The Twyman & Green Interferometer modified by the late Mr. D. O. Hendrix is for testing the quality of optical elements such as windows, wedges, prisms or plane mirrors in any combination. It employs parallel beams of light and it is the effect of the optical elements under test on these beams which is measured by the instrument. These beams are affected by the surface quality as well as the homogeneity of the glass.
Use of this Interferometer shows the sum of the errors contained in an element or in an entire assembly. These errors can then be corrected by re-working one or more surfaces to compensate for the total error. In other words, the Interferometer permits examination of an optical train as a whole and then correction of any of the surfaces just as if a simple system containing but one element were being corrected.
For more theory of operation, please refer to the Principles of Interferometry Application Note.
Detailed Specifications:
| System Accuracy | 1/20 wave length | |
| Aperture Diameter | 3" | |
| Base Dimensions | Width | 36" |
| Depth | 24" | |
| Thickness | 6" | |
| Mirror Adjustments | Fine pitch threads on both vertical and horizontal screws. | |
| Light Source | Helium Neon Laser at 6328 Å | |
| Standard Accessories | Auxiliary eyepiece
Polaroid film packet |
|
| Working Surface | Shock-mounted, black granite | |
| Overall Dimensions | Width | 40" |
| Depth | 24" | |
| Height | 53" | |
| Overall Weight | Approximately 750 pounds | |
Davidson Optronics, Inc.
Phone: (626) 962-5181
Fax: (626) 962-5188
E-mail: sales@davidsonoptronics.com