HA50 Series Alignment CGHs
Our HA50 series Alignment CGHs are used to optically align CGHs to your interferometer test beam and radius slide axis. On replacing the Alignment CGH with a Custom CGH Null, the spherical or collimated test beam is diffracted to produce a prescribed aspheric wavefront.
Tilt or Decenter?
For off-axis CGHs, one must choose between tilting or decentering. Tilting leaves the CGH centered in the field of view, but results in a test axis which is not parallel to the interferometer axis. Decentering keeps the test axis parallel to the interferometer (and radius slide) axis, but may require a faster transmission sphere to fill the decentered test pupil.
Five Models Available
We offer four standard HA50 Series Alignment CGHs for use with our small frame CGH Nulls and your 633 nm wavelength interferometer. Our popular Model HA50D0 provides 12 on-axis foci and is sufficient for most users. Models HA50D1 and HA50D3 offer the same focal distances, but with 1 and 3 mm decenter between interferometer and CGH axes. Model HA50T1 offers 1 degree tilt (or equivalent decenter) between interferometer and CGH axes.
Specifications
The table below gives CGH coordinates (x,y,z) of the several transmission sphere focus locations. Grating patterns are “spherical” to about 1 fringe. Diffraction efficiency is approximately 1 percent in 3rd order.
| HA50 Series Alignment CGHs | ||||||||
|---|---|---|---|---|---|---|---|---|
| Model | Focal Distances (mm) | Price | ||||||
| Z= | ±20 | ±33 | ±55 | ±90 | ±150 | ±250 | ||
| HA50D0 | X= Y= |
0.000 0.000 |
0.000 0.000 |
0.000 0.000 |
0.000 0.000 |
0.000 0.000 |
0.000 0.000 |
Pricing |
| HA50D1 | X= Y= |
0.000 -1.000 |
0.000 -1.000 |
0.000 -1.000 |
0.000 -1.000 |
0.000 -1.000 |
0.000 -1.000 |
Inquire |
| HA50D3 | X= Y= |
0.000 -3.000 |
0.000 -3.000 |
0.000 -3.000 |
0.000 -3.000 |
0.000 -3.000 |
0.000 -3.000 |
Inquire |
| HA50T1 | X= Y= |
-0.349 0.000 |
-0.576 0.000 |
-0.960 0.000 |
-1.571 0.000 |
-2.618 0.000 |
-4.364 0.000 |
Inquire |
