How to manufacture high-precision dispersion prisms

Technical Description of Manufacturing Process for High-precision Dispersive Prisms

Dispersive prisms, as core optical components in fields such as spectral analysis and laser tuning, are manufactured around three core links: material selection, ultra-precision processing, and precise detection. The uniformity of refractive index, angular accuracy, and surface quality are strictly controlled to achieve efficient dispersion and precise deflection of light. Here are the complete manufacturing process and key technical points:

Ⅰ. Core manufacturing process

1. Material selection and pre-treatment

The base  material is preferred to be optical glass (such as high dispersion flint  glass, medium dispersion crown glass), fused quartz or calcium fluoride crystals, which should meet the requirements of high transmittance and  stable dispersion in the target band.

The raw  materials are screened by ultrasonic testing to remove internal bubbles, impurities and stress defects; The internal stress of the material is eliminated through high-temperature annealing (300-500 ° C, holding for      8-12 hours) to ensure optical uniformity.

2. Blank forming and rough machining

Using diamond wire cutting technology, the pre-treated material is cut into prism blanks close to the size of the finished product, with dimensional tolerances controlled within ±0.2mm.

In the rough  grinding stage, diamond grinding wheels are used to remove the cutting marks through graded grinding to initially form the prism top Angle and refraction surface, with surface shape accuracy controlled at λ/2 (λ=632.8nm),  laying the foundation for fine grinding.

3 Ultra-precision fine grinding and polishing

Fine grinding uses fine-grained diamond grinding paste to gradually optimize surface flatness, with surface roughness Ra≤0.02μm and top Angle error reduced to within ±5 ".

The polishing  process uses nano-scale cerium oxide polishing powder, combined with chemical mechanical polishing (CMP) or ion beam polishing (IBF) techniques, to reduce the surface roughness to less than 0.1nm and achieve   surface shape accuracy of λ/20.

The polishing   process is carried out in a Class 100 cleanroom to avoid dust   contamination affecting the surface quality

4 Coating optimization (optional)

For specific  application scenarios, anti-reflection coatings are applied to the  refracting surface of the prism to reduce reflection loss in the target      band and increase transmittance to over 99%.

After coating,  high-temperature baking (150-200 ° C for 2 hours)  is carried out to enhance the adhesion of the coating and ensure stability      in harsh environments.

5. Precision detection and calibration

Angle accuracy  testing: Using a spectrophotometer and a precision goniometer, measure the      top Angle and deflection Angle using the "double parallel fine-tuning method" to ensure that the top Angle tolerance is ≤±2 "to meet  the dispersion accuracy requirements.

Surface quality  inspection: In accordance with ISO 10110-7 standard, surface scratches (≤20/10 standard)   and pitting are inspected by high-power microscope, no obvious defects  ISO.

Optical  performance testing: Wavefront distortion was detected using a laser  interferometer, and transmittance and dispersion at different wavelengths  were verified using a UV-visible spectrophotometer to ensure compliance  with design specifications.

6. Cleaning and packaging

Use a combination of ultrasonic cleaning and anhydrous ethanol wiping to  thoroughly remove residual polishing powder and oil stains on the surface.

The cleaned  prisms are dried and vacuum-packed with anti-static cushioning material to prevent damage during transportation.

7. Key quality control standards

Optical  specifications: Target band transmittance ≥98%, dispersion  rate error ≤±1%, refractive index uniformity deviation ≤1×10⁻⁶.

Geometric accuracy: Top Angle tolerance ≤±2 ",  surface shape accuracy ≤λ/20, surface roughness Ra≤0.1nm.

Surface quality:  Compliant with ISO 10110-7 standard, no scratches, pitting or edge  chipping beyond the specified limits ISO.

8. Description of application scenarios

In the field of spectral analysis, Amisi prisms with a combination of flint glass and  crown glass are preferred to enhance dispersion and be compatible with equipment such as spectrophotometers.

Laser tuning  field: Using fused silica material combined with ion beam polishing technology to enhance the laser damage resistance threshold to meet the requirements of high-power laser systems.

Ultraviolet band  application: Use calcium fluoride crystal material to ensure high transmittance in the ultraviolet region, compatible with deep ultraviolet spectroscopy detection equipment.

UltraOpto, with its advanced ultra-precision processing equipment and strict quality control system, can customize high-precision dispersive prisms of different materials and specifications according to customer requirements, providing reliable core component support for fields such as spectroscopy, laser technology, and optical inspection. For custom solutions, feel free to contact the technical support team.

Key technical Parameter comparison Table of High-precision Dispersion Prism