Abstract
This paper describes two common path heterodyne interferometer systems. In each case the two arms of the interferometer traverse a very similar path so that the deleterious effects of microphonics cancel out. The first system is differential in that the relative phase between two displaced spots of similar dimensions are compared. The novel feature of this system is that in addition to obtaining the phase difference between the spots the differential of the intensity reflection coefficient can also be obtained by modulating the power in each of the spots. The second system is an absolute interferometer where the phase between two spots of very dissimilar sizes is obtained. The large spot thus measures the average sample phase whilst the tightly focused beam measures the local phase variation. By using an additional reference beam one can ensure that the two beams of dissimilar profiles interfere effectively. Results from each of the systems are presented.
| Original language | English |
|---|---|
| Pages (from-to) | 121-125 |
| Number of pages | 5 |
| Journal | Materials Science and Engineering A |
| Volume | 122 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 10 Dec 1989 |
| Externally published | Yes |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering