ISO 9001 - AS 9100 - ITAR Standard & Custom Optical Filters and Coatings




How do you distinguish between an image quality and a commercial quality filter?

Image quality filters are ideal for applications that require high resolution, such as astronomical observations. To make these products, we polish high-quality optical glass to ensure the substrate is extremely flat and parallel, and then apply anti-reflective coatings on the external surfaces to reduce ghost images and maximize energy throughput. Commercial quality filters can have the same spectral characteristics as image quality filters, however they are designed for use in instruments rather than imaging applications.

What do I need to do to maintain my filters in good condition?

We recommend cleaning your filters about every three months. If the environment is particularly dusty or you often shift the filters between applications, more regular cleaning may be warranted. We suggest that you apply acetone, methanol, or alcohol to a soft tissue and then rub the filter using a circular motion.

Are there any particular environmental conditions to consider when using a filter?

It’s important to avoid prolonged exposure to high humidity and large temperature variations.To reduce the risk of damage due to thermal shock, we recommend a maximum operating temperature of 70°C and a maximum temperature change of 5°C per minute.

Do you offer custom or semi-custom sizes?

Yes. We have internal fabrication capabilities that allow us to completely customize your filter

When placing an order, why do I need to include the operating temperature?

The center wavelength of an interference filter shifts linearly with changes in ambient temperature. Our filter designs take this into consideration to ensure proper performance at your specific operating temperature.

When can I expect to receive my order?

Standard products ship within two to three days from receipt of order.

Do you offer discounts on surplus stock?

Andover offers generous price terms on our surplus inventory. Just visit our website at and plug in the desired wavelength to see what’s available.

Do you have a minimum order value / quantity?

No minimum value or quantity required.

How do I send custom specifications for quoting?

You can do this one of four ways:

  • Click HERE to Request a Quote
  • Email your request to:
  • Fax your specifications to 603.893.6508 Attn: Technical Sales Department
  • Call toll-free: 888-893-9992