JP2010056265A - Laser light source, two-dimensional image display device using laser light source, liquid crystal display, and medical laser light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: although air serves as a clad at a connection part where a coating is absent between a rare-earth added double-clad fiber and a general single-mode fiber to confine remaining pumping light, pump light leaks in a part having a coating and then the fibers partially generate heat with the energy thereof to deteriorate to be broken. <P>SOLUTION: A remaining pumping light absorbing, diverging, and reflecting mechanism is provided at the connection part between the double-clad fiber and single-mode fiber to prevent fiber deterioration due to the remaining pumping light which is a problem of a fiber laser light source for linear polarized light and to achieve single polarization in a simple method. Consequently, reliability is improved and there is no limitation to pumping high output, thereby increasing oscillation optical output. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fiber laser light source having an oscillation wavelength of 1040 nm to 1070 nm.

  In recent years, fiber laser light sources with high efficiency, excellent beam quality, air cooling, and simple structure have attracted attention as near-infrared laser light sources that replace conventional solid-state laser light sources. . FIG. 1 shows a schematic configuration diagram of a typical fiber laser light source. Laser light emitted from the pumping (pump) LD 101 is incident on a Yb-doped double-clad polarization maintaining fiber 103 that is a laser medium, and in a laser resonator that is composed of fiber gratings 102 and 104 that are reflection mirrors. Laser light oscillates by resonating. The single polarization mechanism (polarizer) 105 shown in the figure is inserted in order to make the polarization direction of the oscillated laser light unitary. Since this fiber laser has good beam quality and the oscillation wavelength spectrum can be defined by the line width of the reflection spectrum at the exit side fiber grating, the fiber laser is used as a fundamental light source and a harmonic optical crystal is used. Very suitable for wave generation (called wavelength conversion light source). The SHG module 108 shown in FIG. 1 is a mechanism for generating the second harmonic. By using this mechanism, the second harmonic 107 is finally emitted. In addition, in the conventional solid-state laser, the oscillation wavelength of the laser is defined by the laser crystal to be used. However, in this fiber laser, the oscillation wavelength is also defined by a set of fiber gratings. It has the feature that the wavelength can be changed arbitrarily.

On the other hand, a laser display attracts attention as an application using such harmonics of laser light as a light source (wavelength conversion light source) (for example, see Non-Patent Document 1). Compared with the white lamps used so far, the generation of unnecessary infrared rays and ultraviolet rays can be kept low, so that power consumption can be kept low and light can be efficiently collected by using a laser. It becomes possible, and the utilization efficiency of light can be improved. Further, since the laser is monochromatic light and has high color purity as compared with the case where a light emitting diode is used, the color reproducibility of the display device can be improved. In particular, a deeper green color can be expressed by setting the wavelength of green light to 520 to 535 nm. FIG. 2 shows a color reproduction range for each wavelength of green light to be used when the wavelength of blue light on the chromaticity diagram is 460 nm and the wavelength of red light is 635 nm. Such a wavelength can only be generated at two wavelengths of 532 nm when Nd: YAG or Nd: YVO ₄ is used when a solid-state laser is used, or 527 nm when Nd: YLF is used. Since it is difficult to manufacture with a compound crystal, a fiber laser that has a broad fluorescence spectrum and can freely select an oscillation wavelength has been promising (see, for example, Non-Patent Document 2).

On the other hand, in the fiber laser or the fiber amplifier, since the pumping light and the oscillation light propagate on the same fiber, as shown in Patent Document 1, a part of the oscillated light becomes inadvertent return light, and the pumping light source As a result, methods of avoiding oscillation light using a lens system and a mirror have been studied.
Japanese Patent No. 3012034 Japan Journal of Applied Physics Vol. 43, no. 8B, 2004, pp. 5904-5906 Rare-earth-doped Fiber lasers and amplifiers, (Marcel Dekker, Inc. 2001) page 145 figure10.

  As a green light source of the laser display, it is desirable that the wavelength is in the range of 530 nm to 520 nm in terms of the color reproduction range, but when using a wavelength conversion light source using a fiber laser as a fundamental wave light source, With light of 1075 nm or less, which is the fundamental wave, absorption exists in the rare-earth doped fiber that is the laser medium, and the (oscillation) operation of the laser resonator becomes unstable, so the fiber length that is the interaction length cannot be increased. . This phenomenon becomes prominent in a polarization maintaining fiber such as a PANDA fiber used to obtain linearly polarized light that is essential in the case of a wavelength conversion light source.

  On the other hand, in order to increase the output of laser light, it is necessary to increase the excitation light. However, depending on the wavelength of the excitation light, the fiber deteriorates or breaks due to the excitation light that is not absorbed by the rare earth doped fiber that is the laser medium. There was a problem to do. The mechanism of deterioration is shown using FIG. FIG. 4 shows a connection 110 between a rare earth-doped double clad fiber and a general single mode fiber. The double clad fiber has a structure in which light propagates through the inner clad portion 403 with the residual excitation light 408 confined in the outer clad 402. On the other hand, after connection with the single mode fiber, air becomes a clad in the portion where the coating 407 is not provided, and the residual pumping light 408 is confined. However, the pump light oozes out in the portion having the coating, and the energy is partially reflected by the energy. It generates heat (for example, the heat generating portion 409), and deteriorates or breaks.

  As an example of a method for solving such a phenomenon, FIG. 5 shows an absorption spectrum of a fiber doped with about 1000 ppm of Yb as a rare earth and will be described. As the excitation light, a laser diode (LD) near 915 nm or a laser diode near 976 nm can be used. At this time, the absorption amount of 915 nm light of this fiber is about 0.6 dB / m, whereas the absorption amount of 976 nm light is about 1.8 dB / m, which is about three times larger. Although it is considered that the degradation of the fiber can be solved, since the shape of the absorption peak is steep near 976 nm, it is broad near 915 nm, so that the wavelength variation of the excitation light caused by the temperature change of the excitation light LD is caused. On the other hand, it is more stable to use the 915 nm band (900 to 950 nm), and the LD cooling mechanism can be simplified. Therefore, apparatus cost and power consumption can be reduced. As described above, it has heretofore been difficult to achieve both temperature stability of the fiber laser device and linearly polarized light of 6 W or more and 1100 nm or less with the fiber laser.

  As another problem, in a wavelength conversion laser light source using a fiber laser light source as a fundamental wave, the fundamental wave emitted from the fiber laser needs to be a single polarization. In this case, a component called a polarizer is required for single polarization, but the cost is high and the transmission loss of the laser light increases, and the efficiency of the fiber laser resonator (from pumping light to oscillation light) There was also a problem that the conversion efficiency was reduced.

