Cylinder CGH - What Is It and How It Works

A diffractive optical device called a cylinder CGH (computer-generated hologram) transforms a collimated interferometer wavefront into a converging cylindrical wavefront. Using the same CGH, a confocal null test can measure a variety of concave and convex cylindrical optics. Users can place convex cylindrical optics in the converging wavefront and concave cylindrical optics in the diverging wavefront.

Image Credit: AOM - Arizona Optical Metrology LLC

Technical Details

Image Credit: AOM - Arizona Optical Metrology LLC

• Requires a collimated input beam from the interferometer
• The null pattern is square or circular, depending on the size format
• Retro pattern enables simple alignment with interferometer
• 633 nm operating wavelength
• Antireflection coated back surface for rejection of unwanted reflections
• The AOM 6 degree-of-freedom alignment stages are interfaced with a mechanical cell that has mounting balls made of stainless steel

Compatible Products

Standard cylinder CGHs are installed in mechanical cells that interface directly with the AOM FP3 and FP6 fine alignment stages.

Arizona Optical Metrology Has a Cylinder CGH For Everyone

To accommodate the user's needs, computer-generated holograms are offered in a variety of sizes and focal lengths.

Image Credit: AOM - Arizona Optical Metrology LLC

2-Inch Cylinder CGHs

Minimal and reasonably priced for metrology of tiny cylindrical optics off the shelf and ready to ship.

• Substrate Size: 2” × 2” × 0.25”
• Null Pattern Size: 38 mm
• Null Pattern Shape: Square
• Cell size: 3-inch (C3 cell)

Source: AOM - Arizona Optical Metrology LLC

3-Inch Cylinder CGHs

Standard computer-generated holograms readily available for purchase are ideal for use with commercial interferometers with a standard 4-inch collimated output.

• Substrate Size: 3” × 3” × 0.25”
• Null Pattern Size: 60 mm
• Null Pattern Shape: Square
• Cell size: 3-inch (C3 cell)

Source: AOM - Arizona Optical Metrology LLC

A variety of standard 3-inch cylinder holograms are now available in the AOM Cylinder CGH Kit! It features five cylinder CGHs, covering a range from f/0.7 to f/6.0, ensuring comprehensive coverage for various cylinder UUTs. With the inclusion of two stages, a sample optic and part holder fixture, and quarter-inch magnetic mounting balls, the kit is a complete metrology system enabling you to quickly start measuring cylinder optics today.

4-Inch Cylinder CGHs

Best suited for conventional 4-inch collimated output commercial interferometers. Available by custom order.

• Substrate Size: 6” × 6” × 0.25”
• Null Pattern Size: 95 mm
• Null Pattern Shape: Circular
• Cell size: 6-inch (C6 cell)

Source: AOM - Arizona Optical Metrology LLC

6-Inch Cylinder CGHs

Greater coverage due to larger size; 6-inch collimated interferometer input required. Available by custom order.

• Substrate Size: 6” × 6” × 0.25”
• Null Pattern Size: 140 mm
• Null Pattern Shape: Circular
• Cell size: 6-inch (C6 cell)

Source: AOM - Arizona Optical Metrology LLC