How is a semi-pentagonal prism processed and manufactured?

The manufacturing process of semi-pentaprisms (Technical description)

The UltraOpto semi-pentaprism is made with a highly uniform optical substrate and ultra-precision process, with a core 45° no deflection of the beam, and the key angles and surface shape accuracy are fully controllable. It is suitable for high-end scenarios such as machine vision, laser measurement, and precision inspection. The following is the standardized manufacturing process and quality control system, which precisely guarantees the stability of the product's optical performance.

Ⅰ. Core Manufacturing Processes (9 Key Processes)

1. Substrate selection and pre-treatment

Material selection: Match the substrate according to the application band - use BK7 Grade A for visible light scenarios and fused quartz (such as 7980) for infrared/high power laser scenarios to ensure low dispersion and high transmittance;

Raw material inspection: 

Check the glass uniformity by interferometer, verify the transmittance by spectrophotometer, eliminate defects such as bubbles and streaks to ensure the quality of the base material;

Blank cutting: Use a diamond wire saw to cut the glass blocks into blanks close to the size of the finished product, with the size allowance controlled at 0.5-1.0mm to reduce subsequent processing loss.

2. Precise positioning of the upper plate (clamping core)

Use the varnish mounting method (suitable for small and medium size batch processing), with a cast iron mold body that matches the Angle, preheat to 60-80 ° C, and then fix the blank on the inclined surface of the mold body with a varnish mixture; For high-precision parts, the glue-free contact method (van der Waals force bonding) is used to avoid the impact of adhesive layer stress on Angle accuracy, with clamping deviation ≤0.001mm/m.

3.Roughing of the profile (forming base)

Use a diamond grinding wheel to roughly grind the semi-pentaprism geometry profile, giving priority to machining the reference shapes and positions of the 45° reflective surface, incident surface, and emergent surface; Remove most of the allowance to form a shape close to the finished product, with surface roughness controlled below Ra 1.6μm to lay the foundation for fine grinding.

4.Angle finishing (precision is key)

With the reference plane as the positioning, use resin-bonded grinding wheels to finely grind each functional surface, with the core controlling the 45° deflection Angle and perpendicularity to the reflective surface; After fine grinding, the Angle tolerance is ≤±3 ", the surface shape accuracy is λ/[email protected], the surface is uniform frosted glass, and there are no deep scratches.

5.Ultra-precision polishing (surface core)

Polishing with a polyurethane polishing mold, combined with cerium oxide polishing liquid, in a constant temperature (20±0.5 ° C), constant humidity environment; High transmittance polishing is performed on the incident/emergent surfaces and high flatness polishing on the reflective surfaces, ultimately achieving a surface quality of 20-10 (scratches/pitting) and surface shape accuracy λ/[email protected] (λ/20 for high-precision custom parts).

6.Chamfering and edge strengthening

Use diamond chamfering wheels to chamfer all sharp edges by 0.2-0.5mm to prevent chipping and chipping. In high-power scenarios, add edge enhancement to improve resistance to laser damage and avoid edge scattering affecting the optical path.

7.Vacuum coating (Feature customization)

Reflective surface: Metal + dielectric composite film (such as aluminum film + indium oxide protection), visible light band reflectance R > 95%, with black lacquer sealing to prevent environmental erosion;

Incident/exit: Custom anti-reflection coating (AR), target band transmittance T > 99%, reduced light loss;

Non-optical surface: Spray matte black paint to suppress stray light and improve system signal-to-noise ratio.

8.Precision cutting and separation (batch process)

After the long strip billet is processed on the plate, the cutting and arc processing are carried out simultaneously with the combined tool (suitable for batch production); After separation, ultrasonic cleaning is used to remove paint residue and polishing dust to ensure the optical surface is clean.

9.Final inspection and packaging out of the warehouse

After passing the full-dimensional inspection, they are independently packaged in anti-static and scratch-resistant packaging materials in a Class 100 cleanroom, with inspection reports attached to ensure no damage during transportation.

Ⅱ. Key quality control nodes and UltraOpto precision standards

Ⅲ. Process characteristics and application fit

Precision is controllable:

 From rough grinding to final inspection, the entire process is managed in a closed loop withmetrology-grade equipment, and the precision of key angles and surface shapes far exceeds the industry standard;

Strong customization: 

Customizable base material (BK7 / fused quartz/sapphire), size (2.5×2.5-100×100mm), coating scheme according to customer requirements, suitable for different scenarios;

High stability: 

Glue-free clamping and vacuum coating process effectively avoid stress deformation and environmental erosion, ensuring stable performance of prisms for long-term use.

UltraOpto semi-pentaprisms, with strict process control and customization capabilities, provide highly reliable optical core components for machine vision, lidar, precision inspection and other fields, helping customers' systems achieve precise optical path control.