JPS5941883A - Ring laser gyro - Google Patents

Abstract

PURPOSE:To obtain a ring laser gyro, which has no degradation in reliability due to the problem of coupling for taking out an output and is suitable for mass production, by forming specific ring lasers, an output waveguide, a light detector, and a nonreflecting terminal in the same substrate. CONSTITUTION:Y branches 11a and 12a having directivity are provided in ring lasers 11 and 12 so that they are oscillated only in the reverse direction each other. They are not oscillated to the other directions since propagation loss is large. The ring laser 11 is oscillated only in the clockwise direction, and the ring laser 12 is oscillated only in the counterclockwise direction. An output waveguide 13, which forms a directional coupler that is coupled to both ring lasers 11 and 12, is provided between the two ring lasers 11 and 12. The parts of the outputs of the ring lasers 11 and 12 are taken out and synthesized, and the result is guided to a light detector 15. At the other end of the output waveguide 13, a nonreflecting terminal 14, which absorbs the reflection from the light detector 15 and natural emitted light from the ring lasers 11 and 12, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to an optical gyroscope for detecting angular velocity, and more particularly to a small ring formed within the same substrate with an integrated optical coupling part. It concerns a laser gyro.

(2) Prior art and problems The conventional laser gyro has a discharge part 1 as shown in Fig. 1(a).
A laser gyro consisting of a sharp 2 and a sharp 2 is arranged in a ring shape as shown in Fig. 2(b), and the laser beam propagates in opposite directions clockwise and counterclockwise inside the laser gyro arranged in the ring shape. I was extracting the beat signal. To output clockwise and counterclockwise outputs to the outside, the clockwise and counterclockwise lights transmitted through mirror 2a are reflected by mirrors 2d and 2e, as shown in FIG.
-2f, the light was directed in the same direction. Generally, such a ring laser diode has an X shape as shown in FIG.

It was placed on the y and z axes and was used to detect the angular velocity of an object. However, such a ring laser gyro has a drawback that when the angular velocity becomes small, the oscillation light in the clockwise direction "-'-↓" and the counterclockwise direction causes locking and no beat signal is generated. Furthermore, the structure Jh in which the optical coupling portion is taken out to the outside as shown in FIG. 2 has the disadvantage that it is mechanically weak and it is difficult to obtain a highly reliable structure.

On the other hand, as shown in FIG. 4 (IL), there are active substance lasers that use an active substance*6 and ring lasers that use a ring-shaped laser 7 and extract the output to the outside using an output waveguide 8. However, in order to configure this as a ring-shaped laser gyro, there were problems in the structure for extracting the output to the outside.

(3) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides a ring rate gyro that does not take the output to the outside, prevents deterioration in reliability due to coupling problems, and is suitable for rough production and can be co-supplied at low cost. The purpose is to

(4) Structure of the Invention According to the present invention, the object is to provide two ring lasers with equal diameters having gains in opposite directions and an output waveguide distributively coupled to the two ring lasers in the same substrate. , a ring laser gyro comprising: a photodetector provided at an end of the output waveguide in the output light direction of the ring laser; and a non-reflection termination provided at the other end of the output waveguide. This is achieved by insulting the

(5) Embodiments of the Invention Hereinafter, embodiments of the ring laser gyro according to the present invention will be described in detail with reference to the drawings.

FIG. 5 shows an embodiment of the present invention, in which 10 is a substrate, 11 and 12 are ring lasers, 13 is an output waveguide, 14 is a non-reflective termination, 15 is a photodetector, and 15 is a ring laser. Directional coupling is performed between the lasers 11, 12 and the output waveguide.

In FIG. 5, the ring lasers 11 and 12 are directional Y-branched lta, i, so that they oscillate only in opposite directions.
Since za is attached, oscillation does not occur in the opposite direction because the propagation loss is large. Tsuma Schillingrede 11 is clockwise, 12
oscillates only in the counterclockwise direction. There is an output waveguide 13 between these two Ringlades 11 and 12 that is coupled to both to form a directional coupler, which extracts a part of the output of the Ringlades 11 and 12 and combines them for optical detection. vessel 15
lead to. In addition, the output waveguide 13 (lp other end is the photodetector 1
A non-reflection termination 14 is provided to absorb reflection from the ring laser 5 and spontaneous emission from the ring laser fla+11b.

FIG. 6 shows another embodiment of the invention. In the embodiment shown in FIG. 5, a Y branch is provided to give directionality to the oscillation of the ring laser, but in FIG. 6, the difference in width Kl of the waveguide of the ring laser is 111L'.

12 A' is added. It goes without saying that similarly, the step may be provided in the thickness direction instead of in the width direction. In the m6 diagram, Ringrader ll & clockwise,
12m, of course, oscillates counterclockwise.

FIG. 7 shows yet another embodiment of the invention. In FIGS. 5 and 6, the ring lasers both excite the entire area, and therefore, when it is necessary to increase the area of the ring laser, a large current is required. For this reason, in Fig. 7, the excitation regions are limited to 16 and 17, and excitation is performed in these regions, while the other regions are simply used as passive waveguides), thereby reducing the diameter of the ring. Can be made larger.

(6) Effects of the Invention As explained in detail above, the present invention is configured so that lights rotating in opposite directions are combined in one waveguide within the same substrate and a beat is obtained by a photodetector. , it is possible to construct a compact Lingle de gyro on the same substrate without having an external light coupling part, and to create a highly reliable and inexpensive device that does not cause the locking phenomenon of light in both directions. The effects of the present invention are remarkable.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of a conventional RADE and ring laser gyro, Fig. 2 is a structural diagram of the external extraction part of the ring laser gyro in Fig. 1, and Fig. 3 is a diagram of the ring laser gyro in Fig. 1. 3-dimensional layout r#, Figure 4 is a diagram showing an example of a conventional semiconductor radar, Figure 5 is a diagram showing an example of a Ring Rader gyro according to the present invention, and Figure 6 is a diagram showing an example of a semiconductor radar according to the present invention. FIG. 7 is a diagram showing still another embodiment of the present invention. In the drawing, 10 is a substrate, 1lpHa, llb. 12 p l 2 a y l 2 b is a ring laser, 13kJ, output waveguide, 14 is a non-reflection termination, 15t
rJ, photodetector, 16.17 indicate the excitation region, respectively. Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 393-

Claims (1)

[Claims] In the same substrate, two ring lasers having equal diameters and having gains in opposite directions, an output waveguide that is distributed and coupled to the two ring lasers, and an output light direction of the ring laser in the output waveguide. A ring laser gyro, comprising: a photodetector provided at one end of the output waveguide; and a non-reflection termination provided at the other end of the output waveguide.