  In order to solve the above-mentioned problems, a laser light source device of the present invention is arranged at both ends of a rare earth doped double clad fiber as a laser active material, an excitation semiconductor laser for exciting the double clad rare earth doped fiber, and the double clad rare earth doped fiber. A set of fiber gratings composed of a wide band and a narrow band to determine the laser oscillation wavelength, the residual excitation light processing mechanism, the polarization unification mechanism that makes the polarization direction linear, and the wavelength of the laser light generated from the rare earth fiber In the laser light source device composed of the wavelength conversion module for converting the light, the polarization unifying mechanism is realized by the fiber connection method, and propagates through one of the connected fibers to realize the single polarization. The amount of residual excitation light propagating to the other fiber is reduced by the residual excitation light processing mechanism. It is characterized by a door.

  A fiber laser that can prevent degradation and breakage of the fiber, which was a problem when generating high-power light, and can generate high-power laser light with stable linear polarization without using a polarizer. can do.

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

(Embodiment 1)
In the first embodiment, the single polarization mechanism is realized by the fiber fusion method, and the residual excitation light divergence / absorption mechanism allows the residual excitation light to be processed before reaching the fusion portion. The form which comprised the laser is shown.

  One example of this embodiment is shown in FIG. In a resonator constituted by a pair of fiber gratings 102 and 104 by exciting a double clad polarization-maintaining fiber 103 (in this embodiment, a fiber length of 10 m) doped with rare earth Yb as a rare earth in the pump LD 101. Laser light is oscillated. In this embodiment, a single emitter laser diode (maximum output 10 W) having an oscillation wavelength of 915 nm is used as the pump LD. In the fiber grating 102, germanium is added to the core portion of the double clad polarization maintaining fiber, the sensitivity to ultraviolet light is improved, and the polarization maintaining fiber formed with a grating has a center wavelength of 1064.0 nm, The reflection spectrum has a half-value width of 1 nm and a reflectance of 98%. In addition, the fiber grating 104 is formed by adding germanium to the core portion of a general single mode polarization maintaining fiber (core diameter: 6 μm, clad shape: 125 μm), with a center wavelength of 1064.1 nm and a reflection spectrum. A half width of 0.09 nm and a reflectance of 10% are used. Although it is possible to increase the length of the Yb-doped double clad polarization maintaining fiber by increasing the reflectance of the fiber grating 104, there is a limit to the improvement of the characteristics, which is not an effective measure. Further, narrowing the band is important for wavelength conversion, but there is a problem that it is difficult to narrow the band of the fiber grating 104 by increasing the reflectance. The single polarization mechanism (polarizer) 105 is used to change the polarization of light to be oscillated into a single polarization (linear polarization). Thereafter, the light is introduced into the SHG module by an optical polarization maintaining fiber that propagates the oscillated light at around 1064 nm, and 532 nm light is generated by the second harmonic generation. A connecting portion 110 between the Yb-doped double-clad polarization maintaining fiber and a general single-mode polarization maintaining fiber exists between the Yb-doped cladding pump fiber and the single polarization mechanism (polarizer) 105, and causes deterioration of the fiber. Therefore, by providing the pump light divergence / absorption mechanism 801, overheating of the fiber can be prevented.

  A method for causing the single polarization mechanism 105 to function by connecting the fibers (by connecting and fusing the fibers by 90 ° rotation in the axial direction) will be described below.

  A polarization-maintaining optical fiber having a fiber grating is connected to both ends of a rare-earth-doped clad pump fiber in which a rare-earth element is added to a polarization-maintaining optical fiber, and one end of the polarization-maintaining optical fiber at both ends is maintained. A single-polarized laser having a matching reflection wavelength by matching one of the two reflection wavelengths formed by the optical fiber with one of the two reflection wavelengths formed by the polarization maintaining optical fiber at the other end Light can be oscillated. In other words, by causing the fused portion of the fiber to function as a single polarization mechanism, a single-polarized fiber laser light source can be realized even with a configuration without a polarizer as a member.

  On the other hand, as a method of single polarization, the single polarization mechanism (polarizer) 105 can be substituted by connecting the fibers (by connecting and fusing the fibers by 90 ° rotation in the axial direction). However, at that time, it was newly observed that there is a problem that the polarization direction of the oscillated 1064 nm light fluctuates by providing a pump light divergence / absorption mechanism in the fusion splicing portion. The present invention proposes a countermeasure method.

  The mechanism for single polarization is described below. The double-clad polarization-maintaining fiber 111 and the single-mode polarization-maintaining 112 are optical fibers having birefringence characteristics in the core portion where the fundamental wave oscillated in the biaxial directions orthogonal to each other propagates. Two axes, ie, a slow axis (Slow axis) and a first axis (Fast axis) that define two polarization planes are formed. The fiber gratings 102 and 104 are formed by periodically changing the refractive indexes of the core portions of the double clad polarization maintaining fiber 111 and the single mode polarization maintaining 112 to form the grating. The fiber gratings 102 and 104 function as reflection mirrors for forming a resonator for the fiber laser 100 to oscillate. Here, the double clad polarization maintaining fiber 111 and the single mode polarization maintaining 112 in which the fiber gratings 102 and 104 are formed have light polarized in the Slow axis direction (referred to as Slow axis polarized light) as the Slow axis. Propagating while maintaining the specified plane of polarization. On the other hand, light polarized in the direction of the Fast axis (referred to as Fast axis light) is propagated while maintaining the plane of polarization defined by the Fast axis. The Slow axis and the Fast axis refer to polarization axes that are orthogonal to each other about the core portion on the cross section of the polarization maintaining optical fiber.

  A double clad polarization maintaining fiber 111 having a fiber grating 102 is connected to an excitation (pump) LD 101 at one end and a Yb-doped double clad polarization maintaining fiber 103 to the other end. This fiber grating 102 forms two reflection wavelength bands having wavelengths λ1 and λ2 (λ1 <λ2) as reflection center wavelengths, respectively, due to the birefringence of the polarization maintaining fiber. Reflects light of wavelength. The fiber grating 102 transmits the excitation light from the pump LD 101 and reflects light in the 1060 nm band (light reflected by the fiber grating 104) generated by the Yb-doped double clad polarization maintaining fiber 103. Here, the reflectance of the fiber grating 102 is desirably 99% or more in order to prevent the oscillated laser light from returning to the excitation LD.

