JP2017223782A - Optical device and laser apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device capable of suppressing characteristic deterioration due to reflected light in a laser apparatus, and a laser apparatus including the optical device.SOLUTION: An optical device includes: an optical fiber 31; and a quartz block 35 having an incidence surface 35b connected to an end surface 31f of the optical fiber 31 and an emission surface 35a emitting light incident from the optical fiber 31. The incidence surface 35b of the quartz block 35 is larger than the end surface 31f of the optical fiber 31. The optical device includes a sensor 50 for detecting that reflected light incident from the emission surface 35a is incident to a position, of the incidence surface 35b, which is other than a portion connected to the optical fiber 31.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an optical device and a laser apparatus including the optical device.

  The fiber laser device is used in various fields such as a laser processing field and a medical field because it has excellent light condensing performance, has a high power density, and can obtain light as a small beam spot.

  The fiber laser device propagates and emits high-power laser light oscillated from an oscillator to an optical fiber, and irradiates a target irradiation position. With regard to such a high-power fiber laser device, for example, Patent Document 1 below discloses a connector device having a sensor for monitoring the state of the optical fiber at the incident end or the outgoing end of the optical fiber. This sensor is provided in or behind the connector device, and the laser light emitted from the optical fiber in the connector device and the reflected light that is reflected by the workpiece and returned to the optical fiber from the optical fiber. The scattered light emitted in the radial direction is detected.

Special table 2015-505969 gazette

  By the way, the laser beam emitted from the laser device is condensed by being passed through a processing head having a condensing lens, and is irradiated onto a processing object. The laser light applied to the object to be processed becomes heat by being absorbed by the object to be processed and contributes to the processing. However, a part of the laser light applied to the processing object is reflected by the surface of the processing object. When the laser beam ideally focused at the processing point is incident perpendicularly to the surface of the workpiece and reflected vertically, the reflected light is condensed again by the processing head and emitted from the laser beam. Recouple to fiber. However, in reality, ideal focusing is difficult due to the aberration of the lens of the processing head and the thermal lens effect. Furthermore, since the surface of the object to be processed is generally formed with minute irregularities and slopes, the reflected light reflected from the surface of the object to be processed is condensed at a position other than the optical fiber from which the laser beam is emitted. There is a case. When the reflected light is incident on a position other than the optical fiber in this way, it is difficult to detect the reflected light with the sensor disclosed in Patent Document 1 described above.

  As described above, when the reflected light is condensed at a position other than the optical fiber, for example, at a position other than the portion where the optical fiber is connected in the quartz block provided at the output end of the optical fiber, It has been found that the quartz block and the optical fiber are heated by this, which may cause problems such as deterioration of the characteristics of the laser device.

  Therefore, an object of the present invention is to provide an optical device capable of suppressing characteristic deterioration due to reflected light in a laser apparatus and a laser apparatus including the optical device.

  An optical device of the present invention includes an optical fiber, a quartz block having an incident surface to which an end surface of the optical fiber is connected, and an emission surface from which light incident from the optical fiber is emitted. A sensor for detecting the intensity of reflected light incident from the exit surface is provided at a position larger than the end face of the optical fiber and other than a portion of the entrance surface to which the optical fiber is connected.

  According to another aspect of the present invention, there is provided a laser apparatus comprising: the above-described optical device; and a light source that emits light propagating through the optical fiber.

  In the said invention, the intensity | strength of the reflected light which injects into positions other than the site | part to which an optical fiber is connected among the incident surfaces of a quartz block can be detected with a sensor. Therefore, the emission of the laser beam can be stopped before the quartz block or the optical fiber is heated by the reflected light and the characteristic of the laser device is deteriorated, and the characteristic deterioration of the laser device due to the reflected light can be suppressed.

  The sensor is preferably an optical sensor that detects the intensity of the reflected light that passes through the quartz block from a position other than a portion of the incident surface to which the optical fiber is connected.

