Hard Dielectric Coatings for Laser OpticsLASER COMPONENTS GmbH, Olching
The company stopped being a sole distributor in 1986 when it started its own in-house production of hard dielectric coatings for laser optics and laser rods. It was not long before the name LASER COMPONENTS ranked among the top suppliers of optics in the laser industry. Well-known laser manufacturers count on our optics, which cover the complete spectral range from 193 nm (UV) to 5 µm (MIR).
Inside our specially-developed, high-vacuum chambers containing an electron beam gun, we coat both our own as well as substrates supplied by customers with diameters ranging from 4 to 200 mm. Furthermore, our machine shop manufactures holders for substrates with special sizes. Rush jobs can be done within 24 hours upon request.
The department has five such coaters. One of these coaters uses sputter technology which allows us to manufacture even better optics for the next generation of lasers. Some of our specialties include the manufacture of glass parabolic mirrors for thin disk lasers, adaptive optics, and Gaussian mirrors.
The E-beam process, also referred to as the PVD process (Physical Vapour Deposition), is the most commonly used coating technology in the field of laser technology. Due to their fast layer growth and flexible capacity, coatings can be produced with high damage thresholds at reasonable prices.
Features. With this process it is possible to produce cw/fs coatings in addition to various high power coatings. This is achieved through the deposition of different materials.
The modified coating can affect the bandwidth, dispersion behavior, scatter losses, and the damage threshold.
For applications in which high levels of power are used and in which a low wavelength drift, high mechanical resilience, or low dispersion layers are required, we recommend applying the IAD (ion-assisted deposition) process. Moreover, IAD coating has the advantage that it can be performed at low temperatures, which makes it possible for sensitive substrates or optical fibers to be coated.
Depending on coating requirements, two different IAD sources are available at LASER COMPONENTS:
An ECR source (electron cyclotron resonance) predominantly delivers ions in the range of under 100 eV. Because of the relatively (to the cold cathode sources) low ion energy, the coatings produced with this source have a low remaining porosity. This allows high damage thresholds to be achieved, particularly in the nansosecond range.
Alternatively, a cold cathode source is available that provides energy in the range of up to 200 eV, through which extremely compact layers can be produced that completely avoid water retention. Layers of this kind are characterized by just a marginal thermal drift.
Online Monitoring System
In addition to layer thickness control through oscillating crystals and monochromatic optical detection, LASER COMPONENTS also has an optical broadband monitoring system available.
During the coating process, the entire visible spectrum is monitored and the layer thickness precision increased to over 0.1%. This makes the production of complex coating systems significantly easier.
In conjunction with the low drift layers of the IAD coating process, this monitoring system can expand the product spectrum and significantly increase the reliability of the coating process.
With its help we are able to coat high power laser optics in such a compact way that the water virtually has no chance of embedding itself. With process temperatures of less than 100 °C it is also possible to equip fully assembled fibers, plastic lenses, and glued and assembled optics with a hard, laser-proof coating.
IBS Sputter Coating
Ion beam sputtering (IBS) is an extremely precise and reproducible coating method. Unlike in any other coating technology, process parameters, such as application of energy, layer growth rate, and oxidation level, can be independently and exactly regulated. This leads to compact layers with the lowest possible wavelength drift.
Sputter Coatings Process
In the sputtering method, noble gas ions are shot at the coating material. The impact of the ions disperses the material, which subsequently settles on the substrate to be coated.
Due to their extremely high kinetic energy the impacting particles are very mobile. This mobility aids in the filling of holes and the avoidance of any defects in the growing layer.
This ultimately leads to the formation of exceedingly smooth and, in their optical properties, particularly homogeneous layers. Using this coating method several hundred layers may be placed on top of each other, creating optical coatings for selected requirements.
- Lowest scatter loss and very high reflection (R > 99.99 %)
- High packing density, no water retention, and thus extremely low temperature drifts
- Smooth surfaces with marginal roughness
- “Cold“ coating method and thus suitable for temperature and moisture-sensitive substrates,
- nonlinear or laser crystals and laser diodes
- Stable and reproducible process for complex layer designs such as, for example, in steep edge filters