Laser light source device and laser light source device application equipment

Abstract

The laser light source device (1) includes a laser light source (11) having a first end face (11a) and a second end face (11b), a focusing lens (12) that converts light (L1) emitted from the first end face (11a) into focused light (L2) that focuses at a focusing point, and a reflective diffraction grating (13) that receives the focused light (L2) at the focusing point and generates diffracted light from the focused light (L2) toward the focusing lens (12). The laser light source (11), the focusing lens (12), and the reflective diffraction grating (13) are arranged so that diffracted light (L3) toward the focusing lens (12) passes through the focusing lens (12) to be incident on the first end face (11a), and passes through the laser light source (11) to be emitted from the second end face (11b).

Description

[Technical field]

[0001] The present disclosure relates to a laser light source device and an apparatus to which a laser light source device is applied. [Background technology]

[0002] There has been a proposal for an external resonance type laser light source device that includes a laser light source, a diffraction grating that diffracts the light emitted from the laser light source and passed through a lens, and a reflecting mirror with a variable tilt angle (see, for example, Patent Document 1). In this device, the grating spacing of the diffraction grating is modulated according to the divergence angle of the divergent light, and the reflected and diffracted light traveling from the diffraction grating to the reflecting mirror is made into parallel light. With this configuration, light of a specific wavelength can be fed back to the laser light source, and laser oscillation can be achieved at a specific wavelength. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4984537 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a small optical system including a lens, it is difficult to create strictly parallel light, and the reflected and diffracted light from the diffraction grating to the reflecting mirror contains divergent light components, which reduces the coupling efficiency. Also, in order to improve the coupling efficiency and achieve high efficiency, it is necessary to enlarge the optical system.

[0005] The present disclosure has been made to solve the above-mentioned problems in the related art, and has an object to provide a small-sized and highly efficient laser light source device and an apparatus to which the laser light source device is applied that has the same. [Means for solving the problem]

[0006] The laser light source device of the present disclosure includes a laser light source having a first end face and a second end face, a focusing lens that converts light emitted from the first end face into focused light that is focused at a focusing point, and a reflective diffraction grating that receives the focused light at the focusing point and generates diffracted light from the focused light that travels toward the focusing lens; a diffraction grating drive unit that rotates the reflection type diffraction grating around a support shaft that supports the reflection type diffraction grating; having shifting the focusing point from the position of the support shaft, which is the rotation center of the diffraction grating drive unit, and rotating the reflective diffraction grating around the support shaft, thereby changing the distance from the focusing lens to the focusing point; The laser light source, the condenser lens, and the reflective diffraction grating are directed toward the condenser lens. The above The optical fiber is characterized in that the optical fiber is arranged so that diffracted light passes through the focusing lens, enters the first end face, passes through the laser light source, and exits from the second end face. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a small-sized and highly efficient laser light source device and an apparatus including the same that employs the laser light source device. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a laser light source device according to a first embodiment. [Diagram 2] 2 is a schematic diagram showing the side and front views of the reflective diffraction grating of FIG. 1. [Diagram 3] 13(A) and 13(B) are diagrams illustrating a schematic configuration of a laser light source device according to a second embodiment. [Figure 4] 3(A) is a diagram showing a schematic side and front view of the reflective diffraction grating of FIG. 3(A), and FIG. 3(B) is a diagram showing a schematic side and front view of the reflective diffraction grating of FIG. 3(B). [Diagram 5] FIG. 11 is a diagram illustrating a schematic configuration of a laser light source device according to a third embodiment. [Figure 6] FIG. 11 is a diagram illustrating a schematic configuration of a laser light source device according to a fourth embodiment. [Figure 7] FIG. 11 is a block diagram illustrating a schematic configuration of a control system of a laser light source device according to a fourth embodiment. [Figure 8]FIG. 13 is a diagram illustrating a schematic configuration of a blood glucose measuring instrument as an application instrument of a laser light source device according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a laser light source device and an apparatus to which the laser light source device is applied according to the embodiments will be described with reference to the drawings. The following embodiments are merely examples, and the embodiments can be appropriately combined and each embodiment can be appropriately modified.

[0010] To facilitate understanding of the relationships between the figures, the figures also show coordinate axes of an xyz Cartesian coordinate system, where the z-axis is oriented in the direction of the optical axis of the laser light emitted from the laser light source device, and the x-axis and y-axis are oriented in directions perpendicular to the z-axis.

