JPH01147882A - Laser device - Google Patents

Abstract

PURPOSE:To make the output of a higher harmonics constant, by a device wherein an invisible laser beam and a higher harmonics for a guide beam are optically separated to measure the output of the laser beam or the higher harmonics, and according to the measured value thereof, the output of the higher harmonics is controlled. CONSTITUTION:The invisible laser beam L1 emitted from a laser oscillator 1 is entered into a higher harmonics generating device 5 from which a visible laser beam L2 is emitted, and then on one hand through a first and second wavelength selective transparent mirror 6, 7 entered into a light guiding fiber 9. On the other hand, a part of the laser beam L2 is reflected by a mirror 6 and then incident on a transparent mirror 11. A part of the laser beam L2 passing through the transparent mirror 11 is entered into a power meter 12. A transmittance variable filter 13 is controlled by a driving device 15 so that when the detected value in the power meter 12 is large compared with the predetermined value, the transmittance variable filter 13 disposed in the optical path of the laser beam L2 is decreased in its transmittance, while when the detected value is small compared with the predetermined value, the filter 13 is increased in its transmittance. As a result, the laser beam L2 passing through the filter 13 is made to be constant in its output.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser device for treating, for example, a living body with invisible laser light.

[Prior Art] Nd:YAG laser is often used as a laser device for treatment of living organisms. Since the infrared laser light emitted from this type of laser device is invisible, treatment cannot be performed safely and reliably. Therefore, visible light is output coaxially with the invisible light, and this visible light is used as guide light. Generally, He--Ne laser light is used as the guide light. however,
He--Ne laser light is a red light with a wavelength of 838.2 na+, and when it is irradiated to tissues in body cavities or sub-epidermal areas, it is very difficult to see because it has a similar color.

Therefore, from the viewpoint of cost and visibility, it has been considered to use harmonics of infrared laser light as guide light. In that case, a harmonic generation device that generates harmonics in the visible range from the invisible laser light is provided in the optical path of the invisible laser light, thereby obtaining visible light.

[Problems to be Solved by the Invention] However, in a conventional laser device that uses harmonics as a guide light, the guide light, which is a harmonic wave, changes depending on the increase or decrease in the output of the invisible laser light emitted from this laser device. The output will also increase or decrease.

Therefore, when performing treatment using a high-output invisible laser beam, the brightness of the guide light is too high, and the area irradiated with the guide light becomes extremely pale.

This invention was made based on the above circumstances, and its purpose is to create a laser that can maintain the output of visible laser light almost constant regardless of the increase or decrease in the output of invisible laser light. The goal is to provide equipment.

[Means and operations for solving the problems] In order to solve the above problems, the present invention includes a laser oscillator that generates an invisible laser beam, and a laser oscillator that is installed in the optical path of the invisible laser beam to emit visible light from the invisible laser beam. a harmonic generator for generating harmonics; an optical means for separating the invisible laser beam from the harmonics; a measuring means for measuring the output of either the invisible laser beam or the harmonics; control means is provided in the optical path of and controls the output of the harmonics according to the measured value by the measurement means. Thereby, the output of the harmonic wave can be kept almost constant even if the output of the invisible laser beam varies.

[Embodiment 1] A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The laser device shown in FIG.
: Equipped with a laser oscillator 1, such as a YAG laser. This laser oscillator 1 has a laser rod 2 made of YAG crystal arranged between a total reflection mirror 3 and a partially transmission mirror 4, and an excitation lamp 5a arranged opposite to the laser rod 2. .

The wavelength emitted from the laser oscillator 1 is 11064n
The invisible laser light is input to the harmonic generator 5. As a result, harmonics, in this embodiment, green visible laser light L2 having a wavelength of 532 nm are generated from this harmonic generator 5.

The invisible laser beam L1 from the harmonic generator 5 is the first
The light passes through the wavelength-selective transmission mirror 6 and the second wavelength-selective transmission mirror 7, is focused by the condenser lens 8, and enters the light guide fiber 9. Further, the visible laser beam L2 generated by the harmonic generator 5 is reflected by the first wavelength-selective transmission mirror 6 and partially enters the transmission mirror 11. Visible laser beam L2 transmitted through this partially transmitting mirror 11
A part of the visible laser beam L enters the power meter 12 and its output is detected, and the visible laser beam L partially reflected by the above-mentioned transmission mirror 11 is detected.
2 is made to enter the variable transmittance filter 13. As shown in FIG. 2, this variable transmittance filter 13 has a disk shape, and has a number of stages with different transmittances, in this embodiment, six circular first to sixth filter sections 14a to 14.
4f are formed at equal intervals in the circumferential direction. The transmittance of the first filter section 14a is set to 0%, the transmittance of the second filter section 14b is set to 20%, and the transmittance of the third filter 14 is set to 0%.
f is set to 10096.

The variable transmittance filter 13 is attached at its center to the rotating shaft 16 of the drive device 15.
The rotation is controlled by 5.

The drive device 15 is adapted to be driven by a signal from the power meter 12. That is, when the output of the visible laser beam L2 that has passed through the partially transmitting mirror 11 detected by the power meter 12 is larger than a predetermined value, the visible laser beam L2 that has been reflected by the partially transmitting mirror 11 is detected by the power meter 12.
The variable transmittance filter 13 is rotationally controlled so that the filter section with low transmittance is positioned in the optical path No. 2, and conversely, when the output detected by the power meter 12 is small, the filter section with high transmittance is positioned. It has become. Therefore, the output of the visible laser light L2 that is partially reflected by the transmission mirror 11 and transmitted through the variable transmittance filter 13 is controlled to be almost constant at all times.

Visible laser light L transmitted through the variable transmittance filter 13
2 is reflected by the reflection mirror 17 and the second wavelength selective mirror 7 to align the optical axis with the invisible laser beam. Since the visible laser beam L2 is focused by the condenser lens 8 and enters the light guide fiber 9, it irradiates the same position as the invisible laser beam L1.

According to the laser device having such a configuration, the laser oscillator 1
When the output of the invisible laser beam L1 emitted from the harmonic generator 5 is large, the visible laser beam L2 emitted from the harmonic generator 5
The output of will also increase. As the output of the visible laser beam L2 increases, the output of the visible laser beam L2 that is reflected by the first wavelength-selective transmission mirror 6, partially transmits through the transmission mirror 11, and enters the power meter 12 also increases. When the drive device 15 receives the signal from the power meter 12, it rotates the variable transmittance filter 13 according to the magnitude of the visible laser beam L2, and drives the variable transmittance filter 13 to rotate the filter section with low transmittance, for example, the second filter section. 14b or the third filter section 14c is positioned on the optical path of the visible laser beam L2 reflected by the partially transmitting mirror 11. Therefore, the output of the visible laser beam L2 is lowered by the variable transmittance filter 13 and the brightness is also lowered, so that the irradiation area of the visible laser beam L2 that passes through the light guide fiber 9 and irradiates living tissues etc. is invisible. This will prevent you from becoming uncomfortable.

In addition, the invisible laser beam L oscillated from the laser oscillator 1
When the output of the visible laser beam L1 is small, the output of the visible laser beam L1 generated by the harmonic generator 5 is also small. Then, in response to a signal from the power meter 12 that has detected the output, the driving device 15 drives a filter section with a high transmittance of the variable transmittance filter 13, for example, the sixth filter section 14f, to generate a visible laser beam reflected by the partially transmitting mirror 11. It is located in the optical path of the light L2. Therefore, the visible laser beam L2 irradiates the living tissue and the like without reducing its brightness, so that the irradiated area can be clearly confirmed.

That is, according to the laser device having the above configuration, the visible laser beam L2 can be used to irradiate the irradiated area such as biological tissue with almost constant brightness at all times, so that the irradiated area can be confirmed well and reliably. can.