  The double clad polarization maintaining fiber 111 in which such a fiber grating 102 is formed propagates the pumping light from the pump LD 101 to the Yb-doped double clad polarization maintaining fiber 103, and the Yb-doped double clad polarization maintaining fiber 103. The emitted light or the light reflected by the fiber gratings 102 and 104 is propagated while maintaining its polarization plane. Here, of the two reflection wavelength bands formed by the fiber grating 102, the reflection wavelength band having the wavelength λ1 as the reflection center wavelength is the reflection wavelength band of the light of the Fast axis, and the reflection wavelength having the wavelength λ2 as the reflection center wavelength. The band is a reflection wavelength band of light on the Slow axis.

  On the other hand, the polarization maintaining fiber 112 in which the fiber grating 104 is formed has one end connected to the Yb-doped double clad polarization maintaining fiber 103 and the other end serving as an output end. The fiber grating 104 forms two reflection wavelength bands having wavelengths λ3 and λ4 (λ3 <λ4) as reflection center wavelengths, respectively, and reflects light having a wavelength within the reflection wavelength band. Specifically, the fiber grating 104 transmits the laser light generated in the Yb-doped double clad polarization-maintaining fiber 103 to the output end side and emits the light emitted by the Yb-doped double-clad polarization-maintaining fiber 103 or The light reflected by the fiber grating 102 is reflected with a lower reflectance than that of the fiber grating 102 (for example, when generating light in the range of 1050 to 1100 nm: a reflectance of 20% or less). In this case, the fiber grating 104 functions as an output end reflector that forms a resonator of the fiber laser 100 and also functions as an output end. The single-mode polarization-maintaining optical fiber 112 formed with such a fiber grating 104 propagates the laser light oscillated by the Yb-doped double-clad polarization-maintaining fiber 103 to the output side, and also uses the Yb-doped double-clad polarization-maintaining fiber 103. The light emitted by the laser beam or the light reflected by the fiber gratings 102 and 104 is propagated while maintaining its polarization plane.

  Here, of the two reflection wavelength bands formed by the fiber grating 104, the reflection wavelength band having the wavelength λ3 as the reflection center wavelength is the reflection wavelength band of the light of the Fast axis, and the reflection wavelength having the wavelength λ4 as the reflection center wavelength. The band is a reflection wavelength band of light on the Slow axis.

  The polarization-maintaining fibers 111 and 112 formed with the fiber gratings 102 and 104 respectively have a birefringence characteristic in the core part in the biaxial directions (Slow axis direction and Fast axis direction) orthogonal to each other. For example, it may be a PANDA (Polarization maintaining AND Abduction reducing fiber) fiber in which stress applying portions are arranged on both sides of the core portion, or an elliptical clad polarization maintaining fiber.

  The Yb-doped double clad polarization-maintaining fiber 103 emits light using the pumping light oscillated by the pump LD 101 and amplifies the light repeatedly reflected between the fiber gratings 102 and 104 described above to laser light. Functions as an amplification medium for generating Specifically, the Yb-doped double clad polarization-maintaining fiber 103 is obtained by adding a rare earth element to the core portion of a PANDA type or elliptical clad type polarization-maintaining optical fiber, and two layers are formed on the outer periphery of the core portion. It has a double clad structure in which the clad portions are arranged. In other words, the Yb-doped double clad polarization maintaining fiber 103 has a polarization maintaining function for maintaining the polarization of propagating light (for example, slow axis light or fast axis light), and is similar to a clad pump fiber having a double clad structure. It has an optical amplification function.

  The Yb-doped double clad polarization maintaining fiber 103 has one end (excitation light input side) connected to the double clad polarization maintaining fiber 111 and the other end (laser light output side) connected to the polarization maintaining optical fiber 112. The In this case, the Yb-doped double clad polarization-maintaining fiber 103 is fusion-bonded to the double-clad polarization-maintaining optical fiber 111 at the connection portion 110a on the pumping light input side, and single-mode polarization at the connection portion 110b on the laser light output side. The holding optical fiber 112 is fusion-connected. In such a Yb-doped double clad polarization maintaining fiber 103, the pumping light transmitted through the double clad polarization maintaining fiber 111 emits light by exciting the rare earth element ions in the core, and this emitted light (spontaneous emission) Light) propagates to the fiber gratings 102 and 104. Further, the Yb-doped double clad polarization maintaining fiber 103 amplifies the light that repeatedly reflects between the fiber gratings 102 and 104, and as a result, generates laser light.

  The rare earth element added to the core portion of the Yb-doped double clad polarization maintaining fiber 103 is, for example, in place of Yb when the fiber laser 100 oscillates laser light in the 1.55 μm band (1520 to 1600 nm). Er may be added to Yb, or Yb when a laser beam having a wavelength in the range of 1000 to 1150 nm is oscillated. The rare earth element may be one containing erbium and ytterbium (Er—Yb).

  Here, the polarization maintaining fibers 111 and 112 respectively connected to both ends of the Yb-doped double clad polarization maintaining fiber 103 are in a positional relationship in which the Slow axis and the Fast axis are parallel to each other. That is, the Slow axis and Fast axis of the double-clad polarization maintaining fiber 111 are substantially the same as the Slow axis and Fast axis of the single mode polarization maintaining fiber 112 rotated 90 degrees about the core portion. The polarization-maintaining optical fibers 111 and 112 having such a positional relationship have two reflection wavelength bands having the wavelengths λ1 and λ2 as reflection center wavelengths and the wavelengths λ3 and λ4 as reflection center wavelengths. Match one of the two reflection wavelength bands. In this case, the fiber gratings 102 and 104 repeatedly reflect light having a reflection wavelength within the reflection wavelength band thus matched.

  The resonator formed using the fiber gratings 102 and 104 and the Yb-doped double clad polarization maintaining fiber 103 has a reflection wavelength within a single reflection wavelength band matched between the fiber gratings 102 and 104. The light is resonated at the resonance wavelength (that is, the resonance wavelength), and the light having the resonance wavelength is repeatedly reflected between the fiber gratings 102 and 104 and amplified by the Yb-doped double clad polarization maintaining fiber 103. As a result, this resonator oscillates the laser beam having this resonance wavelength (that is, the single polarized laser beam) with high output while maintaining a single polarized wave. The laser light oscillated by the resonator propagates through the single-mode polarization maintaining optical fiber 112 while maintaining a single polarization and transmits through the fiber grating 104 and is output. Specifically, when pump light of 900 to 980 nm is input to the resonator by the pump light source 101, single-polarized laser light having a resonance wavelength in the range of 1000 to 1150 nm is oscillated. By using the method described above, it is possible to realize a single-polarized laser beam that oscillates with an output of several tens of W, for example. Hereinafter, this method is referred to as 90 ° fusion (90 ° connection).