[0011] Embodiment 1 Fig. 1 is a diagram illustrating a schematic configuration of a laser light source device 1 according to embodiment 1. Fig. 2 is a diagram illustrating a schematic side and front view of a reflective diffraction grating 13 in Fig. 1. The laser light source device 1 is an external resonance type laser light source device.

[0012] The laser light source device 1 has a laser light source 11 having a first end face 11a and a second end face 11b, a focusing lens 12 that converts light L1 emitted from the first end face 11a into focusing light L2 that focuses at a focusing point 13a, and a reflective diffraction grating 13 that receives the focusing light L2 at the focusing point 13a and generates diffracted light from the focusing light L2 that travels toward the focusing lens 12.

[0013] The laser light source 11, the condensing lens 12, and the reflective diffraction grating 13 are disposed in a housing 10. The laser light source 11, the condensing lens 12, and the reflective diffraction grating 13 are disposed so that diffracted light L3 (first-order diffracted light DL1 in FIG. 1) traveling from the reflective diffraction grating 13 toward the condensing lens 12 passes through the condensing lens 12 and enters the first end face 11a as focused light L4, and passes through the laser light source 11 and is emitted to the outside from the second end face 11b as emitted light L5.

[0014] The laser light source 11 is a semiconductor laser (i.e., a laser diode) and is also called a light source chip. The first end face 11a and the second end face 11b are faces facing opposite each other in the laser light source 11. The laser light source 11 emits, for example, light in the LWIR (Long Wavelength InfraRed) band, that is, long-wave infrared light with a wavelength of 8 μm to 12 μm.

[0015] The condenser lens 12 is, for example, a chalcogenide glass lens or a germanium lens. The condenser lens 12 focuses the light passing through it to a focal point. The condenser lens 12 is a single lens, but may be a compound lens.

[0016] Reflective diffraction grating 13 has a linear groove structure (i.e., a plurality of grooves extending in the x-axis direction) that is equally spaced (i.e., at an equal pitch). The grooves of reflective diffraction grating 13 are, for example, equally spaced in a direction perpendicular to the x-axis. In the first embodiment, a distance D0 in the z-axis direction from the center position of focusing lens 12 in the z-axis direction to focusing point 13a of focusing lens 12 is fixed. Also, in the first embodiment, the inclination angle of reflective diffraction grating 13 with respect to the z-axis is fixed. It is possible to use a reflective diffraction grating 13 in which the linear groove structures are not equally spaced.

[0017] In the first embodiment, the convergent light is focused toward the focal point 13a on the reflective diffraction grating 13. In the case where parallel light is incident on the reflective diffraction grating, for example, if the angle of the reflective diffraction grating 13 is shifted, the return path is significantly shifted from the forward path, the focal position on the first end face 11a of the laser light source 11 is shifted, and the amount of light returned is significantly reduced. In contrast, when the convergent light is incident on the reflective diffraction grating 13 of the present invention, only the spreading direction of the light on the return path is shifted from the forward path, so the focal position on the first end face 11a of the laser light source 11 is hardly shifted, and there is almost no reduction in the amount of light returned from the reflective diffraction grating 13 to the first end face 11a of the laser light source 11. In addition, when the convergent light is incident on the focal point 13a of the reflective diffraction grating 13, the size of the reflective diffraction grating 13 can be made extremely small.

[0018] Generally, it is difficult to convert divergent light into strictly parallel light using a small and inexpensive optical lens, so the coupling efficiency between the reflective diffraction grating and the laser light source is likely to decrease. In contrast, in the laser light source device 1 according to the first embodiment, when the light L1 emitted from the first end face 11a of the laser light source 11 is converted into converging light L2 that is converged on the converging point 13a on the reflective diffraction grating 13 by the converging lens 12, the coupling efficiency between the reflective diffraction grating 13 and the laser light source 11 is unlikely to decrease. Therefore, the laser light source device 1 according to the first embodiment can obtain high efficiency characteristics while being small in size.