  By using an optical sensor that detects the intensity of the reflected light, the intensity of the reflected light incident on a position other than the part to which the optical fiber is connected is measured on the incident surface of the quartz block, before the characteristics of the laser device deteriorate In addition, it is possible to control to stop the emission of the laser beam when the reflected light reaches a predetermined intensity. Therefore, it is possible to suppress the deterioration of the characteristics of the laser device due to the reflected light.

  A light-to-heat converter that converts the reflected light that is incident on a position other than the portion to which the optical fiber is connected on the incident surface into heat; and the sensor detects heat converted by the light-to-heat converter. It is preferable that the sensor be a thermal sensor.

  The intensity of the reflected light can be indirectly measured by converting the reflected light into heat by the photothermal converter and detecting the heat with a thermal sensor. Therefore, before the characteristics of the laser device deteriorate, it can be controlled to stop the emission of the laser light when the reflected light reaches a predetermined intensity, and the characteristic deterioration of the laser device due to the reflected light can be suppressed. .

  Moreover, it is preferable that the said photothermal conversion part is a light-scattering part formed in at least one part of positions other than the site | part to which the said optical fiber is connected among the said incident surfaces.

  The reflected light incident on the light scattering portion is scattered and incident many times on the light scattering portion, and is absorbed by the quartz block over a wide range and converted into heat. Therefore, the light scattering portion is a photothermal conversion portion. Thus, the photothermal conversion part can be formed with a simple configuration. In addition, by forming the light scattering portion at a position other than the part where the optical fiber is connected on the incident surface, it is possible to prevent high-intensity reflected light from passing through the quartz block and to connect light to the quartz block. Since it is suppressed that high intensity reflected light is irradiated to a fiber, it can suppress that an optical fiber is heated by reflected light.

  A housing for housing the quartz block and the optical fiber, wherein the thermal sensor is embedded in the housing, and heat from the photothermal converter is transmitted to the thermal sensor via the housing. preferable.

  By embedding the thermal sensor in the housing, it becomes easier to install the thermal sensor and the degree of freedom in designing the optical device can be improved.

  Further, it is preferable that the thermal sensor is disposed at a position overlapping the incident surface or closer to the exit surface than the entrance surface when viewed from a direction perpendicular to the central axis of the optical fiber.

  In an optical device having an optical fiber and a housing that accommodates the optical fiber, a space may be formed between the outer peripheral surface of the optical fiber and the inner peripheral surface of the housing, and the space may be filled with a refrigerant. Further, such a space is generally formed on the optical fiber side of the incident surface of the quartz block when viewed from a direction perpendicular to the central axis of the optical fiber. When the space is filled with the refrigerant, the casing is cooled by the refrigerant, so that the thermal sensor embedded in the casing detects the temperature of the cooled casing. However, as described above, the thermal sensor is disposed at a position overlapping the incident surface as viewed from the direction perpendicular to the central axis of the optical fiber or on the exit surface side from the incident surface, so that the thermal sensor is affected by the refrigerant. It becomes difficult to receive, and it becomes easy to accurately detect the heat from the light-to-heat converter by the thermal sensor.

  As described above, according to the present invention, an optical device capable of suppressing characteristic deterioration due to reflected light in a laser apparatus and a laser apparatus including the optical device are provided.

It is a conceptual diagram which shows the laser apparatus which concerns on 1st Embodiment of this invention. FIG. 2 is a cross-sectional view schematically showing a part of the optical device shown in FIG. 1. It is a figure which shows schematically the cross section of an optical device perpendicular | vertical to the central axis of the optical fiber along III-III shown in FIG. FIG. 3 is a cross-sectional view of the quartz block illustrated in FIG. 2 and a part of an optical fiber connected to the quartz block, and a diagram schematically illustrating an example of an optical path of reflected light. FIG. 3 is a cross-sectional view of the quartz block shown in FIG. 2 and a part of an optical fiber connected to the quartz block, and a diagram schematically illustrating another example of an optical path of reflected light. FIG. 3 is a cross-sectional view of the quartz block illustrated in FIG. 2 and a part of an optical fiber connected to the quartz block, and a diagram schematically illustrating still another example of the optical path of reflected light. The temperature detected by the thermal sensor and the laser beam when the incident light is incident on the incident surface of the quartz block with and without the light scattering portion. It is a graph which shows the relationship with irradiation time. It is sectional drawing which shows roughly a part of optical device which concerns on 2nd Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an optical device and a laser apparatus according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
<Laser device>
First, the configuration of the laser apparatus according to the first embodiment of the present invention will be described.