  At this time, the primary coat (resin coating) of the single mode polarization maintaining fiber is removed by about 10 cm, and a residual fundamental wave (wavelength of 915 nm) propagating through the clad portion is radiated by forming a coil shape (802 parts) having a diameter of about 30 mm. Let At this time, assuming that the pumping light is 10 W, the absorption amount of the double clad polarization maintaining fiber doped with Yb as a rare earth is 0.6 dB / m, so the pumping light of 7.5 W is absorbed with a fiber length of 10 m. As a result, 2.5 W of 915 nm light is emitted as the residual excitation light, and propagates through the single mode cladding. Here, the single mode fiber coil strand 802 is fixed to the anodized plate 803 and absorbs the emitted infrared light and converts it into heat. As this absorbing plate, an anodized aluminum plate was used. In the case of the conventional configuration shown in FIG. 1, when pumping with 15 W excitation light (915 nm) and the oscillated output of 1064 nm is 6.8 W, the connected portion / single is 20 minutes after continuous operation. Although the primary coating (coating) of the mode polarization maintaining fiber is overheated and the fiber is broken, the coating may be overheated even if the operation is continued for 20 hours or more by taking the countermeasure of Example 1 in this embodiment. Therefore, reliability can be improved. In addition, since the pump light with higher power can be pumped, the output of 1064 nm can be increased, and the output of the green light wavelength-converted therefrom can also be increased.

  However, when the pumping light is processed in the region of the single mode polarization maintaining fiber including the part fused by 90 °, the normal single mode fiber in which the pumping light cannot propagate from the double clad fiber capable of propagating the pumping light. It is clear that there is a problem that the polarization of the fundamental wave light that is emitted when the fusion part is heated and the emitted light is increased when the output is increased by increasing the amount of input excitation light. became. FIG. 9 shows a plot of the output fluctuation amount with respect to the time at that time. It can be seen from this plot that the output is reduced by about 8% at maximum and vibrates greatly. When the output vibrates by 8%, the output fluctuates by about 15% in the light after wavelength conversion, and when the output constant value control is applied, a large margin (output margin) is required for the maximum output. When the output margin is increased, the maximum output of the light source is limited, so that it is necessary to select a light source device that is larger than necessary. This is because the single mode fiber portion is heated, the refractive index difference (birefringence difference) between the Fast axis side and the Slow axis side of the polarization maintaining fiber changes, and the polarization rotates. It has become. When the fiber structures (refractive index structure / shape) to be fused are different as in this embodiment, or when the rotation error when the fusion direction is rotated by 90 ° becomes 1 ° or more, the fibers are fused. It was found that polarization fluctuations due to the refractive index and fiber shape variations that originally exist in the optical fiber become significant. In a general polarization-maintaining fiber fusion machine that recognizes the rotation angle of the polarization-maintaining fiber by image processing and performs fusion processing, the rotation error is in the range of 1 ° to 5 °. In order to achieve the following, a polarization plane recognition method other than image processing is required, which complicates the process.

  Therefore, in the present embodiment (FIG. 10), the portion where the excitation light is processed is closer to the excitation LD than the portion where 90 ° fusion is performed, so that the fusion portion is heated by the heat converted from the processed excitation light. It is prevented from being heated.

  Differences between the conventional example and the embodiment of the present application will be described with reference to FIGS. In the conventional example (FIG. 8), the pump light divergence / absorption mechanism 801 is a region where the coating of the single mode fiber including the connecting portion between the double clad fiber and the single mode fiber is peeled off. On the other hand, in this embodiment, the pump light divergence / absorption mechanism is arranged in a portion closer to the pumping laser diode than the connection point between the double-clad fiber and the single-mode fiber realizing the polarization unifying mechanism. It is a big difference.

  The resin layer constituting the coating of the double clad fiber is removed by about 10 cm, and a residual fundamental wave (wavelength 915 nm) propagating through the clad portion is radiated by forming a coil shape (802 parts) having a diameter of about 30 mm. At this time, assuming that the pumping light is 10 W, the absorption amount of the double clad polarization maintaining fiber doped with Yb as a rare earth is 0.6 dB / m, so the pumping light of 7.5 W is absorbed with a fiber length of 10 m. As a result, 2.5 W of 915 nm light is emitted as the residual excitation light. Here, the single mode fiber coil strand 802 is fixed to the anodized plate 803 and absorbs the emitted infrared light and converts it into heat. As this absorbing plate, an anodized aluminum plate was used. In this embodiment, it can be seen that the type of the fiber from which the coating is peeled and the position where the pump light divergence / absorption mechanism is arranged must be different.

  Specifically, by setting the residual excitation light reaching the 90 ° fusion part to 3% or less of the excitation light to be injected, there is a difference in fiber structure and a rotation error of 1 ° to 5 ° during fiber fusion. However, it was found that the polarization fluctuation can be reduced. FIG. 11 shows the output fluctuation amount with respect to time of the light source to which the present embodiment is applied. Compared with FIG. 9, the output fluctuation is suppressed within 2%, and the effect is confirmed.

  In order to reduce the effect of rotational errors during fiber fusion, the double-clad fiber and single-mode fiber to be fused must be designed in advance so that the refractive index distribution and the physical shape of the fiber are the same. desirable.

  Further, when the portion closer to the pumping LD than the portion to be fused at 90 ° for processing the pumping light is a double clad fiber, the outer clad of the double clad fiber is preferably a resin clad, It is desirable that the resin cladding is removed together with the fiber coating.

  If the diameter of the single-mode fiber coil wire 802 formed in a coil shape is too small, the loss of the generated 1064 nm light is increased, and the fiber strand (fiber without a resin coating for fiber coating is used). Is larger than 20 mm, and when it is 40 mm or more, the radiation of the residual fundamental wave is reduced. Therefore, it is preferably about 20-40 mm.

  As a second example of the first embodiment, a method of embedding a fiber strand portion in a high refractive material will be introduced.

