JPH0612368B2 - Optical axis adjustment device for laser light and optical fiber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a technique for efficiently transmitting a laser beam through an optical fiber, and particularly to a laser for transmitting a high-power laser beam for processing through the optical fiber. The present invention relates to a device for adjusting the optical axes of light and an optical fiber.

[Conventional technology]

Conventionally, as an optical axis adjusting device for laser light of an optical fiber,
There is one as shown in FIG. The laser light 32 emitted from the laser device 31 is focused on one end of an optical fiber 34 for transmission by a laser incidence lens 33. The fine adjustment mechanism 35 is for aligning the optical axis of the optical fiber 34 with the optical axis of the laser light 32. The other end of the optical fiber 34 is connected to the emitting optical section 37 having a lens 36 used as an optical material.

The laser light 38 from the optical fiber 34 is emitted from the emission optical unit 3
The emitted light is directly received by an optical sensor (or optical power meter) 39, and its output is output from the amplifier 4
After being amplified by 1, it is displayed on the display unit 42, and by an operator manually operated by a worker or a numerically controlled adjusting unit drive device,
The optical axis of the laser light was adjusted so that the maximum output could be obtained.

[Problems to be solved by the invention]

In the above-mentioned conventional technique, as shown in FIG.
At the time of maintenance / inspection after setting the optical axis adjusting device, remove the optical fiber 34 from the system and install it so as to be coaxial with the optical sensor (or optical power meter) 39 and inspect the optical fiber 34. Alternatively, it is necessary to inspect by inserting the optical sensor 39 between the optical fiber 34 and the lens 36 as shown in FIG. 8 (a) or on the exit side of the lens 36 as shown in FIG. 8 (b). Therefore, there is a drawback that it requires a lot of time for maintenance and inspection.

Especially, in the adjustment and maintenance inspection work for the transmission of the high power laser for processing by the optical fiber, the small optical sensor cannot be used, and it is necessary to install the large optical power meter in consideration of heat radiation. There was a drawback that it took a lot of time for maintenance and inspection.

An object of the present invention is to provide an optical axis adjusting device for a laser beam and an optical fiber, which saves time required for maintenance and inspection and improves system reliability.

[Means for solving problems]

The optical axis adjusting device for laser light and optical fiber of the present invention is incorporated in a laser system. The emitted light of the laser light from the optical fiber that transmitted the laser light is reflected by the optical part of the system, and a part of this reflected light is received by the optical sensor that is not coaxial with the optical axis of the optical fiber. Then
In addition, it is displayed on the display device, and the laser beam oscillated from the laser device and the optical axis of the optical fiber are adjusted by this display value.

Since the optical axis adjusting device for the laser light and the optical fiber of the present invention is always incorporated in the system, it is not necessary to install an optical sensor (or optical power meter) during maintenance and inspection.
Further, since the installation position of the optical sensor is arranged at a position different from the optical axis of the optical fiber, the output value of the optical sensor when the optical fiber is adjusted to the position where the laser light transmits the maximum output is It is characterized by being an inflection point in the vicinity of the maximum output position instead of the maximum output position of the output value of.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of an optical axis adjusting device for a laser beam and an optical fiber showing an embodiment of the present invention. The laser light 2 oscillated from the laser device 1 is incident on the optical fiber 4 by the laser incidence lens 3 adjusted in advance. At this time, the transmission optical fiber 4 is held by the fine adjustment mechanism 5 for adjusting the optical axes of the laser light 2 and the laser incidence lens 3. The laser device 1 is composed of a laser device for processing with an output of 1 W or more, and a high-power laser beam 2 is emitted from the laser device 1.

The laser light 6 transmitted by the optical fiber 4 is an optical material (hereinafter referred to as a lens) 8 provided inside the emission optical section 7.
Is reflected by the surface of. The reflected light of the laser light 6 is received by the optical sensor 9 arranged inside the emitting optical unit 7 at a position not coaxial with the optical fiber 4. The light received by the optical sensor 9 is amplified by the amplifier 11, and its value is displayed on the display 1.
It is displayed in 2.

Here, in the conventional device shown in FIG. 5, when the laser light 38 emitted from the optical fiber 34 is received by an optical sensor 39 (or an optical power meter) mounted coaxially with the laser light 38. As shown in FIG. 6, the laser light output gradually decreases with the amount of deviation from the optical axis matching point of the optical fiber 4 in the fine adjustment mechanism 35. On the other hand, in the optical axis adjusting device of FIG. 1 according to the present invention, when part of the reflected light from the lens 8 of the laser light 6 emitted from the optical fiber 4 is received, the optical fiber in the fine adjustment mechanism 5 4 shows a waveform curve having a concave portion at the top as shown in FIG. 2 together with the amount of deviation from the optical axis coincidence point of No. 4.

This is because the emission angle 13 of the laser beam 6 from the optical fiber 4 shown in FIG. 4 is the smallest at the point where the optical axes of the laser beam 6 and the optical fiber 4 coincide with each other, and the emission angle changes as the optical axes deviate. This is because it becomes larger. The above-mentioned phenomenon is more remarkable in the graded index type optical fiber as compared with the step index type optical fiber, and is particularly effective for adjusting the optical axis of the graded index type optical fiber.

When the emission angle of the laser light 6 becomes large, the output of the optical sensor 9 that detects the laser light 6 not mounted coaxially with the optical fiber 4 increases. FIG. 2 shows the optical sensor output with respect to the amount of deviation from the optical axis coincidence point, and a concave portion having an inflection point A at the optical axis coincidence point B is formed at the top of the optical sensor output having a substantially convex shape. ing. Therefore, the second
After the optical fiber 4 is set at the position of the inflection point A shown in the figure, in the daily maintenance and inspection, the fine adjustment mechanism 5 is used to confirm that the output value of the optical sensor 9 is at the inflection point A of the output value. The optical axis of the laser beam and the optical fiber is adjusted by moving the lens to and checking.

FIG. 3 is a block diagram of an optical axis adjusting device for a laser beam and an optical fiber showing another embodiment of the present invention, and those having the same functions as those shown in FIG. Is omitted.

The light oscillated by the laser device 1 is transmitted by the optical fiber 4 in the same manner as the optical axis adjusting device of FIG. The emitted light is partially reflected by the lens surface of the lens 8, and a part of the reflected light is emitted by the emitting optical unit 1.
4 is transmitted by an optical fiber 15 for carrying reflected light, one end of which is arranged at an appropriate position, and is received by an optical sensor 16 and amplified by an amplifier 11, and then the output of the optical sensor 16 is displayed on a display 12.

In the embodiment shown in FIG. 3, since the emitting optical section 14 and the optical sensor 16 can be separated from each other by interposing the optical fiber 15, the inside of the emitting optical section 14 is transmitted during the transmission of the high-power laser light. It is possible to prevent the temperature drift of the sensitivity of the optical fiber 15 due to the rise of the temperature of the emitting optical unit 14 due to the loss of the laser light 6.

〔The invention's effect〕

As described above, according to the present invention, a part of the reflected light from the optical material of the laser light emitted from the optical fiber is received by the optical sensor that is not coaxial with the optical axis of the optical fiber. As a result, it is possible to provide an inexpensive and always usable laser beam and optical fiber optical axis adjustment device, which saves time required for maintenance and inspection, improves system reliability, and increases the laser power of a high-power laser device. In optical transmission, it has the effect of increasing the safety.

[Brief description of drawings]

FIG. 1 is a front view of an optical axis adjusting device for laser light and an optical fiber showing an embodiment of the present invention, FIG. 2 is a change diagram of an optical sensor output at the time of adjusting the optical axis in the device of FIG. 1, and FIG. FIG. 4 is a front view of an optical axis adjusting device for laser light and an optical fiber showing another embodiment of the present invention, FIG. 4 is a side view showing an emission angle of laser light emitted from the optical fiber, and FIG. FIG. 6 is a front view showing an example of an optical axis adjusting device for laser light and an optical fiber, FIG. 6 is a change diagram of an optical sensor output at the time of adjusting the optical axis in the device shown in FIG. 5, and FIGS. It is a front view which shows the example of arrangement | positioning of the optical sensor (optical power meter) at the time of an axis, respectively. 1 ... Laser device, 2 ... Laser light, 3 ... Laser entrance lens, 4 ... Transmission optical fiber, 5 ... Fine adjustment mechanism, 6 ... Laser light 7 ... Exiting optical section, 8 ... ... Lens, 9 ... Optical sensor, 12 ... Display device, 13 ... Laser light emitting angle, 14 ... Emitting optical section, 15 ... Reflected light carrying optical fiber, 16 ... Optical sensor.

Claims (3)

[Claims] 1. An optical fiber which emits a laser beam emitted from a laser light source from one end thereof, and a reflected light which is reflected from the incident surface of the laser beam emitted from the other end of the optical fiber and incident on an optical material in an optical section. A part of the detection means for detecting the intensity of the laser light taken in at a position which is not coaxial with the optical axis of the optical fiber in the optical part, a display means for displaying the detection result of the detection means, and an incident end of the optical fiber. And an optical axis adjusting means for adjusting the incident position of the laser light so as to match the inflection point of the intensity of the laser light from the display of the display means by moving the optical axis. Optical axis adjustment device for light and optical fiber. 2. The detecting means is an optical sensor for directly receiving reflected light in an optical section at a position which is not coaxial with the optical axis of the optical fiber to detect the intensity of the laser light. An optical axis adjusting device for a laser beam and an optical fiber according to the first aspect. 3. The detecting means takes in a part of the emitted light of the laser light by an optical fiber different from the optical fiber, and reflects the reflected light transmitted by the optical fiber to a position outside the optical section at its end. Claim 1 wherein the optical sensor arranged in the section detects the intensity of the laser light by receiving the light.
An optical axis adjusting device for the laser light and the optical fiber according to the item.