Fabrication Process

Reserved optical glass and crystal raw materials are processed into blanks matching the required base dimensions via surface milling machines, wire saws, internal circular cutting machines, cylindrical grinders and other equipment. We can produce various blanks ranging from 3 mm to 500 mm in diameter, providing precise preforms for spherical lenses, cylindrical lenses, flat windows, prisms and other optical components.

Rough grinding is performed on pre-cut blanks to achieve the required surface roughness for subsequent processing and complete blocking and shaping. This process lays the foundation for precision polishing and relies heavily on skilled operators. Related equipment: grinding & polishing machines, 2-axis grinding & polishing machines, single spindle grinders, centering machines, etc.

Equipped with 8 precision engraving machines and 3 CNC machining centers, we conduct versatile custom processing on optical components, including crystal orientation cutting & positioning, drilling, grooving, edge cutting, square pocketing and other special-shaped machining operations, enabling the production of custom special cylindrical lenses. This process represents the core competitive advantage that distinguishes Benchu Optoelectronics from conventional optical manufacturers.

Based on rough grinding, fine abrasive grains are used for fine grinding to further improve surface uniformity and prepare the optimal surface condition for polishing. The polishing process determines the final surface quality, surface figure and center thickness of the lens, which is the most critical production step. Repeated polishing is carried out until all parameters meet drawing specifications before proceeding to the next process.

Benchu Optoelectronics is equipped with one domestic Nanguang 900mm coating machine and one Japanese Shincron 1500mm precision coating machine. Available coatings and products include anti-reflection coatings, various filters (bandpass, edge, long-pass), metallic reflective coatings (aluminum/silver/gold), beam splitters, dichroic mirrors, etc. Cleaning and anti-corrosion treatment are performed prior to coating to ensure excellent coating adhesion and weather resistance.

Every lens is inspected for surface figure parameters (PV/RMS) using US ZYGO laser interferometers and flat interferometers. Decentration, focal length and curvature are individually tested with the LensMT-DAFA dual-light path centration tester and LensFC-MT focal length meter. After passing full inspection, test reports are provided and delivered together with the products to customers.