  FIG. 1 is a conceptual diagram showing a laser apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the laser apparatus 1 of the present embodiment includes a plurality of light sources 10, an optical combiner 20, and an optical device 30 as main components.

  Each light source 10 is a laser device that emits light of a predetermined wavelength, for example, a fiber laser device or a solid-state laser device. When the light source 10 is a fiber laser device, it may be a resonator type fiber laser device or a MO-PA (Master Oscillator Power Amplifier) type fiber laser device. The light emitted from each light source 10 is, for example, light having a wavelength of 1050 nm.

  Each light source 10 is connected to an optical fiber 11 that propagates light emitted from the light source 10. Each optical fiber 11 is, for example, a fu-mode fiber having a core diameter of about 20 μm. Accordingly, light emitted from each light source 10 propagates through each optical fiber 11 in the LP mode of about 2 to 4.

  The optical combiner 20 is a member that connects the core of each optical fiber 11 and the core of the optical fiber 21. For example, each optical fiber 11 and the optical fiber 21 having a diameter larger than that of the optical fiber 11 are end-face connected. Being done. The optical fiber 21 is, for example, a multimode fiber having a core diameter of about 50 μm to 100 μm.

  FIG. 2 is a cross-sectional view schematically showing a part of the optical device 30 shown in FIG. 1, and is a cross-sectional view parallel to the central axis of the optical fiber 31. FIG. 3 is a diagram schematically showing a cross section of the optical device 30 perpendicular to the central axis of the optical fiber 31 along III-III shown in FIG. 2, and is a view of the quartz block 35 side from the position of III-III. It is. As shown in FIGS. 2 and 3, the optical device 30 includes an optical fiber 31, a quartz block 35, a housing 40, and a thermal sensor 50 as main components.

  The optical fiber 31 is a part of the optical fiber 21 or another optical fiber having the same configuration as the optical fiber 21 connected to the optical fiber 21. The optical fiber 31 has a core 31a and a clad 31b surrounding the core 31a. A coating layer (not shown) is peeled off from the end face 31f within a range of about 20 mm from the end of the optical fiber 31 on the emission end side, and the end face 31f is fused to the quartz block 35 with an oxyhydrogen burner or the like. Such an optical fiber 31 is, for example, an optical fiber having a core 31a having a diameter of about 100 μm and a cladding 31b having an outer diameter of about 360 μm.

  The quartz block 35 is a columnar body made of quartz. The quartz block 35 is a cylindrical body made of quartz having a diameter of about 8 mm and a length of about 23 mm, for example. The quartz block 35 has an incident surface 35b to which the end surface 31f of the optical fiber 31 is connected and an output surface 35a from which light incident from the optical fiber 31 is emitted. The incident surface 35b is larger than the end surface 31f of the optical fiber 31, and the end surface 31f of the optical fiber 31 is fused to the center of the incident surface 35b.

  Since the incident surface 35b of the quartz block 35 is larger than the end surface 31f of the optical fiber 31 as described above, the incident surface 35b of the quartz block 35 has a portion that is not in contact with the end surface 31f of the optical fiber 31. A light scattering portion 36 is formed in a portion of the incident surface 35 b of the quartz block 35 that is not in contact with the end surface 31 f of the optical fiber 31. In the quartz block 35 of the present embodiment, the light scattering portion 36 is formed in the entire portion of the incident surface 35b of the quartz block 35 that is not in contact with the end face 31f of the optical fiber 31. The light scattering portion 36 is formed by, for example, forming the incident surface 35b roughly like a grain shape. When light enters such a light scattering portion 36, the light is scattered and incident many times on the light scattering portion 36, and is absorbed by the quartz block 35 in a wide range and converted into heat. Therefore, the light scattering unit 36 is a photothermal conversion unit that converts reflected light incident on a position other than the portion to which the optical fiber 31 is connected in the incident surface 35b into heat.

  The housing 40 is a member that houses part of the quartz block 35 and the optical fiber 31. The housing 40 is formed in a cylindrical shape, and the quartz block 35 and the optical fiber 31 are inserted therein. In the housing 40, the position of the quartz block 35 is fixed by fixing the outer peripheral surface 35c to the inner peripheral surface of the housing 40 with an adhesive such as silicone resin. A space 45 is formed between the inner peripheral surface of the housing 40 and the outer peripheral surface of the optical fiber 31. The space 45 may be filled with a coolant that cools the optical fiber 31, the quartz block 35, and the housing 40.

  The housing 40 is preferably made of a metal such as copper having excellent thermal conductivity, for example. Further, the outer peripheral surface of the housing 40 may be water-cooled or air-cooled according to the power of the laser light emitted from the laser device 1 or the like.

  The thermal sensor 50 is a sensor that indirectly detects the intensity of reflected light incident on a position other than a portion of the incident surface 35 b of the quartz block 35 to which the optical fiber 31 is connected from the emission surface 35 a of the quartz block 35. The thermal sensor 50 according to the present embodiment is embedded in the housing 40. The thermal sensor 50 detects heat generated when reflected light enters the light scattering portion 36 via the housing 40. Since the housing 40 is made of a metal having excellent thermal conductivity, heat generated by the light scattering portion 36 is easily transmitted to the thermal sensor 50. In this way, the thermal sensor 50 can detect the intensity of the reflected light incident on a position other than the portion to which the optical fiber 31 is connected on the incident surface 35b of the quartz block 35.

  By the way, the space 45 is formed on the optical fiber 31 side of the incident surface 35 b of the quartz block 35 when viewed from the direction perpendicular to the central axis of the optical fiber 31. Further, when the space 45 is filled with the refrigerant as described above, the casing 40 is cooled by the refrigerant, so that the thermal sensor 50 embedded in the casing 40 detects the temperature of the cooled casing 40. become. However, as shown in FIG. 2, the thermal sensor 50 is disposed at a position overlapping the incident surface 35 b of the quartz block 35 when viewed from the direction perpendicular to the central axis of the optical fiber 31. By disposing the thermal sensor 50 in this way, the thermal sensor 50 is hardly affected by the refrigerant, and the heat from the light scattering portion 36 can be easily detected accurately. From the same point of view, it is preferable that the thermal sensor 50 be disposed closer to the exit surface 35a than the entrance surface 35b when viewed from the direction perpendicular to the central axis of the optical fiber 31. However, the thermal sensor 50 is disposed at a position close to the light scattering unit 36 so that the heat from the light scattering unit 36 can be detected.

  As the thermal sensor 50, for example, a thermistor can be used. The thermal sensor 50 is connected to the interlock circuit 52 via a wiring 51 embedded in the housing 40. The interlock circuit 52 is configured so that the interlock is interrupted when the temperature detected by the thermal sensor 50 exceeds a predetermined threshold, and when the temperature detected by the thermal sensor 50 exceeds a predetermined threshold. Control is performed to stop the emission of laser light from the laser device 1. The threshold is preferably set in a range that does not adversely affect the quartz block 35 and the optical fiber 31.

  Next, the operation and action of the laser device 1 of the present embodiment will be described.

  When light of a predetermined wavelength is emitted from each light source 10, each light propagates through the optical fiber 11, is combined by the optical combiner 20, and is emitted from the optical device 30 via the optical fiber 21. In the optical device 30, the laser light propagates through the core 31 a of the optical fiber 31 and is emitted through the quartz block 35. The laser light incident on the quartz block 35 propagates through the quartz block 35 while spreading in accordance with the numerical aperture, is emitted from the emission surface 35a, is condensed by a machining head (not shown), and is irradiated onto the workpiece. The laser light applied to the object to be processed becomes heat by being absorbed by the object to be processed and contributes to the processing.

  However, a part of the laser light applied to the processing object is reflected by the surface of the processing object, and a part of the reflected light may enter the quartz block 35 again. Hereinafter, the reason why the optical device 30 can suppress the characteristic deterioration of the laser apparatus 1 due to such reflected light will be described.

  4 to 6 are diagrams schematically showing a sectional view of a part of the optical fiber 31 connected to the quartz block 35 and the quartz block 35 shown in FIG. 2 and an example of an optical path of reflected light, respectively.

  In the laser apparatus 1 of the present embodiment, when the laser beam emitted from the emission surface 35a of the quartz block 35 and ideally focused on the machining point is perpendicularly incident on the surface of the workpiece and reflected vertically The reflected light L1 passes through an optical path as shown in FIG. That is, the reflected light L1 is collected by a processing head (not shown) and forms a focal point f1 on the core 31a of the optical fiber 31 on the incident surface 35b side of the quartz block 35. As described above, when the reflected light L1 is recombined with the core 31a of the optical fiber 31, it is easy to detect the intensity of the reflected light L1, and thus the laser light emission can be safely stopped to cause a problem. It is easy to prevent. In this case, the reflected light L1 is hardly converted into heat, and problems such as heat generation due to the reflected light L1 hardly occur.

  However, in reality, ideal focusing is difficult due to the aberration of the lens of the processing head and the thermal lens effect. Further, since the surface of the processing object is generally formed with minute irregularities and slopes, the reflected light reflected by the surface of the processing object and returning to the quartz block 35 side is the core 31a of the optical fiber 31. A focal point is formed at a position shifted from the position. As shown in FIG. 5, when the focal point f2 of the reflected light L2 is formed on the cladding 31b of the optical fiber 31, the reflected light L2 becomes clad mode light propagating through the cladding 31b. In this case, by providing a cladding mode stripper or the like, the reflected light L2 that has become the cladding mode light can be intentionally emitted from a predetermined location, and heat generated by the conversion of the cladding mode light can be radiated by an appropriate method. can do. Accordingly, it is possible to suppress the problem of heat generation caused by the reflected light L2.

  When the focal position of the reflected light further deviates from the center of the optical fiber 31, as shown in FIG. 6, the focal point f3 of the reflected light L3 is at a position of the incident surface 35b of the quartz block 35 where the optical fiber 31 is not connected. It is formed. In this case, the reflected light L3 may heat the quartz block 35. When the quartz block 35 is heated in this way, problems such as deterioration of the characteristics of the laser apparatus 1 may occur.

  Here, the optical device 30 includes a light scattering unit 36 that functions as a photothermal conversion unit and a thermal sensor 50 that can detect heat generated in the light scattering unit 36. Therefore, when the reflected light is incident on a position where the optical fiber 31 is not connected in the incident surface 35b as in the reflected light L3, the reflected light is converted into heat by the light scattering unit 36, and the heat is detected by the thermal sensor 50. Since it can be detected, the intensity of the reflected light is indirectly measured by the thermal sensor 50. When the characteristics of the laser device 1 are deteriorated by the reflected light, the reflected light incident on a position other than the portion to which the optical fiber 31 is connected on the incident surface 35b before the characteristics of the laser device 1 deteriorate. It is assumed that Therefore, the laser device is controlled by setting the threshold value of the intensity of the reflected light and stopping the emission of the laser beam when the intensity of the reflected light indirectly measured by the thermal sensor 50 reaches the threshold value. The emission of laser light can be stopped before the characteristic of 1 is deteriorated. That is, when the reflected light reaches a predetermined intensity, it can be controlled to operate the interlock circuit 52 connected to the thermal sensor 50 to stop the emission of the laser light, and the characteristic deterioration of the laser device 1 due to the reflected light. Can be suppressed.

  Further, in the optical device 30, since the light scattering portion 36 is formed on the incident surface 35b of the quartz block 35, it is easy to detect the intensity of the reflected light incident on the incident surface 35b. FIG. 7 shows a thermal sensor when the incident surface 35b is irradiated with the laser beam having the same intensity with and without the light scattering portion 36 on the incident surface 35b of the quartz block 35. 5 is a graph showing the relationship between the temperature detected at 50 and the irradiation time of laser light. As can be seen from FIG. 7, the formation of the light scattering portion 36 increases the rate of temperature rise of the quartz block 35 with respect to the irradiation time of the laser light. That is, it can be seen that the formation of the light scattering portion 36 makes it easier for the quartz block 35 to absorb the reflected light, and the intensity of the reflected light can be detected at high speed and with high sensitivity.

  Further, in the optical device 30, the light scattering portion 36 is formed on the incident surface 35 b of the quartz block 35, whereby high-intensity reflected light is prevented from passing through the quartz block 35, and the optical fiber 31 has high intensity. Therefore, it is possible to prevent the optical fiber 31 from being heated by the reflected light.

  In the optical device 30, since the thermal sensor 50 is embedded in the housing 40, the thermal sensor 50 can be easily installed, and the degree of freedom in designing the optical device 30 can be improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described in detail with reference to FIG. In addition, about the component which is the same as that of 1st Embodiment, or equivalent, except the case where it demonstrates especially, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted.

  FIG. 8 is a cross-sectional view schematically showing a part of an optical device provided in the laser apparatus according to the second embodiment of the present invention. The optical device 30a shown in FIG. 8 is the same as the optical device 30 according to the first embodiment, except that the thermal sensor 50 is replaced with an optical sensor 55.

  The optical sensor 55 is a sensor that detects the intensity of reflected light that passes through the quartz block 35 from a position other than the portion to which the optical fiber 31 is connected on the incident surface 35 b of the quartz block 35. The optical sensor 55 is disposed toward the incident surface 35 b in the space 45, and can detect reflected light transmitted through the quartz block 35. As such an optical sensor 55, for example, a photodiode can be used.

  When the optical sensor 55 is used, the intensity of the reflected light incident on a position other than the part to which the optical fiber 31 is connected on the incident surface 35b of the quartz block 35 is measured, and the reflected light reaches a predetermined intensity. It is possible to control to stop the emission of laser light. That is, when the reflected light reaches a predetermined intensity, the interlock circuit 52 connected to the optical sensor 55 can be operated to control the emission of the laser light. Therefore, the characteristic deterioration of the laser apparatus 1 due to the reflected light can be suppressed.

  Further, a light scattering portion 36 is formed in the same manner as in the first embodiment except for a portion of the incident surface 35b of the quartz block 35 to which the optical fiber 31 is connected. By forming the light scattering portion 36 on the incident surface 35b, the reflected light incident on the incident surface 35b is scattered over a wide range. Therefore, it becomes easy to detect reflected light incident on a wide range of the incident surface 35b by the optical sensor 55. As a result, it is possible to suppress occurrence of a detection error of reflected light depending on the arrangement position of the optical sensor 55.

  Although the present invention has been described above by taking the first and second embodiments as examples, the present invention is not limited to these. For example, in the first embodiment, the light scattering part 36 formed on the incident surface 35b of the quartz block 35 has been described as an example of the photothermal conversion part. However, when the photothermal conversion unit is provided, the photothermal conversion unit may be any unit that can convert reflected light incident on a position other than the portion of the incident surface 35b of the quartz block 35 to which the optical fiber 31 is connected to heat. For example, by forming a light absorber on the incident surface 35b that can absorb the reflected light to such an extent that it is not burned by the reflected light, the light absorber may be used as a photothermal conversion part, and the incident surface 35b is subjected to black alumite processing. Thus, the portion subjected to the black alumite processing may be the photothermal conversion portion.

