At Knight Optical great care is always taken when cleaning optical components. The wrong cleaning solution can damage a delicate optic or coating and our highly trained team ensure the correct technique is used. Components are checked against a black background and a 60W lamp to ensure no dust or debris is on the surface. For small optics or products with very stringent cleaning requirements we will clean the part under an illuminated microscope to ensure the best possible results.
We understand that any process that involves contact with the optic always runs the risk of damaging it. With this in mind we will never clean an optic more than necessary and will always attempt to minimise handling throughout the process.
We typically use two different techniques to clean our products.
Acetone and cleaning solutions
...we use dilute, acetone, which is pH neutral for cleaning uncoated optical products where there is no risk of the solution degrading the surface. As a weak solvent, acetone breaks down dirt and other debris on the surface allowing it to be wiped away with a soft cloth. Proper use of acetone will leave no marks or streaks on the surface after cleaning. The optic is then visually inspected and packed directly to ensure no further contamination takes place.
Where there is a risk of our acetone solution causing damage to the optic we use a more diluted glass cleaning solution. This is generally the preferred option where soft materials such as calcium fluoride or delicate coatings such as gold.
Air and brushes
...some materials and coatings are unsuitable to be cleaned with a solvent solution. This is also the case for optical assemblies where the lens cannot be accessed with a cloth or if there is a risk of the solvent pooling in gaps in the assembly. In the first instance we will use canned air to fire a blast of at the optic in order to loosen or remove any surface debris.
In some instances this is enough to clean the optic to a good standard, however if this is not the case we will use a soft brush to sweep any remaining dust from the surface. Our brushes are designed specifically to minimise the risk of surface scratches and our staff are highly trained to ensure no parts are damaged during the cleaning process.
Knight Optical own a laminar flow cabinet for manufacturing and cleaning optical assemblies. This allows us to construct assemblies without risk of dust or debris being trapped between components. We also use this equipment for the cleaning of high specification optical components such as microscope objective lenses to ensure the best possible results before packaging.