  In the first embodiment, unnecessary excitation light is diverged in the air having a refractive index of 1 by increasing the bending curvature of a double-clad polarization maintaining fiber that acts as a multimode fiber for the excitation light. However, since there is a refractive index difference of about 1.4 between the clad of the double clad polarization maintaining fiber and air, it has a weak point that the divergence efficiency of the pumping light is poor. Therefore, the present embodiment is characterized in that the double clad polarization-maintaining fiber coil element wire 1202 is covered with a material 1203 having a refractive index of 1.5 or more to actively extract the excitation light. Yes. As a material having a refractive index of 1.5 or more, silicone oil (or silicone gel) or the like used as a refractive index matching liquid has been conventionally used. However, since it is a liquid, it is difficult to hold and there is a risk of liquid leakage. there were. Therefore, in this embodiment, a silicone-based ultraviolet curable resin or a thermosetting resin (for example, Shin-Etsu Chemical Opticlear (n = 1.52 or so)) is used. In addition, an epoxy-based ultraviolet curable resin can be used if the refractive index is 1.5 or more.

  FIG. 12 shows a configuration diagram of a fiber laser wavelength conversion green light source in the present embodiment. The difference from the first embodiment is that the strand 1202 is made by stripping the coating of the double-clad polarization maintaining fiber other than the connection point between the double-clad fiber and the single-mode fiber realizing the polarization unification mechanism. Is embedded in a material having a refractive index of 1.5 or more. Usually, the primary coat covering the double clad polarization maintaining fiber is also made of a material having a refractive index of 1.4 or less. However, in this embodiment, it has a thickness of 1 mm or more from the outer periphery of the fiber strand. The effect of pulling out the remaining excitation light is realized by covering with a resin having a refractive index of 1.5 or more. The refractive index compensation resin 1203 covering the fiber is poured into an anodized aluminum container 1204, and the double clad polarization-maintaining fiber coil strand 1202 is embedded so as not to include the fiber connection portion, and then solidified. The dimension of the region into which the resin was poured in this example was a region of length x depth x depth = 50 mm x 5 mm x 1 mm. The length x depth is preferably as large as possible, but it is preferably in the range of 50 mm x 5 mm to 50 mm x 10 mm in order to increase the size of the apparatus. In this way, it is possible to efficiently extract the remaining excitation light by filling with a material whose refractive index is larger than that of the cladding of the fiber. In addition, the remaining excitation light can be spread over a wide area to prevent overheating and as heat. Has the role of facilitating divergence.

  In this embodiment, since the energy of the remaining excitation light is converted into heat, the temperature inside the housing of the fiber laser rises by 3 to 5 degrees. Therefore, as the temperature rises, the reflection wavelength of the fiber grating that determines the oscillation wavelength provided on the emission side shifts to the long wavelength side at a rate of 0.01 nm / ° C. as a typical value. This wavelength shift causes a decrease in green light output when green light is generated by wavelength conversion. Therefore, it is desirable to hold the fiber grating itself on a substrate that is thermally contracted as the temperature rises (using a temperature compensation package), and to place the fiber grating outside the housing. Even when the fiber grating is disposed in the housing, it is desirable that the fiber grating is disposed below the pump light divergence / absorption mechanism of the present invention as a heat source and is thermally separated.

  In order to improve the effect, it is desirable to dispose the pump light divergence / absorption mechanism on a heat radiating fin or the like and cool it using a cooling fan or the like.

  In addition, it is desirable that the fusion splicing portion in which the single polarization mechanism is realized has a structure that is difficult to be subjected to stress such as distortion and torsion. An example of the configuration is shown in FIG.

  In the fusion holding part, the fused fiber has a structure in which the fiber is fixed to a holder 1301 provided with a groove through which the fiber is passed with an adhesive 1303 and no stress is applied to the fusion connection part 410. It was confirmed that the distance between the portions fixed with the adhesive was 50 mm or more, and the effect of reducing the stress on the fused portion was obtained. Moreover, it is desirable that it is 100 mm or less from the viewpoint of miniaturization of the apparatus. Further, the fusion splicing portion 410 from which the fiber coating has been peeled is filled with a gas 1302 and sealed with a lid of the holder 1301. A chemical filter 1304 that adsorbs moisture in the air is provided inside the holder 1301. With this structure, it is possible to prevent the performance of the single polarization mechanism realized at the fiber fusion part from being deteriorated by stress on the fiber.

(Embodiment 2)
As a second embodiment of the present invention, a lens system is used between a rare-earth-doped double clad polarization maintaining fiber and a single mode polarization maintaining fiber, and a laser beam is once emitted into a space, and a converging beam of excitation light and oscillation light. We propose a method of making a single polarization by reducing the excitation light by making use of the difference in diameter and by making the axes of the fibers orthogonal.

  FIG. 14 shows a configuration diagram of a wavelength conversion type light source using a fiber laser in the present embodiment. The laser resonator is composed of a pair of fiber gratings 102 and 104 and a Yb-doped double clad polarization-maintaining fiber 103 that is a laser active material, and the configuration for pumping by the pump LD 101 is exactly the same as in the first embodiment. is there. In the present embodiment, a pump light divergence / absorption mechanism 1401 configured of a lens system and a pumping light absorption unit is provided at a portion where the type of fiber is switched from a double clad polarization maintaining fiber to a single mode polarization maintaining fiber. Is different.

  The excitation light absorption mechanism in this embodiment will be described with reference to FIG.

  The pump light divergence / absorption mechanism 801 includes a double clad polarization maintaining fiber 1402, a collimator lens 1403, a residual excitation light absorbing unit 1404, a coupling lens 1405, and a single mode polarization maintaining fiber 1406. In the case of this embodiment, the core diameter of the double clad polarization maintaining fiber 1402 is 6 micrometers, the diameter of the inner clad through which excitation light propagates is 105 micrometers, and the diameter of the outer clad is 125 micrometers. The single-mode polarization maintaining fiber 1406 has a core diameter of 6 micrometers and a cladding diameter of 125 micrometers. FIG. 15 shows an enlarged view. At this time, the oscillating light (1060 nm band in the case of the present embodiment) passing through the core diameter portion of 6 micrometers and the excitation light (915 nm band) passing through the inner cladding part of 105 micrometers pass through the collimator lens 1403. Thus, by utilizing the difference in beam diameter when the light becomes parallel light, unnecessary excitation light 1501 is absorbed by the residual excitation light absorption unit 1404 and removed. Specifically, the beam diameter of the parallel light (collimated beam) in the oscillation light 1502 is 200 μm. However, since the beam diameter of the excitation light 1501 is 430 μm, the excitation light absorbing portion in which a pinhole of about 250 μm is formed. By providing 1404, it can be absorbed and converted into thermal energy. The converted thermal energy is dissipated and dissipated to the housing 1407 holding the lenses 1403 and 1405. The oscillation light that has passed through the slit is again coupled to the single-mode polarization maintaining fiber 1406 by the coupling lens 1405 and guided through the core portion of the fiber. By adopting the structure described above, the remaining fundamental wave can be shielded, and the problem of fiber deterioration can be avoided.

  In addition, when realizing a single polarization by a method in which the axial direction of the polarization maintaining fiber is orthogonal (the fast axis and the slow axis of the polarization maintaining fiber are matched and optically connected), the fiber is heated. The birefringence of the fiber changes, the polarization plane moves, and the output after wavelength conversion fluctuates, so that the heat energy converted by the pumping light absorber is insulated so that it is not transmitted to the polarization maintaining fiber. desirable.

  When assembling the pump light divergence / absorption mechanism 1401 described here, it is necessary to perform alignment so that the transmission amount of the oscillation light propagating through the single mode core is maximized, but a conventional separation mirror is inserted. Compared to the case, it is only necessary to observe the amount of transmitted light as an adjustment guideline, and thus the adjustment cost can be reduced. In use, when pumping with excitation light of 10 W, the main body housing 1407 generates 2.5 W of heat, so it is necessary to provide a heat dissipation mechanism such as a heat dissipation fin. At the time of 10 W excitation, only the heat radiation fin for the CPU may be used. However, when the excitation light quantity is 20 W or more, it is desirable to cool the heat radiation fin to which the pump light divergence / absorption mechanism 1401 is fixed with a fan motor or the like.

(Embodiment 3)
As a third embodiment of the present invention, a lens system is used between the double clad polarization maintaining fiber 1402 and the single mode polarization maintaining fiber 1406, and the laser beam is once emitted into the space and perpendicular to the dielectric multilayer mirror 1602. , The pump light 1501 and the oscillation light 1502 are separated, and the pump light 1501 is returned to the double clad polarization maintaining fiber 1402 again.

  The laser resonator is composed of a pair of fiber gratings 102 and 104 and a Yb-doped double clad polarization-maintaining fiber 103 that is a laser active material, and the configuration for pumping with the pump LD 101 is exactly the same as in the first embodiment. is there. In the present embodiment, a pumping light reflecting mechanism 1601 composed of a lens system and a dielectric multilayer mirror 1602 is provided at a portion where the type of fiber is switched from the double clad polarization maintaining fiber 1402 to the single mode polarization maintaining fiber 1406. The place is different.

  The excitation light reflection mechanism in the present embodiment will be described with reference to FIG.

  The pumping light absorption mechanism includes a double clad polarization maintaining fiber 1402, a collimator lens 1403, a dielectric multilayer mirror 1602, a coupling lens 1405, and a single mode polarization maintaining fiber 1406. In the case of this embodiment, the core diameter of the double clad polarization maintaining fiber 1402 is 6 micrometers, the diameter of the inner clad through which excitation light propagates is 105 micrometers, and the diameter of the outer clad is 125 micrometers. The single-mode polarization maintaining fiber 1406 has a core diameter of 6 micrometers and a cladding diameter of 125 micrometers. At this time, by disposing a dielectric multilayer mirror 1602 that reflects the 915 nm band light and transmits the 1064 nm band light in a region where the oscillation light 1502 existing between the collimator lens 1403 and the coupling lens becomes parallel light. Only light in the 1064 nm band can be coupled to the single mode polarization maintaining fiber 1406. On the other hand, the reflected light in the 915 nm band is incident again from the collimator lens 1403, and is coupled and guided again to the double clad polarization maintaining fiber 1402. As a result, the 915 nm light that has become the residual pumping light is again absorbed by the double-clad polarization maintaining fiber 1402 and 94% of the pumping light (9.4 W in the case of 10 W pumping) is absorbed while reciprocating through the fiber. . In the case of the present embodiment, light that has once passed through the double-clad polarization maintaining fiber 1402 is returned again to the double-clad polarization maintaining fiber 1402 and reabsorbed, so that the loss of pumping light can be reduced. The efficiency (light-light conversion efficiency) when obtaining oscillation light can be improved.

  As another example of this embodiment, the dielectric multilayer mirror 1602 is inserted between the collimator lens 1403 and the coupling lens 1405 for coupling the oscillation light 1502 to the single mode polarization maintaining fiber 1406 again. By providing a collimating lens 1702 with a reflecting film that reflects 915 nm on the surface of the lens 1403, it is not necessary to separately arrange the dielectric multilayer mirror 1002 (FIG. 17). When this method is used, the alignment of the remaining excitation light can be completed automatically only by performing the lens alignment, and the adjustment of the mirror angle becomes unnecessary. Therefore, there is an advantage that the adjustment process can be simplified.

  As another method, a glass or zirconia ferrule 1802 used for an optical fiber connector or the like is used to hold the tip of the double clad polarization maintaining fiber 1402 and the held end face is polished, and the portion is reflected at 915 nm. , A method of forming a dielectric multilayer film mirror 1803 that transmits 1064 nm may be used (FIG. 18). Also in this case, since the mirror is provided on the fiber exit end face, the alignment of the mirror is unnecessary. If only the optical axis adjustment of the fundamental light source is aligned, the adjustment can be automatically completed without alignment of the remaining excitation light. It can be greatly simplified.

  In addition, when realizing a single polarization by a method in which the axial direction of the polarization maintaining fiber is orthogonal (the fast axis and the slow axis of the polarization maintaining fiber are matched and optically connected), the fiber is heated. The birefringence of the fiber changes, the polarization plane moves, and the output after wavelength conversion fluctuates, so that the heat energy converted by the pumping light absorber is insulated so that it is not transmitted to the polarization maintaining fiber. desirable.

