Optical Filters Capabilities - Overview

Established in 1967, Newport's Optical Filter business has been supplying Corion® brand optical filters and coatings for nearly 50 years. Originally founded as a business to manufacture analytical instruments based upon optical filter technology, the company switched its focus in the early 1970's from instruments and filters to optical filters, only. Today, we utilize more than 25 optical coating chambers performing a wide variety of coating technologies including Hybrid Plasma Deposition, e-Beam Evaporation, and Resistance Thermal Evaporation and covering a spectral range from 200 nm to 8 um to manufacture precision optical filters as well as assemblies and optoelectronic devices based upon optical filters.

We manufacture a wide variety of products based upon thin-film coating technology. Our products span the spectrum from 150 nm to 16 µm. Our major product families include:

Anti-Reflection Coatings Bandpass Filters Dichroic Filters Edge Filters
Gain Balancing Filters Fluorescence Filters Neutral Density Filters Notch Filters

Coating Technologies

Stabilife® Technology
Stabilife® optical filters and coatings are manufactured using a patented process for the deposition of metal oxide thin film optical coatings using sputtered Hybrid Plasma Deposition (HPD). This process yield highly dense, thin film coatings with extraordinary hardness, abrasion resistance, and adhesion to the substrate. Our Stabilife® processes were developed at our Corion coating facility in Franklin, Massachusetts, where these products are manufactured.

Many applications for exposed hard coatings do not require the spectral stability provided by our Stabilife® processes. These are the applications for unassisted E-beam deposition. E-beam deposited refractory metal oxide coatings are extremely durable and can be designed to meet the spectral needs of optical components ranging from bar code reader filters to dental lighting mirrors.

Resistance Thermal Evaporation
Resistance Thermal Evaporation encompasses the widest range of coating materials and deposition methods of all of the technologies currently in use for the manufacture of optical coatings and is perhaps the most flexible in terms of ability to achieve extreme technical requirements. It is the most seasoned of all of the technologies and as such, methods of protection of the “soft films” produced using this technology are so highly evolved that in many environments, the difference in product life between a protected soft coating and an exposed hard coating is imperceptible.

Key Benefits of Stabilife Coatings

Film Density & Spectral Stability
Stabilife® coatings have a higher packing density and lower void ratio than un-stabilized metal oxide coatings and are therefore less affected by water absorption. Unlike un-stabilized metal oxide coatings which can experience spectral shifts in the range of 2-5% of wavelength, Stabilife® coatings typically exhibit total wet-to-dry shifts of less than 0.02% of wavelength.

Thermal Properties & Spectral Stability
Stabilife® films are typically 5 to 10 times less sensitive to thermal variation than un-stabilized metal oxide films as a result of film densification.

Physical Durability
Stabilife® filters have been qualified for telecommunications applications per the requirements of Telcordia GR-2883. In the course of normal production, Stabilife® films are tested for adhesion using the snap tape test specified in MIL-C-48497, for abrasion resistance using the eraser test specified in MIL-C-675, and for humidity resistance using the aggravated test specified in MIL-STD-810E. Stabilife® thin-film optical coatings require no additional protection such as hermetic sealing using lamination or other processes, to achieve their exceptional durability.

Typical Stabilife Bandpass Specifications

Bandwidth (FWHM)0.5 nm to 4 nm5 nm to 20 nm20 nm to 200 nm
Center Wavelength (CWL)300 nm to 2 µm220 nm to 2 µm220 nm to 3 µm
CWL Tolerance (% of FWHM)± 20%± 20%± 10 to 20%
Peak TransmittanceUp to 90%Up to 98%Up to 98%
Out-of-Band BlockingOD4 to OD6OD4 to OD8OD4 to OD8
Cavities (typical)2 to 33 to 54 to 8

Typical Stabilife General Specifications

Spectral Range220 nm to 3.0 mm
Surface QualityF/F (80/50) per MIL-F-48616 (typical); D/C (40/20) or C/B (20/10) achievable
Coating HardnessMIL-C-48497
Coating Abrasion ResistanceMIL-C-48497
Coating AdhesionMIL-C-48497
Coating Humidity ResistanceMIL-STD-810, Method 507.3, Procedure III, Modified to 40 cycles**
Coating Operating Temperature Range-100°C to 300°C
Filter Size Range1 mm to 300 mm
Filter Thickness Range 0.5 mm to 20 mm

**The specifications for humidity resistance and coating operating temperature range listed above apply to exposed coatings only. Humidity resistance and operating temperature range of filters manufactured using Stabilife® coatings and assembled using epoxy systems revert to the humidity resistance and operating temperature range of the epoxy system

Filter Construction

Unlike some manufacturers that are limited by the nature of their coating processes, we provide several options for filter construction, which in some cases such as fluorescence detection instrumentation, can make the difference between a filter that meets the requirements for lowest autofluorescence and one that does not. Our filter construction methods include:
Hard Coating - Single Element - Spectrally Stable
Filters constructed using this method consist of Stabilife® hard filter coatings, on a single substrate.

Hard Coating - Multi-Element - Laminated to Assemble
Filters constructed using this method consist of Stabilife® hard filter coatings, on one or more substrates, that are laminated together with a moisture resistant epoxy solely for the purpose of assembling multiple filter elements together to form the completed assembly. This method also enables the addition of non-thin-film elements to the construction to achieve desired performance.

Hard Coating - Multi-Element - Mechanical Assembly
Filters constructed using this method consist of Stabilife® hard filter coatings, on one or more substrates. In this construction method, filter components are assembled together to form a completed filter assembly using machined holders and mechanical retaining hardware.

Hard Coating Construction - Spectrally Dynamic Coatings Hard Coating - Single Element - Spectrally Dynamic
Filters constructed using this method consist of conventionally deposited hard filter coatings, on a single substrate. These filters will exhibit spectral shifting as ambient relative humidity changes but will be designed and verified to meet all spectral requirements at the specified operating conditions.

Hard Coating - Multi-Element - Laminated to Stabilize/Assemble
Filters constructed using this method consist of conventionally deposited hard filter coatings, on one or more substrates. Lamination with a moisture resistant epoxy after coating may serve two purposes in this construction method including elimination of the short and/or long term humidity induced spectral shifting inherent in these types of coatings and bonding of multiple components to make the completed assembly.

Soft Coating - Scribed & Laminated
Scribed & Laminated Soft Coating construction is a commonly used construction for bandpass and edge filters. Filter components are coated onto separate substrate plates. These plates are then scribed to remove the film symmetrically around the required specified active film areas of the filters to be produced from the plate. The scribed plates are subsequently laminated together with a moisture resistant epoxy. A glass-epoxy-glass seal is formed in the scribed areas forming the best possible barrier to moisture penetration. Filters are cut through the scribed area to their finished size using diamond cutting tools.

Soft Coating - Argon Gap
This construction is typically used for filters which will be exposed to high levels of solar or ultra-violet radiation. These filter components are then assembled into specially designed holders using a proprietary sealing process that eliminates the sources of solarization by-products. No epoxy sealants are used in the process.

Flexibility / Scalability / Prototype-to-Production

We process orders for quantities as large as one million and as small as one and we maintain one of the highest customer satisfaction ratings in the process. We have coating chambers that coat 1 - 6” square plate at a time and chambers that coat 16 - 6” squares at a time. We design products for optimized manufacturability and conduct prototype development of those products in the coating chambers that will ultimately be used for series production of those products, thereby insuring fidelity of the prototyping process.