The impurities produced by zinc selenide (ZnSe) window lenses after coating and the appropriate cleaning methods are as follows:

Impurities produced after coating:

1. Organic pollutants:

Source: Photoresist residues, grease, fingerprints or environmental organic matter during the coating process.

Manifestations: Surface oil film, spots or mist-like residues.

2. Inorganic particles:

Source: Dust in the coating chamber, sputtering particles of the target material or dust during the handling process.

Manifestation: Tiny particles or scratches adhering to the surface.

3. Water stains or solvent residues:

Source: During the cleaning process, the pure water or solvent was not completely dried, leaving marks.

Suitable cleaning method: Weigot VGT-1509FH optical ultrasonic cleaner

Non-contact cleaning to avoid surface damage:

Zinc selenide is an infrared optical material with relatively high brittleness. Mechanical wiping is prone to cause scratches or surface damage. Ultrasonic cleaning achieves non-contact cleaning through the cavitation effect generated by high-frequency vibration, avoiding damage to the lenses caused by physical friction.

It is especially suitable for the protection of ZnSe surface coatings (such as anti-reflection films) to prevent the film layer from peeling off.

2. Efficiently remove sub-micron level pollutants:

The cavitation effect of ultrasonic waves can generate micron-sized bubble bursts, effectively removing particulate contaminants (such as polishing residues, dust) and organic contaminants (such as grease, fingerprints) on the surface of ZnSe.

For complex structures (such as the edges or grooves of lenses), ultrasonic waves can achieve all-round cleaning, avoiding blind spots in manual cleaning.

3. Controllable cleaning parameters are adapted to material characteristics:

ZnSe is sensitive to temperature and chemical solvents (such as being easily corroded by acidic or alkaline solutions). Ultrasonic cleaning can be precisely controlled.

Frequency (such as 40KHZ-100KHZ) : High frequency is suitable for precise cleaning, while low frequency is used for stubborn contaminants.

Temperature (usually ≤50℃) : Avoid ZnSe thermal stress or coating failure caused by high temperature.

Selection of cleaning agent: Use neutral or dedicated optical cleaning agents (such as anhydrous ethanol, deionized water) to prevent material corrosion.

4. Uniform cleaning to avoid secondary pollution:

The ultrasonic waves are evenly distributed in the cleaning tank to ensure consistent cleaning effects on all parts of the ZnSe lens surface and avoid the instability of manual operation.

After cleaning, water stains can be reduced through the built-in multi-stage rinsing and drying system (such as nitrogen blow-drying), lowering the risk of secondary pollution.

5. Automation and repeatability

Integrated automated processes (such as robotic arm handling) are suitable for batch processing, enhancing efficiency while ensuring consistent cleaning quality for each ZnSe lens, which is crucial for high-precision optical components.

6. Precautions for Use:

Power control: Excessively high ultrasonic power may cause micro-chipping (cavitation impact) on the ZnSe surface. Optimization is required based on the thickness of the lens and the coating condition.

Solvent compatibility: Avoid using solvents containing sulfur and chlorine to prevent chemical reactions with ZnSe.

The structural design of the optical ultrasonic cleaning machine produced by Weigute (such as adjustable frequency, temperature control system, and multi-tank process) enables it to be safe, efficient and consistent when cleaning zinc selenide lenses, making it particularly suitable for the high-standard cleaning requirements of infrared optical components.