  In addition, the arrangement | positioning method to the housing | casing of the fiber laser light source member in this invention is described. In the mechanism for absorbing / diverging / reflecting the remaining excitation light, in particular, the mechanism for absorbing / diverging, the energy of the remaining excitation light changed to heat is released. In FIG. 19, when the case of the fiber laser light source is represented by 1904, it is desirable that the pump LD 101 serving as a heat source and the mechanism 1901 for absorbing / diverging / reflecting the remaining excitation light be disposed as high as possible in the case. In particular, the fiber grating 104 disposed on the emission side of the oscillation light is desirably disposed above the laser diode 101 serving as a heat source or the mechanism 1901 that absorbs, diverges, and reflects the remaining excitation light, and is thermally separated. Is desirable. The reason for this is that the temperature inside the casing rises by about 10 ° C. from the heat generated from the two heat sources. For this reason, the reflection center wavelength of the fiber grating 104 is gradually shifted to a longer wavelength. It is desirable to speak from a heat source to avoid this long wavelength shift. In particular, FIG. 19A shows an example in which the temperature compensation mechanism 1902 is attached to the fiber grating 104 and disposed in the housing. FIG. 19B shows an arrangement schematic diagram in an example in which the fiber grating 104 is arranged outside the casing in order to thermally separate the temperature rise in the casing. Further, it is desirable to provide heat radiating fins and cooling fans in the vicinity of the heat source 1904. As described above, a completely air-cooled fiber laser fundamental wave light source that can also be used for wavelength conversion applications (0.01 nm or less) that have severe requirements for wavelength variation by adopting the member arrangement as shown in FIGS. 14 (a) and 14 (b). realizable. Although the temperature compensation package is effective, it is more desirable to dispose the fiber grating 104 outside the housing in view of cost.

  20 and 21 show a configuration example of a two-dimensional image display device using the fiber laser light source shown in the present invention.

  An example of the configuration of a laser display (image display device) to which the wavelength conversion module of the present invention is applied will be described with reference to FIG.

  FIG. 20 shows a schematic diagram of an optical engine of a projector system using a laser proposed in the present application as a light source. The two-dimensional image display device 2000 of the present embodiment is an example in which the contents of the present application are applied to an optical engine of a liquid crystal three-plate projector. Image processing unit 2002, laser output controller (controller) 2003, LD power supply 2004, red, green and blue laser light sources 2005R, 2005G, 2005B, beam forming rod lenses 2006R, 2006G, 2006B, relay lenses 2007R, 2007G, 2007B It is composed of folding mirrors 2008G and 2008B, two-dimensional modulation elements 2009R, 2009G and 2009B for displaying images, polarizers 2010R, 2010G and 2010B, a combining prism 2011 and a projection lens 2012.

  The green laser light source 2005G is controlled by a controller 2003 and an LD power source 2004 that control the output of the green light source.

  Laser light from each of the light sources 2006R, 2006G, and 2006B is shaped into a rectangle by rod lenses 2006R, 2006G, and 2006B, and the two-dimensional modulation elements of each color are illuminated by the relay lenses 2007R, 2007G, and 2007B. An image that is two-dimensionally modulated for each color is synthesized by a combining prism 2011 and projected onto a screen from a projection lens 2012 to display an image.

  In addition, the green laser light source 2005G uses a system in which the laser resonator is closed in the fiber, and suppresses a decrease in output over time and output fluctuation due to an increase in the loss of the resonator due to dust from the outside or a misalignment of the reflecting surface. be able to.

  On the other hand, the image processing unit 2002 plays a role of generating a light amount control signal for changing the output of the laser light in accordance with the luminance information of the input video signal and sending it to the laser output controller 2003. By controlling the amount of light according to the luminance information, the contrast can be improved.

  At this time, a control method (PWM control) in which the laser is pulse-driven and the average light quantity is changed by changing the duty ratio (lighting time / (lighting time + non-lighting time)) of the laser lighting time. ) Can also be taken.

  Further, the green light source used in the projector system may emit green laser light having a wavelength of 510 nm to 550 nm. With this configuration, green laser output light with high visibility can be obtained, and a color expression close to the primary color can be expressed as a display with good color reproducibility.

In order to achieve the above object, a two-dimensional image display device of the present invention includes a screen,
The laser light source includes a plurality of laser light sources and a scanning unit that scans the laser light source, and the laser light source includes a light source that emits at least each of red, green, and blue. It is good also as a structure using any one of these wavelength converters.

  With this configuration, it is possible to obtain green laser output light with high visibility, so that it can be used for a display having good color reproducibility and can express a color closer to the primary color.

  In addition to the form of projecting from behind the screen (rear projection display: FIG. 4), it is also possible to take a two-dimensional image display apparatus having a front projection type configuration.

  As the spatial modulation element, it is of course possible to use a two-dimensional modulation element using a transmissive liquid crystal or a reflective liquid crystal, a galvano mirror, or a mechanical micro switch (MEMS) represented by DMD.

  Note that, in the case of a light modulation element having a small influence of a polarization component on light modulation characteristics such as a reflective spatial modulation element, MEMS, and galvanometer mirror as in the present embodiment, when propagating a harmonic through an optical fiber, a PANDA fiber or the like Although it is not necessary to use a polarization-maintaining fiber, it is desirable to use a polarization-maintaining fiber when using a two-dimensional modulation device using liquid crystal because the modulation characteristics and polarization characteristics are greatly related.

  As shown in FIG. 21, as a form of display using a laser as a light source, a laser light source 2102 and a control unit 2103, a light guide member 2104 for converting the laser light source from a point light source to a line light source, and from a line light source to a surface light source. A light guide plate 2108 for converting and illuminating the entire surface of the liquid crystal panel, a polarizing plate / diffusion member 2109 for aligning the polarization direction and removing uneven illumination, a liquid crystal display 2107 composed of the liquid crystal panel 2110 and the like are realized. It is also possible to do. That is, the light source of the present invention can be used as a backlight light source for a liquid crystal display.

  Also, as shown in FIG. 22, the laser device of the present application is intended to irradiate a laser light source, a control unit for controlling the output from the laser light source, an output setting unit 2202 for setting the output, an output connector 2203 for outputting the laser light source, and laser light. It can also be used as a medical light source 2200 composed of a delivery fiber 2204 leading to an area, a handpiece 2205, and the like.

  By using the fiber laser light source of the present invention, it is possible to prevent fiber deterioration due to residual pumping light, which has been a problem with fiber laser light sources, particularly fiber laser light sources with a linear polarization of 1070 nm or less, and a simple method. Since single polarization is possible, reliability is improved, and excitation light output is not limited, so that the oscillation light output can be increased. In addition, by using a light source that combines this fiber laser light source and a wavelength conversion module, it can be applied to laser display devices having higher brightness and size than ever and having high color reproducibility. It becomes possible.