[0019] In addition, generally, when the size of the entire optical system is reduced, there is a problem that the diffraction of light cannot be ignored. For example, in the case of a typical optical system, the diameter of the light beam is three or more orders of magnitude larger than the wavelength (i.e., "wavelength x 10 3 In the case of an optical system that handles light rays having a beam diameter of 100 nm or more (light beam diameter of 100 nm or more), diffraction of light can be ignored. Therefore, when designing focusing lens 12, by minimizing the aberration of focusing lens 12, the size of the focused spot by focusing lens 12 can be minimized.

[0020] However, the diameter of the light beam is not three orders of magnitude larger than the wavelength (i.e., "wavelength × 103 In the case of an optical system that handles light rays with a beam diameter of less than r, the spread of light rays caused by the diffraction of light that is not considered geometrically (i.e., the spread of diffracted light) cannot be ignored. In this case, the diffracted light due to the diffraction of light spreads parabolically, so the spread of the diffracted light is r 2 (r is the distance from the optical axis). This relationship is the same as that when defocusing is performed (i.e., when the evaluation surface on which the focused spot is formed is slid to several positions to find the best position for the focused spot state and the state of the focused spot at each position is evaluated). For this reason, in most cases, the state of the focused spot is corrected by shifting (i.e., defocusing) the evaluation surface from the designed focal length (i.e., the focal length when diffracted light is ignored).

[0021] However, when defocused, the diameter of the luminous flux of the focused spot increases by r 2 In addition, when the amount of shift in the optical axis direction for correcting the state of the focused spot (i.e., the amount of defocus) is large, the effect of spherical aberration cannot be ignored.

[0022] Therefore, the above problem can be solved by adding spherical aberration to the design of the condenser lens 12 as a design residual aberration so as to cancel the spherical aberration. That is, it is desirable to design the condenser lens so that the spherical aberration at the focusing point is minimized when a defocus amount for correcting the focusing state is applied. In other words, when the size of the entire optical system is small, there is a problem that the diffraction of light cannot be ignored, so in order to solve this problem, it is desirable to design the condenser lens 12 so that it has spherical aberration as a design residual aberration.

[0023] Embodiment 2 3(A) and (B) are diagrams that show a schematic configuration of a laser light source device 2 according to the second embodiment. In Fig. 3(A) and (B), the same reference numerals as those shown in Fig. 1 are used to designate the same components as those shown in Fig. 1. Fig. 4(A) is a diagram that shows a schematic side and front view of the reflective diffraction grating 13 in Fig. 3(A), and Fig. 4(B) is a diagram that shows a schematic side and front view of the reflective diffraction grating 13 in Fig. 3(B). In Fig. 4(A) and (B), the same reference numerals as those shown in Fig. 2 are used to designate the same components as those shown in Fig. 2.

[0024] The laser light source device 2 according to the second embodiment is a variable wavelength light source device configured to be able to change the wavelength of the output light L5 emitted from the second end face 11b to the outside within a predetermined range. The laser light source device 2 can change the wavelength of the output light L5 continuously or stepwise within a predetermined wavelength band. The predetermined wavelength band is, for example, the LWIR band, and is within a wavelength range of 8 μm to 12 μm.

[0025] The laser light source device 2 of embodiment 2 differs from the laser light source device 1 of embodiment 1 in that it further includes a diffraction grating driver 15 that changes the distance from the focusing lens 12 to the focusing point 13a, which is the point of incidence of the focused light L2 on the reflective diffraction grating 13, by rotating the reflective diffraction grating 13 around a support axis 14 that supports the reflective diffraction grating 13, and in that the focusing point 13a, which is the point of incidence of the focused light L2 on the reflective diffraction grating 13, is away from the position of the support axis 14 (away generally in the y-axis direction).

[0026] The diffraction grating driver 15 is, for example, a driver mechanism that uses electromagnetic force as a driving force, a driver mechanism that uses the rotation of a motor as a driving force, or a driver mechanism that uses the displacement of a piezoelectric element as a driving force, etc. The support shaft 14 is rotatably supported by the housing 10, and the tilt angle with respect to the z-axis direction can be changed by the driving force generated by the diffraction grating driver 15.

[0027] In embodiment 2, by rotating reflective diffraction grating 13 by diffraction grating driver 15, it is possible to shorten the z-axis distance from the center position of focusing lens 12 in the z-axis direction to focusing point 13a of focusing lens 12 (distance D1 is shown in the figure) as shown in FIG. 3(A), and to lengthen the z-axis distance from the center position of focusing lens 12 in the z-axis direction to focusing point 13a of focusing lens 12 (distance D2 is shown in the figure) as shown in FIG. 3(B).

