Coatings

  • Ion Assisted Deposition (IAD) process
  • Advance Plasma Source (APS) plasma-ion assisted Deposition
  • Anti-Reflection Coatings
  • High Reflection Coatings
  • Coatings on Optical Fiber

OptoSigma supplies a wide selection of optical thin film coatings. These coatings are often provided as part of the optical component but they may also be ordered separately to be applied to an uncoated element. For example, it is possible to apply an AntiReflection coating to any uncoated lenses, windows or optical fibers. Also reflecting coatings may be applied to uncoated substrates to form mirrors or partial reflectors. To make this process simple we have listed some of our most common standard coatings. To order you simply append the coating suffix to the base part number and specify the surfaces to be coated. If you don’t find the exact coating you need please ask us to provide you with a custom solution. Our coating engineers will use the latest design software and production techniques to provide you with the coating you require.

Optical thin film coatings are used to control the intensity, wavelength selection and polarization characteristics of incident electro-magnetic radiation. For laser and precision optical applications the quality of the coating is critical. Coatings must be precise as well as durable and damage resistant. OptoSigma’s advanced IAD and advanced plasm source (APS) coating facility in Santa Ana, California is able to supply high performance laser coatings covering the optical spectrum from 190 to 3000nm.

Anti-Reflection Coatings

  • Lenses
  • Windows
  • Optical Fiber Endfacesr

We offer a wide range of Anti-Reflection coatings which may be applied to any of our glass or fused silica lenses or windows to reduce reflection losses. Through use of our Ion Assisted Deposition (IAD) process we also specialize in AR coatings on optical fiber endfaces. Low temperature IAD coatings may be applied to most fiber endface terminations. Pre and post coating inspection is performed in our dedicated facility to ensure high quality. Our “Super-V” Coatings represent the ultimate in low reflection coatings (R<0.1%) for narrowband applications. We also offer laser line V Coatings, Broadband Multilayer AR Coatings, Multiband AR Coatings, Telecom AR Coatings and Single Layer AR MgF2 Coatings. Standard coatings may be ordered by simply appending a coating suffix to the product number and specifying the number of sides to be coated. For more complex requirements we suggest that you call - our applications engineers will be pleased to advise you on the best coating for your needs. Standard Anti-Reflection coatings are listed in the following table.

Specifications & Tolerances

On BK-7 Substrates: Super V: R<0.1% per surface at designated wavelength V Coating: ( ­λ<325nm) R<0.5% per surface at designated wavelength V Coating: ( λ>325nm) R<0.25% per surface at designated wavelength Multiband AR: R<0.25% per surface at designated wavelengths Broadband AR: R<0.6% per surface over the designated range MgF2 AR: R<2.5% per surface over the designated range Durability and Laser damage threshold depend on the substrate so please see the later sections of this catalog for these specifications. The curves on the following pages show typical single surface reflectance for each of the specified coating types.

High Reflection Coatings

We offer narrowband and broadband dielectric high reflecting coatings as well as a range of metal coatings. Laser Line HR Coatings are offered for all major laser wavelengths in the range of 193 to 2100nm. Broadband HR Coatings are offered for a selection of bandwidths. They provide a very high degree of spectrally neutral reflection and represent the ultimate in optical mirror coatings. Most of the coatings listed are for use at 45 degrees angle of incidence, but we do offer a selection of Broadband, Normal Incidence HR Coatings. Other normal incidence coatings can be provided on special request.

Specifications & Tolerances

  • Narrowband Laser HR: ( λ=193nm) Rav >95% for 45° incidence at designated wavelength
  • Narrowband Laser HR: ( λ>193 and <300nm) Rav >95% for 45° incidence at designated wavelength
  • Broadband HR: (45°AOI) Rav>99.0% for 45° incidence over designated bandwidth
  • Durability and Laser damage threshold depend on the substrate so please see the product sections of this catalog for these specifications
  • The curves show typical average reflectivity for a selection of our standard coatings.

Custom Optical Coatings

  • High, partial, and anti-reflection
  • Edge, notch, band pass filters
  • Plate and cube beam splitters
  • Wavelength ranges 190 – 2500nm
  • Sizes up to 10 x 10 inches
  • Various angle of incidence and polarization requirements
  • OptoSigma and customer furnished materials
  • Optical glasses, crystals, polymers, fibers, fiber assemblies, and cemented substrates
Here at OptoSigma we specialize in custom optical coatings from the ultra-violet to the near infrared. Every day we provide a variety of custom coatings from simple modifications of the catalog specifications to entirely specialized designs.

If the custom coating design is straightforward, we will perform a single test run immediately before the production run. For more complicated designs, a development process will be needed to establish the specifications which can be met in a production environment. This could potentially include multiple test runs, design modifications, and data analysis. We work closely with our customers through every step in the process to determine which specifications are suitable for both their applications and a manufacturing environment. It is in the best interest of OptoSigma and our customers to get through the development stage and on to production as quickly as possible. Once production is reached, the specialized processes and inspection are documented and established to ensure ongoing success.

Broadband All Dielectric

All dielectric multi-layer coatings are much more durable and of higher optical performance that those which involve metals. These can be offered with almost zero absorption and reflectivities greater than 99%. The all dielectric design is limited to a specific spectral bandwidth around the center design wavelength. Large bandwidth requirements demand the use of high precision coatings. These types of coatings are performed regularly at OptoSigma. Two actual spectral curves demonstrating this type of coating can be seen in the following plots.

Wide Angle

Particular applications demand the use of all dielectric coatings due to their durability and superb optical performance. The all dielectric design is however highly sensitive to angular variation, which can create problems for broadband applications involving large angular variations, such as those with non-collimated beams or rotating substrates. To accommodate the need for angular variation, a coating bandwidth substantially greater than the source bandwidth is required. This requires a highly precise all dielectric coating. Two actual spectral curves demonstrating our capabilities follow.

Anti-Reflection Specifications & Tolerances

Substrate material: BK7 Grade A Angle of incidence: 0 degrees / %R <0.3: 1250-1650nm

High Reflector Specifications & Tolerances

Substrate material: BK7 Grade A Angle of incidence: 0 degrees / %R ave >97.0: 400-1000nm

Reflector Specifications & Tolerances

Substrate material: BK7 Grade A Angle of incidence: 40±15degrees / %R ave >98.0: 450-650nm

Cube Specifications & Tolerances

Substrate material: BK7 Grade A Angle of incidence: 45±5degrees %T p >98: 780nm / %T s <1.0: 780nm

Filters

Many standard types of custom filters, such as short wave pass, long wave pass, multiple notch, and band pass filters are manufactured at OptoSigma. In addition, a variety of highly customized coatings which do not fall into a general category are produced regularly at OptoSigma. Our engineers design to the specific targets established by our customers’ needs. The designs are then tested in our chambers and we work closely with our customers to arrive at a final manufacturable coating. Two actual spectral curves demonstrating our capabilities follow.

Specifications & Tolerances

Substrate material: BK7 Grade A Angle of incidence: 45 degrees
%T <3.0: 532nm %T >85: 488, 632.8, and 1064nm

Specifications & Tolerances

Substrate material: BK7 Grade A Angle of incidence: 0 degrees Region 1: %T <5.0: 425-525nm
Region 2: %T >90: 590nm Region 3: %T = 20±10: 670nm Region 4: %R >99.0: 1064nm