Waveguide type displacement interferometer having two reference

Details Waveguide type displacement interferometer having two reference Waveguide type displacement interferometer having two reference

1992-09-21

1995-03-07

Turner, Samuel A.

Optics: measuring and testing

By dispersed light spectroscopy

Utilizing a spectrometer

385 12, G01B 902

Patent

active

053963288

DESCRIPTION:

BRIEF SUMMARY
The invention relates to an interferometer according to the preamble of the claim as well as a method for determining correct as to signs, the change in the optical path length with the aid of said interferometer.
A Michelson interferometer which is built in the manner of integrated optics is described in German disclosure letter 38 25 606. The interferometer consists of a monochromatic laser light source, a beam splitting means, a reference mirror and a measuring mirror as well as light guide fibers for guiding the light to the beam splitting means and for guiding the light carrying the measurement signal back to a detector. Therein, the beam splitting means is formed by an integrated-optical, symmetrical coupling capacitor in a glass substrate in which wave guides produced by struturated ion exchange are arranged, which on one hand form the measuring arm and on the other hand the reference arm of the interferometer.
The invention, therefore, is based on the object of giving an interferometer of the kind cited in the beginning, such a design that it is capable of proving optical path lengths changes with high resolution and determined as to direction in a simple and reliable manner.
The invention solves said object with the aid of the features of the characterizing clause of claim 1. Advantageous embodiments of the invention are subject of the subclaims. Furthermore, a method is stated which, with the aid of the interferometer according to the present invention, renders possible the measurement of optical path lengths changes determined as to direction and with great accuracy.
With the aid of the interferometer according to the present invention and the method according to the present invention, respectively, it is, thus, possible to carry out high-resolution position measurements as well as to determine changes in the refractive index. By the combination of counting methods and single-sideband modulation, therefore, also large path distance changes can be quickly displayed in a manner determined as to directions (counting method) and the exact value of the optical path distance change or the change in refractive index, respectively, can be recognized (single-sideband method).
Embodiments of the invention now are described with reference to the attached drawings. Therein:
FIG. 1 shows the schematical construction of an integrated optics Michelson interferometer;
FIG. 2 shows the switching plan of evaluation electronics;
FIG. 3 shows a variation of a Michelson interferometer with direct illumination;
FIG. 4 shows a variation of a Michelson interferometer with passive phase modulator;
FIG. 5 shows a Michelson interferometer with Bragg reflectors;
FIG. 6 shows an interferometor as gas sensor;
FIG. 7 shows a Michelson interferometer with decoupling gate in side view;
FIG. 8 shows a Michelson interferometer with decoupling gate in top view;
FIG. 9 shows a refractometer in side view;
FIG. 10 shows a refractometer in top view;
FIG. 11 shows a double Mach-Zehnder interferomter as sensor;
FIG. 12 shows a double Mach-Zehnder interferometer for distance measurement in side view;
FIG. 13 shows a double Mach-Zehnder interferometer for distance measurement in top view.
In the following at first quite in general, an embodiment of a Michelson interferometer according to the present invention is described. In the interferometer, serveral beam splitting means are provided for in the glass substrate so that one common arm as measuring arm and two arms as reference arms will result. In the common arm for example the light of a helium-neon laser is coupled in through a wave guide, preferably a glass fiber. Subsequent to the coupling-in point the measuring arm separates into two wave guide structures running in the same direction as the reference arms and which are guided to meet again in the further course. Thus, two Y-shaped branchings are formed, in which the light is first separated and then combined, respectively. Thus, two direction couplers (3 dB) are formed which serve as beam splitting means. The reflected light from

REFERENCES:
patent: 4661964 (1987-04-01), Haavisto
patent: 4744661 (1988-05-01), Ulbers et al.
patent: 4759627 (1988-07-01), Thylen et al.
patent: 4865453 (1989-09-01), Gidon et al.
patent: 4909629 (1990-03-01), Yokokura et al.
patent: 4941744 (1990-07-01), Yokokura et al.
patent: 5187545 (1993-01-01), Allgauer

Affiliated with

Also associated with

Rating

Waveguide type displacement interferometer having two reference does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Waveguide type displacement interferometer having two reference , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Waveguide type displacement interferometer having two reference will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1410435