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LohnStar Optics, a leading manufacturer of custom, highly-specialized IR thin film coatings for medical, research, industrial, military, and national space defense applications since 1997, has been serving the industry for over 20 years with a commitment to excellence and innovation. The company utilizes the latest computer software and state-of-the-art optimization techniques to meticulously design coatings that meet precise requirements. With advanced vacuum systems capable of accommodating optics up to 38 inches, they ensure high-performance and reliability in every application.

The company offers a variety of specialized optical coatings and services tailored for advanced applications.

• Ultra Low-Loss Supermirrors
  • Wavelength Range: 1µm to 14µm 
• Quantum Cascade Laser Coatings
  • Types: Anti-Reflective (AR), Broad Band Anti-Reflective (BBAR), Partial Reflective (PR), High Reflective (HR) 
• High Damage Threshold Coatings
  • Applications: CO₂ lasers, Er
  • lasers, high-power chemical lasers
  • Wavelength Range: 2µm to 16µm
• Sputtered Thin Film Filters
  • Wavelength Range: 250nm to over 50 microns
  • Special Materials: Diamond-like carbon coatings 
• Optics Fabrication
  • In partnership with fabrication and polishing associates
  • Accommodation: Optics up to 38" in size
  • Quantities: Small and OEM 
• Quality Assurance and Testing 
  • Spectral Verification: Using state-of-the-art spectrophotometers
  • Environmental Testing: Performed according to Mil-Spec standards
• Vacuum Calorimetry: Conducted as required

LohnStar Optics is known for its expertise in handling specialized coating demands, which is why many companies, researchers, universities, and government laboratories rely on them. Most of their business involves creating custom thin film coating designs for specialized applications. Using the latest and most effective coating technologies, tailored coater configurations, and advanced software, LohnStar Optics can address a wide variety of needs. Their chambers accommodate optics up to 38 inches in diameter, and they offer custom tooling fabrication services for optics in nearly any shape or size.

• Typical coatings:
  • Anti-Reflection
  • Bandpass Filters
  • Beam Splitters
  • Beam Combiners
  • Broadband AR
  • Cavity Ring Down Mirrors
  • Diamond-like Carbon
  • Dielectric Reflector
  • Dual Band AR
  • Enhanced Metal Coatings
  • Narrowband Filters
  • 90° Phase Retarder @ 10.6µm
  • 90° Phase Retarder@ 9.3µm
  • Partial Reflectors
  • Polarizing Beamsplitters
  • Protected Gold
  • Protected Silver
  • Quantum Cascade Laser Coatings 
  • Thorium-free Coatings 
  • Zero Phase Mirror @ 10.6µm 
  • Zero Phase Mirror @ 9.3µm
• Substrate Materials:
  • Aluminum
  • Beryllium
  • Calcium Fluoride
  • Chalcogenides (AMTIR, BD2, BD6)
  • Copper
  • Diamond
  • Fused Silica
  • Gallium Arsenide
  • Germanium
  • Glass
  • Infrasil
  • Indium Phosphide
  • Molybdenum
  • Nd:YAG
  • Nickel-plated Aluminum
  • Nickel-plated Copper
  • Sapphire
  • Silicon
  • Zerodur
  • Zinc Sulfide
  • Zinc Selenide 

AR Coatings

LohnStar Optics began offering anti-reflection (AR) coatings for CO₂ laser applications in 1997. Initially focusing on 10.6µm AR coatings, the company has since expanded its capabilities to include custom AR coatings for a wide variety of substrate materials.

With over two decades of experience, LohnStar Optics has developed expertise in coating common substrates like ZnSe, Si, FuSi, and Ge, as well as more uncommon materials such as GaSb, InP, and Diamond. The company's AR coating range now spans from 200nm to 50µm, including Ultra-Low Absorbing (ULA) AR Coatings, renowned for their performance at 10.6µm.

AR Coating Specializations:

Single Wavelength AR Coatings (V-Coat): 

These coatings are designed to target a single wavelength to enhance the throughput of optical systems. LohnStar Optics can produce these coatings for wavelengths ranging from 300nm to 20µm, optimized for reflectance below 0.25%. 

Dual-Band AR (DBAR) Coatings: 

DBAR coatings are engineered to target two specific wavelengths, often including one in the visible spectrum and one in the infrared. 

