Reflective apertures, stops and shutters

Sometimes a high power infra red laser needs to have its power attenuated, or have strongly diverging modes removed from the beam. At Laser Beam Products we manufacture mirrors with precision through holes or with sharp knife edges that are very cost effective, even when made to your design as a one-off prototype.

We usually advise customers that the length of the hole is no more than the hole diameter, to avoid having a “tunnel” with an aperture at either end. We can make tapered holes to avoid this problem. Because our Gold coating is applied electrochemically the internal bore of any hole is also Gold coated.GoldPrismHoleFlippedIf an acousto-optic modulator (AOM) is being used, a reflective aperture can be used to manipulate one of the beam orders to be reflected and the other to be transmitted. We can make through holes as small as 1 mm diameter very accurately.

Stainless_Steel_Prism

 

 

Advertisements

Laser World of Photonics New Delhi 9-11 September 2015

We’re busy preparing for the next Laser World of Photonics show in India. We were G21_5impressed with the show last year in Bangalore so we’re hoping it will be just as good this year in New Delhi.

If you’re visiting come and visit us in the UK pavillion, Booth number G21. We’ll be showing a range of our products including gold coated copper and aluminium mirrors with a range of optical coatings and sizes from as small as 5mm diameter.

Resistant to harsh environments our mirrors have high laser damage thresholds and are used in many applications including gas sensing, medical and dental lasers, fiber lasers, high power pulsed and CO2 laser cutting and infra red counter measures.

LBP manufacture a wide range of standard and bespoke parts with a range of optical coatings covering the spectrum from UV to THz as well as infrared. Full details are available on our website.

Uncoated Copper Laser Mirrors

We had a good opportunity to compare the performance of our gold coated copper mirrors with uncoated copper mirrors recently. A customer sent us dozens of large water cooled mirrors from his 6KW CO2 laser to re-manufacture. The workplace environment of the laser cutting system had dulled and corroded the bare copper mirror surfaces. Simply handling the mirrors had caused stains on the mirror face. In comparison a gold coated mirror, from exactly the same laser, had barely changed it’s appearance, or performance.

gold coated infrared mirror

Uncoated Copper laser mirrors or Gold coated ?

We’ve also recently helped customers in tropical climates who had problems with copper mirrors corroding, even in storage. Moisture reacts with exposed copper to cause pitting and staining, and even penetrates through pinholes in dielectric coatings. Several OEMs are now specifying mirrors should be Electroless Nickel plated, so no part of the mirror is exposed copper. This is already the case with all of LBP Copper mirrors. Copper can also diffuse into metal mirror coatings deposited on it; to prevent this a diffusion barrier such as Electroless Nickel should be used.

Max R coated Copper mirror

Copper diffusing into laser mirror coating causes failure

Some of our competitors are now warning that copper mirrors should be kept absolutely dry, which is simply impossible if they are to be used. Especially as most of them are water cooled!

There is more information about Electroless Nickel coating of mirrors on our website

Laser Beam Products at Photonics West 2015

?????? It’s that time of year again and we’re preparing for our next trip to San Francisco for the Photonics West exhibition from 10-12 February 2015. If you’re planning to visit, pop by and see us at the British Pavilion, Booth 5117.

As well as exhibiting our core range of metal mirrors, we will also be looking to talk to customers who want to make their own coatings on our low scatter metal substrates. Although we offer our mirrors with a range of coatings for use with soft UV, visible, IR and even THz wavelengths, there are times when our customers want to make their own coatings.

We will provide the mirror substrates super polished, cleaned and ready for further coating. Most of our mirrors use an amorphous layer of electroless nickel much favoured by coaters, as there are no issues with oxidation, staining or complex vacuum packing restrictions. It’s not just optical coating either, we have customers specifying functional coatings chosen for their hardness, magnetic or electrical properties.

 

Cleaning of CO2 laser optics

We know that CO2 laser optics will obtain a level of contamination during use and we often get asked by our customers what is the best method for cleaning them.  Keeping your optics as clean as possible will help to prolong their lifetime, and so save yourself the cost of a replacement, and possible machine downtime.

A few years ago we decided to look in to this in more detail and issued a white paper on the subject. You can find it on Laser Beam Products website and it is free to download. It gives you some clear guidance as to which type of solvent and cleaning method will be most appropriate for your particular type of optic. It also explains how best to avoid unnecessarily damaging or scratching the surface of the optic during cleaning. There are quite few of these guides to cleaning optics available on the web, and we should say not all agree with our method, but this is based on 25 years practical experience.

It should be read alongside our experiments identifying what contamination can do to CO2 laser optics

If you have any thoughts on this, or any questions, please get in touch, we’d like to hear about your experiences, both good and bad!