Diode vs CO2 vs Fiber vs UV: Which Laser Technology Is Right for Your Workshop?

Every laser engraver or cutter uses one of a small number of laser technologies. The technology determines which materials the machine can process — not just which ones it does better. Understanding the physics of each laser type takes the guesswork out of machine selection and prevents costly mistakes when sourcing equipment for a specific application.

How Lasers Interact with Materials — The Core Principle

A laser is a focused beam of light at a specific wavelength. Whether a material is processed by that laser depends almost entirely on whether the material absorbs that wavelength. Glass is transparent to visible light but absorbs infrared. Aluminium reflects visible light but absorbs UV photons. Organic materials like wood and leather absorb broadly across wavelengths but particularly efficiently in the infrared range. This is why there is no single laser that processes every material equally well — the physics won't allow it.

Diode Lasers (450–455nm)

Modern desktop diode lasers use semiconductor lasers in the blue wavelength range. This wavelength is absorbed efficiently by most organic and dark-coloured materials and is the starting point for most xTool buyers.

Processes well: Wood, bamboo, leather, cork, rubber, fabric, paper, dark and opaque acrylic, anodised aluminium, painted surfaces. At 40W, cuts basswood up to 25mm.

Cannot process: Bare metal (reflected), clear acrylic (transmitted), glass (transmitted), white or very light acrylic (insufficient absorption).

The galvo diode advantage: When a diode source is paired with galvanometer mirror steering rather than a moving gantry, engraving speed leaps from 400–600 mm/s to 4,000 mm/s. This is the architecture of the xTool F1 and F2 — the same diode wavelength at dramatically higher throughput. For high-volume engraving on organic materials, galvo diode is the most cost-effective production technology available.

xTool diode machines: M1 Smart, M1 Ultra, S1 (enclosed, 20W/40W), F1 Portable (galvo), F2 (galvo).

Infrared Laser (1064nm)

At 1064nm, metal surfaces absorb the beam rather than reflecting it. This is the entry point to metal processing. IR modules at 2–5W (as found in the xTool F1 and F2) are specifically suited for marking bare metals — stainless steel, aluminium, brass, copper — and technical plastics and ceramics that diode lasers cannot mark cleanly.

In practice, most IR module users are jewellers, metalworkers, market traders doing personalisation, and sign makers who need occasional metal marking alongside organic material work. The dual-source architecture (diode + IR in one machine) makes this accessible without purchasing separate machines.

Fiber Laser (1064nm)

Fiber lasers also operate at 1064nm but at significantly higher power than IR modules. Where a 2W IR module marks the surface, a 20W fiber laser engraves deeply, marks with high contrast and permanence, and cuts thin sheet metal. The xTool F1 Ultra cuts stainless steel up to 0.3mm and aluminium up to 0.2mm — capabilities impossible with diode or CO2 technology.

Combined with galvo steering at 10,000 mm/s, the F1 Ultra processes metal jobs at speeds that make commercial production volumes viable from a desktop machine. Fifty engraved metal tags that would take hours on a gantry take minutes on the F1 Ultra.

MOPA Fiber Laser

MOPA (Master Oscillator Power Amplifier) fiber lasers provide independent control over pulse width and frequency — parameters that standard fiber lasers cannot separate. This unlocks three capabilities unavailable in standard fiber:

• Full colour spectrum on stainless steel: Different pulse widths produce different oxide thicknesses, producing different visible colours. Blue, gold, purple, red, and true black are all reproducible and permanent without pigments.
• True black on bare aluminium: Standard fiber produces grey marks on aluminium. MOPA's short pulses produce genuine black oxide — the industry standard for aluminium part marking.
• Coating-precise removal: MOPA removes coatings without thermal spread into the substrate — essential for electronics, precision instruments, and complex coated surfaces.

The xTool F2 Ultra's 60W MOPA is competitive with industrial fiber systems at a fraction of the cost. For businesses where colour marking on metal is a core product offering, MOPA is the correct technology.

CO2 Laser (10,600nm)

CO2 lasers emit at 10,600nm — far infrared. Organic materials absorb this wavelength with extremely high efficiency. The result is decisive cutting power on wood, acrylic, leather, paper, and fabric that diode lasers cannot match at comparable wattage. A 55W CO2 cuts 18mm basswood in a single pass; a 40W diode requires multiple passes on the same thickness.

CO2 also produces a flame-polished edge on cast acrylic — optically clear, smooth, requiring no post-processing. This is why CO2 is the standard technology for sign shops, furniture makers, and acrylic fabricators.

Cannot process: Bare metal. The 10,600nm wavelength reflects off metal surfaces entirely.

xTool CO2 machines: P2S (55W), P3 (80W with AI fire detection).

UV Laser (355nm)

UV lasers at 355nm operate through photochemical ablation — high-energy photons break molecular bonds directly, removing material without significant heat generation. This is categorically different from thermal laser processing and enables applications no other laser technology can achieve.

3D inner glass engraving: The UV beam focused inside transparent glass creates micro-fractures within the material volume — building 3D structures suspended inside glass or crystal objects. Crystal trophies, personalised glass blocks, and premium glassware decoration require this technology and nothing else.

Heat-sensitive materials: Electronics, precision plastics, silicone, and coated surfaces that thermal lasers melt or discolour are marked cleanly by UV's cold processing mechanism.

Ceramics and porcelain: Fired ceramic surfaces receive clean, burn-free marks without the thermal cracking risk of infrared lasers.

xTool UV machine: F2 Ultra UV (5W, 15,000 mm/s via galvo, dual 48MP cameras).

Technology Decision Matrix

Application	Correct technology	xTool machine
Cutting thick wood, acrylic, leather	CO2	P2S or P3
Engraving and cutting organic materials	Diode	S1 40W or M1 Smart
High-speed batch engraving on organics	Galvo diode	F2 (15W + 5W IR)
Marking bare metal	Fiber or IR	F1 Portable or F1 Ultra
Colour engraving on stainless steel	Fiber (20W+)	F1 Ultra
Industrial colour + deep metal marking	MOPA (60W)	F2 Ultra MOPA
3D inner glass, ceramics, cold processing	UV	F2 Ultra UV
Vinyl cutting + laser in one machine	Diode + blade	M1 Smart or M1 Ultra
Print + cut (colour printing on hard surfaces)	Diode + inkjet + blade	M1 Ultra or M2 Color Craft

Available from Eolas Prints

Eolas Prints is an authorised xTool reseller based in Cantabria, Spain, offering the complete xTool range across all laser technologies. Contact us with your material and application requirements — we'll identify the correct technology and machine before you spend.