[0028] Reflective diffraction grating 13 has wavelength dependency in that the diffraction angle of the diffracted light is smaller for shorter wavelengths and larger for longer wavelengths. That is, when laser oscillation is desired at a short wavelength, it is necessary to control diffraction grating driver 15 so that the tilt angle of reflective diffraction grating 13 with respect to the y axis is made smaller (i.e., the tilt angle with respect to the z axis is made larger), and when laser oscillation is desired at a long wavelength, it is necessary to control diffraction grating driver 15 so that the tilt angle of reflective diffraction grating 13 with respect to the y axis is made larger (i.e., the tilt angle with respect to the z axis is made smaller).

[0029] In addition, chromatic aberration occurs in the light transmitted through the condenser lens 12 due to dispersion. Therefore, the condenser point 13a of the light with a short wavelength is located near the condenser lens 12, and the condenser point 13a of the light with a long wavelength, which is longer than the short wavelength, is located farther from the condenser lens 12 than the condenser point in the case of the short wavelength. In other words, the refractive index of the condenser lens 12 is larger for the light with a short wavelength and is smaller for the light with a long wavelength, so that the distance D1 to the condenser point in the case of the light with a short wavelength is shorter than the distance D2 to the condenser point in the case of the light with a long wavelength. In this way, by shifting the condenser point from the position of the support shaft 14, which is the rotation center (shifting it roughly in the y-axis direction), the distance between the condenser lens 12 and the reflective diffraction grating 13 changes according to the tilt angle of the reflective diffraction grating 13 with respect to the y-axis, and therefore defocusing can be prevented by matching the change in this distance with the change in the condenser point in the z-axis direction due to chromatic aberration.

[0030] In the cases of Figures 3(A) and 4(A), short wavelength light is focused at the focusing point 13a of the reflective diffraction grating 13, and the wavelength of the output light L5 is short wavelength light. In contrast, in the cases of Figures 3(B) and 4(B), long wavelength light is focused at the focusing point 13a of the reflective diffraction grating 13, and the wavelength of the output light L5 is long wavelength light. In this way, the laser light source device 2 according to the second embodiment can change the wavelength of the output light L5 while preventing defocusing by rotating the reflective diffraction grating 13 by the diffraction grating driver 15.

[0031] Except for the above, the second embodiment is the same as the first embodiment.

[0032] Embodiment 3 FIG. 5 is a diagram showing a schematic configuration of a laser light source device 3 according to the third embodiment. In FIG. 5, the same reference numerals as those shown in FIG. 1 are used for the same or corresponding components as those shown in FIG. 1. The laser light source device 3 according to the third embodiment is different from the laser light source device 1 according to the first embodiment in that it further includes a photodetector 16 arranged on the optical path of the zero-order diffracted light DL0 generated by the reflective diffraction grating 13. The laser light source device 3 according to the third embodiment further includes a condenser lens 17 that converts the output light L5 into a parallel light L6. The condenser lens 17 may be provided in the laser light source device 1 according to the first embodiment.

[0033] The photodetector 16 has one or more light receiving elements. In general, the smaller the beam diameter of the light incident on the light receiving surface of the light receiving element, the wider the frequency band of light that can be detected by the light receiving element. Therefore, in order to operate at high speed, it is desirable to reduce the beam diameter of the zeroth order diffracted light DL0 incident on the light receiving element. In the third embodiment, since the focused light L2 is incident on the focusing point 13a on the reflective diffraction grating 13, the light receiving element of the photodetector 16 can be brought closer to the reflective diffraction grating 13 to reduce the incident beam diameter of the zeroth order diffracted light DL0.

[0034] In addition, by using a light receiving element with a light receiving area divided into two (or a light receiving element with more than two divisions) as the light receiving element of the photodetector 16, the position of the light focusing point 13a of the incident light can be measured. The detection signal at this time corresponds to the tilt angle of the reflective diffraction grating 13, so the oscillation wavelength of the laser light source 11 can be measured based on the detection signal. Usually, when the light receiving area of ​​the light receiving element is divided into two, the boundary between the two areas is a straight line parallel to the x-axis direction. In this case, for example, the tilt angle of the reflective diffraction grating 13 may be controlled so that the balance of the amount of light received by the two areas is a predetermined ratio (for example, balanced).

