anodizing, PVD)Risk of damaging the layerTo be qualified, rarely the first choiceUV laser territory

NWS LASER MACHINES

Where to house
this source.

INTEGRABLE

IK-SERIES MOPA

MOPA fibre source in an all‑in‑one enclosure, 24 Vdc, 8‑hole M6 mounting plate. For a cell, a robot or a line: the laser is integrated, a PC is not mandatory in production.

See the IK-SERIES datasheet

MARKING STATION

IK-BOX

Class 1 enclosure, electric door, galvo head on Z axis, Smart Vision. The MOPA source finds a workshop station there when the part comes to the machine, not vice versa.

See the IK-BOX datasheet

WORKSHOP QUESTIONS

Before purchasing
a pulse duration.

Does the MOPA replace a UV laser?: No. The MOPA remains at 1064 nm. For anodizing, PVD, DLC, rhodium plating or very sensitive plastics, the laser UV 355 nm remains the appropriate choice. The MOPA broadens the fiber; it does not change the absorption physics.
What pulse duration for stainless steel?: There is no single value. Colored annealing often requires longer pulses and dense hatching. Deep black contrast is achieved differently. Start with a test on the actual batch, not a public table.
Can you mark a carbon‑filled plastic?: Often yes, with a short pulse and a high peak to blacken without excessive melting. The grade, thickness and flame retardants alter the result. A sample of the compound is better than a generic material data sheet.
Is a PC required in production?: On IK-SERIES, up to 250 programs fit in memory. The PC is used to prepare files. In high throughput, the laser runs from I/O, encoder or PLC.

TEST ON PART

Send the material,
we tune the pulse on it.

Specify alloy or compound, surface condition, target code or logo, cycle rate. NWS Laser offers a MOPA trial on IK-SERIES or IK-BOX rather than a catalogue promise.

Tune the pulse,
not just the power.

Two stages,
one beam.