Precision Optical Machining

Imagine peering into a human cell, navigating its intricate structures with incredible detail. Or, envision a powerful telescope capturing the light of distant galaxies, pushing the boundaries of human discovery. These remarkable feats are achieved partly through the magic of precision-machined optical components.

These components are the building blocks of advanced optical systems, crafted from a diverse range of materials each chosen for its unique properties. From the crystal-clear lenses that bring the world into focus to the intricate mirrors that guide laser beams with pinpoint accuracy, the right material makes all the difference.

What Are the Materials for Optical Machined Components?

The materials used in components manufacturing for optics vary widely based on the application, performance requirements, and environmental conditions. Some common materials include glass, polycarbonate, quartz, metals, and more.

• Glass: Widely used for lenses and other optical systems due to its excellent transparency and ability to be precisely shaped.
• Polycarbonate: Common in vision glasses and some consumer electronics due to its high impact resistance and optical clarity.
• Quartz: Preferred for laser applications and other high-precision optical devices because of its thermal stability and low coefficient of thermal expansion.
• Metals:
  • Aluminum: Frequently used for lens housings and stages due to its lightweight and good machinability.
  • Steel: Chosen for its strength and durability in various optical device components.
  • Titanium: Utilized in military and aerospace applications for its strength, light weight, and corrosion resistance.
• Plastics: Various high-performance plastics are used for light-blocking gaskets, lens mounts, and other components that do not require the optical properties of glass or quartz but need precise machining.
• Specialty Materials:
  • SOMABLACK: Used for light-blocking applications due to its excellent light absorption properties.
  • Optical Coatings: Materials such as anti-reflective coatings, protective layers, and other specialty coatings enhance the performance of optical components.

What Are the Methods of Machined Optics?

With a high demand for optical precision components, the methods used by precision optical machining experts focuses on the type of devices needed along with the types of optics and supporting components. Optics and optical components are key to so many industries and consumer products. Your cell phone is a great example of the use of optics and the high-quality optical precision component manufacturers achieve. An obvious user of machined optics is your optometrist and all the devices those medical professionals utilize in diagnosis and treatment. There are cameras used for municipal traffic control, optics used in hunting, for surveying, for home monitoring and so many other applications. Some component manufacturing for optics will use techniques for creating high-precision optical components by removing material from a solid block using specialized machinery. Other methods will cut through materials to high precision. As the available technologies differ in their capabilities, here are some of the common methods for machined optics, along with industry examples:

Methods Used in Optical Machining:

• CNC Turning and Milling: Turning is suitable for cylindrical shapes, while milling allows for creating flat surfaces and features on various geometries. Lens housings, mirror housings, stages mounts, optical adjustment mechanisms, and aperture stops are some examples.
• Ultra Precision Machining: This technique utilizes computer-controlled machines with very high precision to create complex, non-rotationally symmetrical shapes. It’s suitable for intricate components like diffractive gratings, freeform lenses, and microfluidic channels. By using diamond cutters, 3D optics are created for plano, aspheric, spherical, conformal and freeform optics.
• Diamond Turning: This method uses a diamond cutting tool to create smooth and highly accurate surfaces on rotationally symmetrical components like mirrors, lenses, and scanner mirrors.
• Laser Cutting: This technology uses ultraviolet and fiber lasers to cut through materials for 2D profiles. Examples made in support of optical precision components are lens stops, aperture stops, and light blocking gaskets.

Additional Examples of Optical Components:

• Consumer electronics: Smartphone cameras, projectors.
• Defense and Aerospace: For guidance systems, telescopes, and targeting systems.
• Automotive: Many automobiles have lidar technology. These devices require optics to function with clarity and without distortion.
• Medical Industry: Optics used in the medical field are not only used for research, but for diagnosis and treatment of patients. Endoscopes and laser surgery equipment are examples.

Precision optical machining in many industries and applications require manufacturers to adhere to guidelines like ISO 9001-2015 for Quality Management, ASTM International for material standards and quality management, Mil-STD-1349 (mostly required by the military but can be adopted by commercial manufacturers). For environmental considerations there are guidelines such as RoHS (Restriction of Hazardous Substances). Optics used in electronic devices need to comply with RoHS regulations. REACH (Registration, Evaluation, Authorization and Restriction of Chemicals): REACH focuses on the safety of chemicals used in manufacturing processes. Optical precision components manufacturers need to ensure their practices comply with REACH regulations. As demand increases, optical component manufacturers and optical component distributors work within these regulations to provide the highest quality available. With the support of subcontractors, the optics industry has only a bright future in sight. Pun intended.

What is the Optical Machining Process?

Manufacturing precision optics and supporting components undertakes multiple technologies and processes to produce the high quality we experience today. Like many of the advances in technology we use and sometimes take for granted, the origins have often been forgotten. Optics and optical devices were first used thousands of years ago and is believed that Mesopotamians and Egyptians polished crystals, possibly quartz to use be used for magnification, beginning around 700 BC. The 13^th century witnessed early glasses made of quartz. The early lenses were handheld or placed in frames of wood and sometimes bone. In 1608, a Dutch spectacles maker named Hans Lippershey, is credited with developing the first telescope and this would be followed by in 1609 with Galileo Galilei, using a telescope to record his observations of celestial objects. These early inventions and progress for optics were done by hand and took much time to perfect. The skills of those individuals were highly sought after and regarded. Over these millennia, progress in all aspects of human existence can be attributed in part to technological advancements. Components manufacturing for optics and optical supporting components are made at an extremely high level for consumer, science, medical, industrial, and defense/aerospace applications. The production of optics can be divided into two manufacturing sectors with one focusing on the optics of the lenses and light focusing elements and the supporting components like lens housings, aperture stops, device cases and so many more. As this industry is vast and does include multiple sub-contracting categories, the following is an overview of the machining process for optics and supporting optical components.