[0035] According to the laser light source device 3 according to the third embodiment, it is possible to obtain highly efficient characteristics while being compact. Also, the oscillation wavelength of the laser light source 11 can be set based on the detection signal of the photodetector 16.

[0036] Except for the above, the third embodiment is the same as the first or second embodiment.

[0037] Embodiment 4 FIG. 6 is a diagram showing a schematic configuration of the laser light source device 4 according to the fourth embodiment. In FIG. 6, the same reference numerals as those shown in FIGS. 3(A) and (B) are used for the configurations that are the same as or correspond to those shown in FIGS. 3(A) and (B). The laser light source device 4 according to the fourth embodiment is different from the laser light source device 2 according to the second embodiment in that it further includes a photodetector 16 arranged on the optical path of the zero-order diffracted light DL0 generated by the reflective diffraction grating 13. The laser light source device 4 according to the fourth embodiment further includes a condenser lens 17 that converts the emitted light L5 into parallel light L6. The condenser lens 17 may be provided in the laser light source device 2 according to the second embodiment. The configuration and operation of the photodetector 16 are the same as those described in the third embodiment.

[0038] FIG. 7 is a block diagram showing a schematic configuration of a control system of the laser light source device 4 according to the fourth embodiment. The laser light source device 4 has a control unit 18 configured with a control circuit. The control unit 18 controls the operation of the laser light source 11 and the diffraction grating driver 15 based on the detection signal of the photodetector 16. The control unit 18 controls the diffraction grating driver 15, so that the oscillation wavelength of the laser light source 11 can be automatically set to a desired value. The desired value is, for example, a value within a wavelength range of 8 μm to 12 μm, which is the LWIR band. Furthermore, the control unit 18 controls the diffraction grating driver 15, so that the oscillation wavelength of the laser light source 11 can be changed within a desired range (for example, periodically varied).

[0039] The laser light source device 4 according to the fourth embodiment can obtain high-efficiency characteristics while being compact. Furthermore, the control unit 18 can automatically set the oscillation wavelength of the laser light source 11 to a desired value. Furthermore, the oscillation wavelength can be changed within a predetermined wavelength range by the control of the control unit 18.

[0040] Furthermore, since the round-trip optical path length can be changed according to the tilt angle of reflective diffraction grating 13 by shifting the focusing point on reflective diffraction grating 13, the amount of light coupled to laser light source 11 can be maximized by setting the amount of shift of the focusing point on reflective diffraction grating 13 so that the shift in the focal position caused by focusing lens 12 and the shift in the optical path length according to the tilt angle of reflective diffraction grating 13 with respect to the y-axis cancel each other out.

[0041] Except for the above, the fourth embodiment is the same as any one of the first to third embodiments.

[0042] Embodiment 5. FIG. 8 is a diagram showing a schematic configuration of a blood glucose level meter 5 as a laser light source device application device according to the fifth embodiment. The blood glucose level meter 5 is a non-invasive blood glucose level sensor. The blood glucose level meter 5 has laser light source devices 1-4 that irradiate a target with light in the LWIR band from the second end face 11b of the laser light source 11, and a heat generation detection unit that detects the amount of heat generated by a target (e.g., a living body 50) due to heat absorption by the light in the LWIR band. The amount of heat generation corresponds to the blood glucose level of blood flowing through the living body. In the fifth embodiment, the heat generation detection unit is composed of a probe light source 51, a prism 52, and a position detection element 53. However, the structure and detection principle of the heat generation detection unit are not limited to those shown in FIG. 8.

