G&H operates four facilities with thin film optical coating capabilities: two in the US and two in the UK; each with multiple chambers. We offer customers temperature stable optical coatings to meet high laser damage thresholds at short pulse lengths across the bandwidth of commercial laser wavelengths from deep UV through to far IR.
Our expertise in coating has been supported by investment in custom built, ultra-clean, high repeatability chambers to meet customers’ evolving needs for environmentally-stable optical coatings. Our engineers are continuously researching the performance characteristics of new coating materials and integrating the results into our modelling software to optimize the designs for customers’ applications.
We have a comprehensive range of coating techniques:
- Thermal evaporation
- Electron-beam (e-beam)
- Ion assisted deposition (IAD)
- Ion beam sputtering (IBS)
A chamber that incorporates thermal, e-beam and an ion source provides increased coating flexibility. This enables us to tune and allow selective bombardment of the various coating materials during deposition to match challenging substrate types and meet exacting performance requirements.
We use thermal evaporation for deposition of metals and dielectrics which are less compatible with e-beam coating. For the many materials that are compatible however, the e-beam technique provides coating with lower stress where surface flatness is a priority, higher laser induced damage threshold (LIDT), and improved control of impurities in the deposited material.
E-beam is especially useful for coating components for operation at deep ultraviolet and infrared wavelengths.
Ion assisted electron beam (IAD) coating deposits robust coatings with very high laser induced damage threshold (LIDT) and very low thermal shift.
IAD coatings are widely utilized for optical systems designed for the defense industry where multiple laser wavelength devices are required to work together in rugged environments.
Ion beam sputtering (IBS) generates very dense, hard coatings ideal for very high reflection and low loss requirements. IBS is thus well-suited to finishing superpolished mirrors – whether for cutting edge research or for Ring Laser Gyros (RLG). IBS coatings have a lower LIDT than IAD coatings. to work together in rugged environments.
|Deposition Technology||Coating Types Offered|
|Electron beam gun evaporation (e-beam)|
|Ion assisted e-beam deposition (IAD)|
|Ion beam sputtering (IBS)|
As part of the quality control process, we test our coated
optics using the following processes:
- Temperature cycling, adhesion, abrasion and
humidity testing to ISO and MIL standards.
- Transmission measurements made using
spectrophotometers with wavelengths from 300 nm
to 28 µm.