We’ve recently published an article in our newsletter about an increase in demand for our mirror reworking service. This isn’t just idle boasting, it is a result of OEMs dramatically cutting support for installed CO2 lasers, including a big reduction in stocks of spare parts.
This is probably because the bulk of current OEM production is now focused on fiber lasers, therefore support for existing CO2 laser users has been cut. So at LBP we’ve seen a corresponding increase in demand for laser mirror repairs, not just for truly obscure mirrors but for parts that were standard and widely available just 2 or 3 years ago.
We regularly repair, polish and coat a wide range of mirrors, including copper and molybdenum, to a ‘good as new’ condition, saving our customers time and money.
Some of our aerospace and automotive customers insist we offer a RTV (Return To Vendor) repair programme to reduce the overall cost of ownership of laser equipment. It saves time, money and valuable materials, and is well worth doing. The reworked mirrors are as good as new so there is no loss of quality or productivity. It can also contribute to ISO 14001 Environmental Management Here’s a great case study…
One of our customers, a European automotive manufacturer, sent us a collection of used mirrors from their production line that had accumulated minor burns and scratches, and had been swapped out. They were large, complex water cooled beam delivery mirrors which we repolished and recoated to a condition that was as good as new. The mirrors were repaired and returned in under 3 weeks.
The customer was delighted and told us the mirrors were working perfectly, and had saved them $15,000 on the cost of new mirrors!. They have since had them reworked three more times.
Here’s an example of another customer’s mirrors that we reworked to a ‘good as new’ condition. These were from a gas sensing cell made by a company who stopped supporting their equipment. You can find out more on our website.
It’s not widely appreciated how easy it is to distort a laser mirror with mechanical forces that can be generated from inadvertently over-tightening mounts, or water fittings. Although our experience is mostly with metal mirrors such as copper or aluminium, we know glass mirrors are just as sensitive to distortion. Sometimes the distortion is elastic, so the surface figure is restored when the mechanical force is removed. Often though the distortion can be permanent. We recently repaired a water cooled mirror for a customer that was very thick ( 33mm ) and looked to be in good condition.
By reflecting a high mode quality visible laser beam from the mirror at 45 degrees incidence we could see the distortion the mirror introduced into the reflected beam profile. Using our phase shifting interferometer we could resolve a 2-3mm diameter convex ‘pip’, perhaps just a micron or so high, in the centre of the mirror. This is where the surface had been ‘punched through’ by the mounting screw in the rear of the mirror.
There was 16 mm thickness of solid copper between the bottom of the screw hole and the mirror face. Despite this though, it was still possible for the mechanical force from tightening of the mounting screw to permanently distort the mirror face.
The hot spot created in the reflected beam by the mirror distortion when used with a CO2 laser would have likely caused damage to other optics, such as the focus lens.
We will be in Munich again this year showcasing our range of all-metal mirrors for science and research, as well as our now well-established mirror reworking service.
We’ll be showing a wide range of our mirrors including Gold coated Copper, Aluminium, Molybdenum, Stainless Steel and Tungsten. Most of these materials have excellent broad reflectivity across the mid infra red, and are ideal for many infra red applications. They are highly durable and resistant to harsh environments such as those found in gas sensing and infrared spectroscopy.
With an excellent range of reflective coatings covering the spectrum from UV to THz, we have an unrivalled range of products which can be seen, and handled, at this years show. Suitable for CO2 laser cutting and welding, fiber laser applications, Dental and Medical Er:YAG lasers, QCL sources, fiber lasers and even Terahertz applications our mirrors are regularly supplied for both low volume prototype and high volume production parts. Customers include industrial laser users, OEMs, Academics and Research Institutes around the world.
LBP’s customers worldwide are also regularly saving thousands by repairing mirrors back to operational condition after damage by exposure to chemicals and harsh environments. Examples of ‘before’ and ‘after’ mirrors will be on display.
We seem to have had a bit of a surge in demand for diagonal, or elliptical flat mirrors recently. We have just made some diagonal mirrors from gold coated copper with a diagonal angle of 60 degrees. When viewed at 60 degrees they have a circular profile. We have also made similar all metal mirrors from Stainless Steel for Laser Induced Breakdown Spectroscopy. Stainless Steel is generally used uncoated. Last, but not least as it is a great application for our laser mirrors, some small gold coated copper mirrors for Er:YAG surgical laser handpieces.
With surgical lasers, left-handed surgeons can have great difficulty using surgical equipment designed for right-handed surgeons, or when being trained by right-handed instructors. With lasers at least, it’s possible to use a mirror to “flip” the beam paths and allow right handed and left handed use.
Gold coated copper mirrors for Er:YAG laser
Stainless steel diagonal lipstick mirrors
The first diagonal metal mirror was probably made by Isaac Newton in 1668, juts a few miles from our factory here near Cambridge. It was the secondary mirror in the worlds first telescope to use reflective optics.