[0043] The blood glucose level can be detected by measuring the absorption spectrum of the living body 50. The pump light L emitted from the laser light source device 1 (or 2, 3, 4) can be swept with the wavelength of the LWIR band light (wavelength 8 to 12 μm), which is a wavelength band suitable for observing the absorption spectrum of the living body 50, particularly the blood glucose level. The prism 52 is a place where the living body 50 is placed (i.e., a contact member) and is made of a material that can transmit the LWIR band light. In addition, heat generated by the heat generation accompanying the absorption of the pump light L by the living body 50 is transmitted to the prism 52, and the refractive index distribution of the prism 52 changes according to the amount of heat generated. Therefore, a refractive index distribution corresponding to the heat distribution is formed in the prism 52. By irradiating the probe light P generated by the probe light source 51 so as to cross an area having a refractive index distribution corresponding to such a heat distribution, the optical path of the probe light P is bent according to the refractive index distribution, and the spot position for detecting the probe light P changes, and the amount of change can be detected by the position detection element 53. As described above, this amount of change can be converted into the amount of heat generated, so that the absorption spectrum of the living body 50 can be measured in this configuration example.

[0044] The control device 54 controls the laser light source device 1 (or 2, 3, or 4) and the probe light source 51, performs calculations for converting the detection signal of the position detection element 53 into a blood glucose level, and can display the result on a display device, for example.

[0045] Furthermore, by shifting the focusing point on reflective diffraction grating 13, the round-trip optical path length can be changed according to the tilt angle of reflective diffraction grating 13 with respect to the y-axis. Therefore, if the shift amount of the focusing point on reflective diffraction grating 13 is set so that the shift amount of the focal position caused by collecting lens 12 and the shift amount of the optical path length according to the tilt angle of reflective diffraction grating 13 with respect to the y-axis cancel each other out, the amount of light coupled to laser light source 11 can be maximized.

[0046] Except for the above, the fifth embodiment is the same as any one of the first to fourth embodiments.

[0047] Furthermore, the laser light source device may be used in an apparatus other than a blood glucose meter. [Explanation of symbols]

[0048] 1 to 4 laser light source device, 5 blood glucose meter (apparatus to which laser light source device is applied), 11 laser light source, 11a first end face, 11b second end face, 12 focusing lens, 13 reflective diffraction grating, 13a focusing point (incident point), 14 support shaft (center of rotation), 15 diffraction grating drive unit, 16 photodetector, 17 lens, 18 control unit, 51 probe light source, 52 prism, 53 position detection element.

Claims

1. a laser light source having a first end face and a second end face; a condenser lens that converts the light emitted from the first end face into a condensed light that is condensed at a condensing point; a reflective diffraction grating that receives the focused light at the focusing point and generates diffracted light from the focused light toward the focusing lens; a diffraction grating drive unit that rotates the reflection type diffraction grating around a support shaft that supports the reflection type diffraction grating; having shifting the focusing point from the position of the support shaft, which is the rotation center of the diffraction grating drive unit, and rotating the reflective diffraction grating around the support shaft, thereby changing the distance from the focusing lens to the focusing point; The laser light source, the condenser lens, and the reflective diffraction grating are arranged such that the diffracted light traveling toward the condenser lens passes through the condenser lens, enters the first end face, and passes through the laser light source to exit from the second end face. A laser light source device characterized by:

2. The reflective diffraction grating has a plurality of equally spaced linear grooves.

2. The laser light source device according to claim 1 .

3. The reflective diffraction grating has a plurality of equally spaced linear grooves, The direction in which the support shaft extends is the same as the longitudinal direction of the linear groove.

2. The laser light source device according to claim 1 .

4. The diffraction grating further includes a photodetector disposed on an optical path of the zero-order diffracted light generated by the reflection type diffraction grating.

2. The laser light source device according to claim 1 .

5. The diffracted light traveling toward the focusing lens is first-order diffracted light.

2. The laser light source device according to claim 1 .

6. The condenser lens has spherical aberration as a residual aberration in design.

2. The laser light source device according to claim 1 .

7. a laser light source device according to claim 1 , which irradiates the light in the LWIR band as pump light toward a target from the second end surface of the laser light source; a heat generation detection unit that detects heat generation of the target due to heat absorption of the pump light; A laser light source device according to claim 1,

8. The subject is a living body, The amount of heat generated corresponds to the blood sugar level in the blood flowing through the living body.

8. An apparatus to which the laser light source device according to claim 7 is applied.

9. The heat detection unit includes: a prism that comes into contact with the object and generates a change in refractive index corresponding to heat transferred from the object; a probe light source that inputs a probe light to the prism; a position detection unit that detects the position of the probe light transmitted through the prism; 8. An apparatus to which a laser light source device is applied according to claim 7, further comprising:

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