JML Optical provides precision-engineered custom optical solutions. To meet the needs of various industries, we offer a wide range of products, which include aspherical, cylindrical, spherical, and plano/flat glass fabrication. From our state-of-the-art lean manufacturing center, our skilled team of engineers provides rapid prototyping, design, and fabrication services for every stage of the production process. JML Optical serves many sectors, including aerospace, defense, medical devices, automotive, imaging, semiconductor, and entertainment.


JML Optical uses a variety of high-quality glass and non-glass materials to build specialized optical solutions for our clients. We use non-glass materials as structures—such as lens barrels—to hold the glass optical components. Different materials are selected according to system requirements.


Aluminum is a lightweight, strong, and versatile material well-suited for optomechanical assemblies. Its low density is ideal for lighter structures. Its high strength-to-weight ratio ensures that these structures can withstand the rigors of use. Aluminum also has a low coefficient of thermal expansion, which ensures it maintains its shape and size over a wide range of temperatures.


Stainless steel is a heavier material than aluminum, but its coefficient of thermal expansion is even lower. This makes it ideal for use in optomechanical assemblies that require dependable performance over a wide range of temperatures. Stainless steel is also resistant to corrosion.


Some metals are easier to machine to tighter tolerances than others. Brass is an excellent example of this. With good mechanical characteristics, corrosion resistance, and malleability, brass is a popular choice for optomechanical assemblies.


Our optical glass is extensively used in digital devices such as cell phone cameras, digital cameras, LCD projectors, and other advanced optical assemblies. Our materials are also ideal for optical devices such as astronomical telescopes and microscopes. To support our environmentally-friendly initiatives, JML Optical develops and fabricates ecologically safe glass types, free of lead and arsenic. The two main types of optical glass we work with are crown glass and flint glass:

Crown Glass: Crown glass is an optical glass found in lenses and other optical products. It has low dispersion and a low refractive index. Crown glass is made from alkali-lime silicates containing about 10% potassium oxide.

Flint Glass: This is an optical glass with a high refractive index and a lower Abbe number, from 50 to 55 or less. Their refractive indices range between 1.45 and 2.00.


We use vapor-phase axial deposition to create our synthetic fused silica. This process produces ultra-pure and bubble-free materials. We also provide natural quartz from high-quality crystals, including hydrous and anhydrous quartz with high heat resistance and low bubbles.


Many low-expansion glasses have an ultra-low coefficient of thermal expansion. Our low-expansion glasses are made under highly controlled conditions and feature excellent mechanical, thermal, and chemical characteristics. These optical components maintain their shape and size over a wide range of temperatures.


At JML, our optical designers consider many factors when choosing glass for a project. The three primary optical properties are refractive index, dispersion, and transmittance. Each of these properties affects how light travels through the glass and how the final image appears. Our designers also consider the material properties of the glass, including its coefficient of thermal expansion and chemical and mechanical properties.


JML Optical is your one-stop shop for optomechanical design, glass and metal fabrication, rapid prototyping, metrology, thin-film coating, environmental testing, and assembly. Regardless of your intended optical application, it is crucial to consider the material properties of the glass. Even if the material properties are not critical to the optical design, certain materials can make lens fabrication more or less difficult or expensive to produce. For example:

  • Softer glasses are more easily scratched, so they can also be more challenging to make at a scratch-dig cosmetic level of 20-10 or 10-5.
  • Harder glasses take longer to polish for a given surface figure error specification. This may raise production costs.
  • Glasses that stain easily need more expensive treatments to prevent staining.

Because of the friction and heat generated from working the glass, higher CTE glasses tend to deform more. Before being measured by precision metrology, these optical components may need to be cooled to room temperature first, which can add time and slow production.

When building assemblies, glasses with low transmittance in the ultraviolet range may limit the use of UV-cured adhesives.

The type of optical glass used has a major influence on the cost of production and the quality of the final product. JML Optical considers all these material properties when designing and manufacturing optical devices. Contact us today or request a quote to learn more.