Machined Optics

• Material Selection: Optical precision components are made for the application needed. Glass is common for lenses and optical systems while polycarbonate is widely used for vision glasses. For industrial applications, quartz is chosen for laser applications.
• Raw Material preparation: The raw material is cut down to be processed for machining.
• Machining: Depending on the material precision optical machining can be done with CNC turning and Milling, diamond turning and other ultra-high precision techniques.
• Refinning Processes: Grinding, polishing and coating are done to shape and adjust the optics to the desired dimensions or perhaps prescription. This is where the optics become clear and exact.
• Testing and Quality Control: As in all manufacturing industries, the standards are high for optics. It must be to provide the necessary vision needed by consumers, for transportation to recognize potential flaws or obstructions to surgeons performing lifesaving medical procedures. The testing of the optics is done and checked by measuring devices.
• Production Manufacturing: Once given the approval to proceed, manufacturing at production volumes can ensue. These can be mid to high levels that optical precision components manufacturers adjust to depending on the demand.

Optical Machined Components

Precision optical machining is done for many applications in support of optics, optical devices, and systems. The geometry can be very simple like flat 2D shims to complex 5 axis machined components. The manufacturing process is similar to manufacturing optics but does have some key differences.

• Material Selection: Material choice is often used for the qualities and characteristics it has. For a stage or lens housing, machined steel or aluminum might be used. For a light blocking gasket a material called SOMA Black would be a good choice. For a military application perhaps, titanium is needed for strength and weight considerations.
• Programed Data: Much of modern manufacturing is controlled by computers. This allows for precise control of the selection of the right tools and control on how they are used. For many optical components, CNC technology (Computer Numeric Control) is used.
• Machining: There are numerous ways to manufacture optical precision components by CNC technology:
  • CNC Drills- Used to create holes, slots, and other geometry. Cutting through or programed depths.
  • CNC Lathes- Rotating the material while blades cut the shape. Good for cylinders and similar shapes.
  • CNC Milling- Used in 3,4, and 5 axis machines. Can produce very complex parts.
  • CNC Routers- Sheets of materials are cut and drilled by this method.
  • CNC Laser Cutting- Also good for cutting sheets of materials, especially in thinner gauges.
  • CNC Plasma Cutting- Used for industrial applications and can cut many material types.
  • CNC Waterjet- Using high-water pressure and abrasives can cut various materials with no heat affect.
  • CNC machined components can be produced with a very tight tolerance of +/- .025mm or .001”. This again is repeatable and necessary for volume production.
• Quality Control: Like precision optics, supporting components go through quality control checks to ensure the parts are made to the dimensions and standards required. Once approved the production proceeds.
• Finishing Processes: Many metallic materials require a finishing process such as anodizing, powder coating, electropolishing, paint and other coating options. These serve multiple purposes such as adding corrosion resistance, protection from wear and for aesthetic appeal.

Advancements in optics and optical systems have been attributed to our understanding of the universe and our home on planet Earth. We utilize optical systems and other technologies, to measure the geology and how natural and man-made forces affect the environment. Optical precision components manufacturers make support devices that can give sight again to those who have diminished capacity and give our medical professionals tools to better diagnose and treat diseases. The cooperation of new optics designs and optical manufactures along with their subcontractors has and is continuing to create the breakthroughs we are currently experiencing. What new advancements these will have on medical, consumer, aerospace, transportation and so on, is unknown, but it is exciting to be a part of with a bright future for precision manufacturing.

What Are High Precision Optical Components?

High-precision optical components are not your average lenses or mirrors. High precision optical components are critical elements in advanced optical systems, offering exceptional accuracy and performance. These components are manufactured with tight tolerances and high-quality standards to ensure optimal functionality in their specific applications.

• Diffractive Gratings: Used in spectroscopy and laser systems to separate light into its component wavelengths with high precision.
• Freeform Lenses: These lenses have complex, non-symmetrical shapes designed for specific applications, providing superior performance over traditional spherical lenses in certain optical systems.
• Aspheric Lenses: Utilized to correct aberrations in imaging systems, offering better focus and clarity than spherical lenses.
• Microfluidic Channels: Tiny channels used in lab-on-a-chip devices for medical diagnostics and research, requiring extremely precise machining to ensure proper fluid flow and interaction.
• Mirror Assemblies: High-precision mirrors used in telescopes, laser systems, and other optical instruments to direct light with minimal distortion.
• Optical Filters: Components that selectively transmit or block certain wavelengths of light, used in photography, scientific instruments, and communication systems.
• Scanner Mirrors: Critical in laser scanning systems, these mirrors require precise curvature and surface quality to ensure accurate light reflection and scanning performance.
• Endoscopic Components: High-precision optical elements used in medical devices for internal imaging and surgery, requiring exceptional clarity and durability.

In conclusion, precision optical machining and the materials used in these processes are essential for developing high-quality optical precision components. Manufacturers must adhere to strict standards and regulations to meet the demands of various industries, ensuring the highest level of performance and reliability in their optical components. As technology continues to advance, the collaboration between optical precision components manufacturers and their machining suppliers will lead to even more innovative and groundbreaking developments in the field.