| 摘要 |
A heterodyne distance-measuring interferometer having at least two diode lasers is described, the frequencies of which are mixed and caused to interfere by an integrated optical circuit. As a result, beat frequencies of different magnitude or a variable beat frequency can be generated by interference modulation. The fundamental or initial frequency is coupled out separately into an interferometric measuring section which extends in the ambient air and is stable, e.g. coupling into an air-Fabry-Pérot interferometer with a constant mirror separation (spacing). It is possible in this way to stabilise the wavelength, so that the fundamental frequency is connected to a defined length. After the interferometric mixing, the intensity of this radiation is divided and guided, on the one hand, onto a reference detector and, on the other hand, via the measuring section onto a measurement detector, the two of which are connected to one another in such a way that it is possible to measure their phase angle relative to one another and to the initial position of the instrument. Owing to this design, two frequencies can be mixed and modulated by interference in a simple way. An optical distance meter of high accuracy can be implemented in this way.
|