FIGS. 3 and 4 show second and third embodiments of the present invention, respectively, which are modified examples of the variable transmittance filter. In other words, the filter 13a shown in FIG. 3 has a transmittance that continuously changes along the circumferential direction indicated by the arrow, and such a filter 13a makes it easier to keep the output of the visible laser beam L2 constant. .

A filter 13b shown in FIG. 4 has a plurality of filter sections 14a to 14f having different transmittances formed in parallel, and this filter 13b is slid by a slide member 20, thereby allowing a filter section located in the optical path of the visible laser beam L2. made it possible to change.

FIG. 5 shows a fourth embodiment of the present invention, in which a partially transmitting mirror 11a is installed in the optical path of the invisible laser beam L1. The output of the invisible laser beam Ll reflected by the partially transmitting mirror 11a is detected by the power meter 12, and the drive device 15 is driven by the detection signal.

FIG. 6 shows a fifth embodiment of the invention. This embodiment has the structure of the first embodiment shown in FIG. 1, but a variable transmittance filter 21 is provided in the optical path of the invisible laser beam. The transmittance of this variable transmittance filter 21 is as follows: visible laser light L
It is controlled via a filter control section 22 by a signal from a power meter 12 that detects the output of the power meter 2. The variable transmittance filter 21 is preferably one that transmits a portion of the invisible laser beam L1 and absorbs the remainder, but it may also be one that transmits a portion of the invisible laser beam L1 and reflects the remainder as shown in the figure. In that case, the reflected invisible laser beam L1 is received by the heat-resistant member 23.

Further, if the optical path of the invisible laser beam L1 is shifted by the variable transmittance filter 21, the correction plate 24 is used to correct it. Furthermore, a power supply control section 25 that controls the excitation power of the laser oscillator 1 is connected to the filter control section 2.
2, it is controlled by a signal from the power meter 12.

Then, the visible laser beam L2 detected by the power meter 12
If the output of the invisible laser beam L1 is to be further reduced and used after the output of the invisible laser beam L1 becomes below a certain value, the output signal of the visible laser beam L2 detected by the power meter 12 is sent to the power supply control unit 25, and then The excitation power of the laser oscillator 1 is prevented from lowering any further, and the transmittance of the variable transmittance filter 21 is lowered accordingly by the filter control unit 22 which receives the signal from the power meter 12. The output of the invisible laser beam L1 is reduced.

In other words, even when a treatment or other treatment is performed using the low-power invisible laser light L1, the output of the visible laser light L2 will not fall below a predetermined value, so the visible laser light L2 can be set to the optimal brightness. .

〔Effect of the invention〕

As described above, in the case of generating harmonic visible laser light from invisible laser light using a harmonic generator, the present invention measures the output of one of these laser lights,
The output of the visible laser light is controlled according to the measured value. Therefore, regardless of the output of the invisible laser beam, the brightness of the visible laser beam can be made substantially constant, so that the area irradiated with the visible laser beam can be confirmed satisfactorily.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the entire device showing the first embodiment of the present invention, FIG. 2 is a plan view of the variable transmittance filter, and FIG.
4 and 4 are plan views of variable transmittance filters showing the second and third embodiments of the present invention, respectively, and FIGS. 5 and 6 show the fourth and fifth embodiments of the present invention, respectively. 1 is a configuration diagram of the entire device shown in FIG. 1... Laser oscillator, 5... Harmonic generator, 6...
...first wavelength selective transmission mirror (optical means), 12.
... power meter (measuring means), 13... variable transmittance filter (control means), 14a to 14f... first to sixth filter sections (control means), 15... drive device (
Control device). Applicant's agent Patent attorney Atsushi Tsuboi

Claims (1)

[Claims] a laser oscillator that generates an invisible laser beam, a harmonic generator that is provided in the optical path of the invisible laser beam and generates harmonics in the visible range from the invisible laser beam, and an optical system that separates the invisible laser beam and the harmonics. means, a measuring means for measuring the output of either the invisible laser beam or the harmonic, and a control provided in the optical path of the harmonic for controlling the output of the harmonic according to the measured value by the measuring means. A laser device characterized by comprising means.