Broadband AR (BBAR) Coatings: 

These coatings are designed to cover an entire band of wavelengths. The specifications for BBAR coatings vary based on factors such as wavelength, angle of incidence, and polarization. 

Ultra-Low Absorbing AR (ULA) Coatings: 

ULA coatings are specifically optimized for use at 10.6µm. They are produced using special materials and a unique process to achieve extremely low absorption rates, less than 0.12%.

Beam Combiners 

Beam combiners merge two or more wavelengths of light, with one transmitted and another reflected, onto a single beam path. Substrate materials commonly used for beam combiners include ZnSe, ZnS, and Ge. The prevalent beam combiner design transmits an infrared beam, such as 10.6µm, while reflecting a visible beam, such as 633nm.

Beam Splitter 

A beam splitter is an optical device employed to divide an incoming light beam into two directions. It separates light by a power ratio between the transmitted and reflected components. Besides, beam splitters are capable of segregating polarization states and different light wavelengths. For tailored thin film coatings matching your precise requirements, reach out to the specialists at LohnStar Optics.

Cavity Ring-Down Mirrors 

The cavity ring-down mirrors are all-dielectric mirrors crafted through a proprietary process to achieve ultra-low losses due to scatter and absorption. These mirrors often exhibit reflectivity exceeding 99.99%, with scatter and absorption losses as low as ~10ppm, depending on the wavelength.

With over 20 years of expertise, LohnStar Optics has perfected a unique process to produce coatings with minimal losses from scatter and absorption. This advanced process, combined with extensive experience, allows the development of custom coating designs for ultra-low-loss mirrors suitable for cavity ring-down applications across wavelengths from 1µm to 15µm. Common substrate materials for these mirrors include Zinc Selenide, Silicon, and Fused Silica. Selecting the appropriate substrate material and specifications is crucial for optimal performance.

Metallic Mirrors

Protected Metal Mirrors:

Protected metal coatings feature a layer of highly reflective metal, such as gold, copper, or silver, with a dielectric overcoat to shield against oxidation and other potential damage. The protective layer also enables the mirror to be cleaned with solvents.

Enhanced Metal Mirrors:

Enhanced metal coatings consist of a layer of highly reflective metal, such as gold, copper, or silver, along with at least one pair of low and high index dielectric materials. These coatings boost the reflectivity of the chosen metal and can be optimized for virtually any wavelength in both the visible and infrared spectrums. 

Phase Retarding Mirrors (CO₂):

Phase Retarders, also known as 90° Phase Shift Mirrors, are used to convert a linearly polarized beam into a circularly polarized beam. These coatings are optimized for high power applications, with typical substrates being Silicon and Copper. 

• Standard Specifications:
  • Reflectivity at 10.6µm: > 99%
  • Phase Retardation: 90° ±3°

 Zero Phase Shift Mirrors (CO₂):

Zero Phase Shift Mirrors are designed to maintain the polarization state of the incident beam, typically a circularly polarized beam. These coatings are optimized for high power applications, with typical substrates being Silicon and Copper. 

• Standard Specifications for EM2:
  • Reflectivity at 10.6µm: > 99.6%
  • Absorption at 10.6µm: ≤ 0.20%
  • Phase Shift: 0° ± 2°

Output Couplers 

Output Couplers, also known as partial reflectors, are dielectric mirrors utilized in laser cavities to transmit a portion of the intracavity power. The backside surface is typically coated with an anti-reflective (AR) coating to minimize back surface reflection. Common substrate materials for Output Couplers include ZnSe, YAG, Ge, CaF₂, and Fused Silica (FuSi).

LohnStar Optics has established itself as a prominent manufacturer of custom IR thin film coatings, serving a wide array of sectors with precision and expertise since 1997. Through the utilization of cutting-edge software and optimization techniques, they ensure that each coating meets stringent requirements. Their advanced vacuum systems, capable of handling large optics, coupled with over two decades of experience, make them a reliable choice for any coating needs. Offering a comprehensive suite of specialized optical coatings and services, including Ultra Low-Loss Supermirrors, Quantum Cascade Laser Coatings, and Cavity Ring-Down Mirrors, they demonstrate their commitment to meeting diverse industry demands. With a focus on quality assurance and customer satisfaction, LohnStar Optics continues to be the preferred partner for organizations seeking tailored solutions for their optical needs.

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