Laser Mirrors & Lenses C02

Source: buythis.co.za/laser-mirrors-lenses-c02

• published: 2022-08-22 13:42:30
• modified: 2026-06-23 17:11:03

Links on the live page

The live page is a heading, a video search link and tiles that link to related CO2 laser sections:

• Laser Lens Videos
• CO2 Laser Tubes
• Accessories
• Desktop CO2
• Cabinet CO2
• Flatbed CO2
• Training

What this page is

buythis.co.za/laser-mirrors-lenses-c02 is the CO2 laser mirrors and lenses section of Buythis, AM.CO.ZA's online shop. On the live page it is only a heading, a link to laser lens videos and tiles to CO2 laser tubes, laser accessories, desktop, cabinet and flatbed CO2 lasers and RDWorks training. This knowledge base page explains what the mirrors and lens in a CO2 laser do and lists the CO2 optics and laser head parts on Buythis with their current prices (47 products in total). Fiber laser lenses and protective windows are a different wavelength and are covered on the fiber laser consumables pages, not here.

How the beam gets from the tube to the material

A CO2 laser tube makes an invisible infrared beam at 10.6 micron wavelength. On TruCUT and similar gantry lasers the tube sits at the back of the machine and the beam travels through the air to the cutting head:

1. First mirror. Mounted next to the tube output, it turns the beam 90 degrees along the Y gantry.
2. Second mirror. Mounted on the moving gantry, it turns the beam 90 degrees along the X axis towards the head.
3. Third mirror. Inside the laser head, it turns the beam straight down.
4. Focus lens. Below the third mirror, it focuses the beam to a small spot on the material. Air assist blows through the nozzle under the lens to clear smoke and protect the lens.

If any mirror is dirty or out of line, power is lost and the cut becomes uneven across the bed. That is why mirrors and the lens are the most common replacement parts on a CO2 laser, together with the tube itself.

CO2 focus lenses

Material. Most CO2 lenses are ZnSe (zinc selenide), which passes the 10.6 micron beam with very little loss and has an anti-reflection (AR/AR) coating on both sides. The premium versions marked P are made in the USA and last longer under high power. Germanium (Ge) lenses are a lower-cost option for small lasers up to 60W.

Focal length. This is the distance from the lens to the point where the beam is smallest. A short focal length (38.1mm) gives the smallest spot for fine engraving and thin material. The common 50.8mm (2 inch) lens is a good all-round choice for desktop lasers. 63.5mm (2.5 inch) suits cutting thicker acrylic and wood on cabinet and flatbed lasers, and 101.6mm (4 inch) keeps the beam focused through very thick material and is used on some metal-cutting heads. After changing the focal length, set the head height again so the focus point is on the material.

Diameter. The lens must match the holder in your laser head. Desktop lasers usually take 12mm to 20mm lenses, while cabinet and flatbed TruCUT heads take 20mm. Larger lenses also handle more laser power without overheating.

The CO2 laser lens guide on Buythis has a table of every diameter and focal length.

CO2 laser mirrors

Molybdenum mirrors are tough and can be cleaned often, so they suit dusty workshops and the first mirror, which sees the most heat. Silicon mirrors with a multi-layer dielectric film reflect the most power and are the usual choice for cutting work. Gold-plated K9 glass mirrors are a budget option for low-power desktop lasers up to 60W. Match the mirror diameter to your mounts: TruCUT desktop lasers use 20mm mirrors and cabinet and flatbed lasers use 25mm mirrors. The beam combiner lets the visible red dot pointer travel along the same path as the invisible beam so you can see where the laser will fire.

Laser heads and mirror mounts

Laser heads hold the third mirror, the focus lens and the nozzle. The nozzle length and lens holder set the focal length the head is built for, so choose the head that matches the lens you plan to use. Mirror mounts have adjustment screws used during beam alignment.

Cleaning and alignment supplies

Clean optics with lint-free wipes or buds only, never with paper towel or bare fingers, because scratches and finger oil absorb the beam and burn the coating. Beam test paper shows the burn mark of the beam at each mirror so you can check the alignment, and a line laser helps set the beam path visually.

Prices are current Buythis prices including VAT from the product dump dated 2026-10-20. Some prices come from slightly older dump entries (2026-10-17, 2026-10-18, 2026-10-19). Check the product page before ordering, since prices change.

How to choose and look after your optics

1. Measure what you have. Check the old lens diameter and focal length (often printed on the box, or measured as shown in the videos below) and the mirror diameter before ordering.
2. Pick the focal length for the job. 38.1mm for fine detail engraving, 50.8mm for general desktop work, 63.5mm or longer for thicker cutting.
3. Match the material to the power. Germanium lenses and K9 mirrors suit small lasers up to 60W. Use ZnSe lenses with silicon or molybdenum mirrors on higher power machines.
4. Fit the lens the right way up. The curved (convex) side of a plano-convex lens faces up towards the tube.
5. Clean often. Check the lens and mirrors weekly, or daily when cutting smoky materials like wood and MDF, and keep air assist on.
6. Align after any change. Re-check the beam path after changing a tube or mirror, or when the cut is strong on one side of the bed and weak on the other.

Videos

The live page links to a search for laser lens videos on the AM.CO.ZA YouTube channel. Videos about CO2 laser optics, focus and beam alignment:

• CO2 Laser Alignment Training, Align Three Mirrors and One Lens for Perfect CO2 Laser Cutting Result (2017-07-05)
• CO2 Laser Alignment Demonstration Video (2017-07-05)
• TruCUT CO2 Laser Alignment Training Tool Tested and Laser Beam Alignment Principle Explained (2017-08-13)
• Basic Steps for CO2 Laser Beam Alignment (2023-08-17)
• Install Laser Tube, Mirror and Lens, Laser Alignment and Service of CO2 Laser Cutting Machine 2021 (2021-11-27)
• How to Determine Laser Machine Lens Focus Length and Using Stocked Lenses to Compare Focus (2017-05-19)
• #SortIT, How to Measure CO2 Laser Focus Lens Focal Length and Diameter for Better Cutting (2020-01-28)
• Adjusting Laser Alignment and Mirror Cleaning on TruCUT PRO Laser Head with Capacitive Height Sensor (2017-07-07)
• Setup TruCUT 1000x600mm Short Cabinet Laser Machine and Performa Laser Beam Alignment at Lanseria (2022-02-21)
• TruCUT CO2 Laser Machine Installation, Raida RDWorks Controller, Laser Tube Wiring and Alignment (2022-09-21)
• How to Align The 2 Lasers on the MorCUT Cyclops CO2 Contour Cutter With 2 Beams (2024-09-25)

Related pages in this knowledge base

• CO2 Laser Lenses
• Laser Tubes CO2
• C02 Laser Tubes
• Laser Accessories
• Laser Machine Consumables
• Laser Desktop CO2
• Laser Cabinet CO2
• Laser Flatbed CO2
• Laser Machines
• TruCut
• Laser Cutter Mirrors and Lenses Have Arrived, Get Yours Now
• Laser Alignment is Always a Pain, Now We have a Training Course and Gear
• TruCUT CO2 Engraving and Cutting Machine Buying Guide with Highlights Features Explained
• Free Training Videos on Offer For Your TruCUT Laser Cutting & Engraving Machine!
• Crosshair Laser Alignment Kit with Magnetic Base for Easy Material Repeating Placement