  Moreover, in 1st Embodiment, the whole surface except the site | part to which the optical fiber 31 was connected among the incident surfaces 35b of the quartz block 35 was given and demonstrated. However, the photothermal conversion part should just be formed in the site | part assumed that reflected light injects. For example, since it is considered that reflected light does not easily enter the outer peripheral portion of the incident surface 35b, the photothermal conversion unit may be formed at least around the portion of the incident surface 35b to which the optical fiber 31 is connected. The outer peripheral portion of the incident surface 35b may not be formed.

  In the first embodiment, an example in which the thermal sensor 50 is embedded in the housing 40 has been described. However, the installation position of the thermal sensor 50 may be any position that can detect heat generated in the photothermal conversion unit. For example, the thermal sensor 50 may be installed in contact with the photothermal conversion unit.

  In the second embodiment, an example in which the light scattering portion 36 is formed on the entire incident surface 35b of the quartz block 35 other than the portion to which the optical fiber 31 is connected has been described. However, in the second embodiment, the light scattering portion 36 is not essential. Further, when the light scattering portion 36 is formed in the second embodiment, the light scattering portion 36 only needs to be formed at a site where reflected light is assumed to be incident. For example, as described above, since it is considered that the reflected light does not easily enter the outer peripheral portion of the incident surface 35b, the light scattering portion 36 is formed around at least a portion of the incident surface 35b to which the optical fiber 31 is connected. It does not have to be formed on the outer peripheral portion of the incident surface 35b.

  In addition, for the sake of easy understanding, an example in which reflected light incident on the quartz block 35 from the emission surface 35a forms a single focal point on the incident surface 35b has been described. However, actually, the reflected light may enter the incident surface 35b with a certain extent. Accordingly, the reflected light may be incident on the incident surface 35b of the quartz block 35 across the position where the optical fiber 31 is not connected and the position where the optical fiber 31 is connected.

  As described above, according to the present invention, there is provided an optical device capable of suppressing characteristic deterioration due to reflected light in a laser apparatus, and a laser apparatus including the optical device, such as a processing machine and a medical laser apparatus. It is expected to be used in the field.

DESCRIPTION OF SYMBOLS 1 ... Laser apparatus 10 ... Light source 20 ... Optical combiner 30, 30a ... Optical device 31 ... Optical fiber 31a ... Core 31b ... Cladding 31f ... End surface 35 ... Quartz block 35a ... Outgoing surface 35b ... Incident surface 35c ... Outer peripheral surface 36 ... Light scattering part (photothermal conversion part)
40 ... Case 50 ... Thermal sensor (sensor)
55 ... Optical sensor (sensor)

Claims (7)

Optical fiber,
A quartz block having an entrance surface to which an end face of the optical fiber is connected and an exit surface from which light incident from the optical fiber is emitted;
With
The incident surface is larger than the end surface of the optical fiber;
An optical device comprising: a sensor that detects the intensity of reflected light incident from the exit surface at a position other than a portion of the entrance surface to which the optical fiber is connected. The said sensor is an optical sensor which detects the intensity | strength of the said reflected light which permeate | transmits the said quartz block from positions other than the site | part to which the said optical fiber is connected among the said incident surfaces. Optical device. A light-to-heat converter that converts the reflected light that is incident on a position other than a portion of the incident surface to which the optical fiber is connected, into heat;
The optical device according to claim 1, wherein the sensor is a thermal sensor that detects heat converted by the photothermal conversion unit. The optical device according to claim 3, wherein the photothermal conversion unit is a light scattering unit formed at least at a part of the incident surface other than a portion to which the optical fiber is connected. A housing for housing the quartz block and the optical fiber;
The thermal sensor is embedded in the housing;
5. The optical device according to claim 3, wherein heat from the light-to-heat conversion unit is transmitted to the thermal sensor through the housing. 6. The light according to claim 5, wherein the thermal sensor is disposed at a position overlapping the incident surface or closer to the exit surface than the entrance surface when viewed from a direction perpendicular to a central axis of the optical fiber. device. The optical device according to any one of claims 1 to 6,
A light source that emits light propagating through the optical fiber;
A laser device comprising:

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