The figure which shows the fiber laser light source combined with the conventional 2nd harmonic generator Chromaticity diagram showing the relationship between the color of the light source and the color reproduction range Diagram related to oscillation light extraction method proposed in the conventional example Schematic diagram of the connection between the double clad polarization maintaining fiber and the single mode polarization maintaining fiber Plot showing absorption spectrum of Yb-doped double clad fiber Schematic diagram showing the configuration of a fiber laser light source realizing a single polarization method using a fiber connection method Schematic diagram showing the relationship between the reflection spectrum of the fiber grating and the oscillation wavelength Schematic diagram showing the case where a residual pumping light processing mechanism is applied to a fiber laser light source that realizes a single polarization method using a fiber connection method Plot diagram showing output fluctuation amount in one polarization component of the fiber laser of FIG. First example of Embodiment 1 of the present invention: Schematic diagram showing a case where a residual pumping light processing mechanism is applied to a fiber laser light source realizing a single polarization method by a fiber connection method 10 is a plot diagram showing the amount of output fluctuation in one polarization component of the fiber laser of the first embodiment of the present invention. Another example of Embodiment 1 of the present invention: Schematic diagram showing a case where a residual pumping light processing mechanism is applied to a fiber laser light source that realizes a single polarization method by a fiber connection method The schematic diagram which showed the holding method of the fiber connection part which implement | achieved single polarization in embodiment of this invention Example in Embodiment 2 of the present invention: Schematic diagram showing a case where a residual pumping light processing mechanism is applied to a fiber laser light source that realizes a single polarization method by a fiber connection method Example in Embodiment 2 of the present invention: Schematic diagram enlarging the residual excitation light processing mechanism portion Example 1 of Embodiment 3 of the present invention: schematic diagram enlarging the remaining excitation light processing mechanism part Second example in the third embodiment of the present invention: schematic diagram enlarging the remaining excitation light processing mechanism part Third example of Embodiment 3 of the present invention: schematic diagram enlarging the remaining excitation light processing mechanism part The schematic diagram which showed the arrangement position of the residual excitation light processing mechanism in the laser light source of this invention The schematic diagram which showed the structural example of the projector (projection display) to which the laser light source of this invention was applied The schematic diagram which showed the structural example of the liquid crystal display which applied the laser light source of this invention The schematic diagram which showed the structural example of the medical light source to which the laser light source of this invention was applied

Explanation of symbols

101 LD for pump
102 fiber grating 103 Yb-doped double clad polarization maintaining fiber 104 fiber grating 105 single polarization mechanism (polarizer)
106 Oscillating light propagation fiber 107 Second harmonic 108 SHG module (wavelength conversion mechanism)
109 Coating peeling part 110 Fusion splicing part 111 Double clad polarization maintaining fiber 112 Single mode polarization maintaining fiber 301 Pumping light source 302 Pumping light 303 Oscillating light 304 Lens 305 Mirror 306 Lens 307 Single mode rare earth doped fiber 401 Covering 402 Outer cladding 403 Inner clad 404 Single mode core 405 Single mode core 406 Cladding 407 Heat generating part 408 Coating 409 Residual excitation light 410 Fusion splicing part 801 Pump light divergence / absorption mechanism 802 Single mode fiber coil element wire 803 Anodized plate 1201 Pump light divergence absorption mechanism 1202 Double clad fiber coil strand 1203 Refractive index compensation resin 1204 Container 1301 Holder 1302 Gas 1303 Adhesive 1304 Cull filter 1401 Pump light divergence / absorption mechanism 1402 Double clad polarization maintaining fiber 1403 Collimator lens 1404 Residual excitation light absorption unit 1405 Coupled lens 1406 Single mode polarization maintaining fiber 1407 Case 1501 Excitation light 1502 Oscillation light 1601, 1701, 1801 Pump Light reflection mechanism 1602 Dielectric multilayer mirror 1702 Collimating lens with reflection film 1802 Ferrule 1803 Dielectric multilayer mirror

Claims (18)

A rare earth doped double clad fiber as a laser active material;
A pumping semiconductor laser for pumping a double clad rare earth doped fiber;
A pair of fiber gratings composed of a broadband fiber grating and a narrow-band fiber grating that determine the laser oscillation wavelength placed at both ends of a double-clad rare-earth doped fiber, a residual excitation light processing mechanism, and a polarization direction that is a linear direction In a laser light source device composed of a polarization unifying mechanism and a wavelength conversion module that converts the wavelength of laser light generated from a rare earth fiber,
The polarization unification mechanism is realized by the fiber connection method,
A laser light source characterized in that the residual pumping light processing mechanism reduces the amount of residual pumping light propagating through one of the fibers connected to realize a single polarization to the other fiber. The residual excitation light processing mechanism is
The laser light source according to claim 1, which has a function of converting light energy into heat energy. 2. The laser light source according to claim 1, wherein the residual excitation light processing mechanism is disposed at a position optically closer to the excitation semiconductor laser than the polarization unification mechanism. The residual excitation light processing mechanism is
The laser light source according to claim 1, wherein the laser light source uses a light reflection function. The laser light source according to claim 1, wherein an oscillation wavelength of the semiconductor laser for excitation is in a range of 900 to 950 nm. The laser light source according to claim 1, wherein the rare earth-doped double clad fiber has a polarization maintaining function. The laser light source according to claim 1, wherein the residual excitation light processing mechanism uses light radiation by a curvature of a fiber. 3. The laser light source according to claim 1, wherein, as the residual excitation light processing mechanism, a fiber portion that emits light is molded with a material having a refractive index of 1.5 or more. The laser light source according to claim 1, wherein the residual excitation light processing mechanism uses chromatic aberration between residual excitation light and oscillation light. The laser according to any one of claims 1 to 3, wherein a reflection mechanism is provided in the housing, the lens, and the fiber tip of the residual excitation light processing mechanism as the residual excitation light processing mechanism. light source. The laser light source according to any one of claims 1 to 3, wherein a reflection mechanism is provided in a double clad fiber as the residual excitation light processing mechanism. The laser light source according to claim 1, wherein the excitation light source or the residual light processing mechanism is disposed above the narrow-band fiber grating in the fiber laser device housing. 2. The laser light source according to claim 1, wherein the narrow-band fiber grating is disposed outside a fiber laser device housing. 12. The narrow band fiber grating is disposed inside a fiber laser device housing, and the narrow band fiber grating is provided with a temperature compensation mechanism. The laser light source described in 1. The laser light source according to any one of claims 1 to 14, wherein a fiber laser light source having an oscillation wavelength of 1030 to 1070 nm is used, and light having a wavelength of 515 to 535 nm is generated by wavelength conversion. A two-dimensional device comprising: the laser light source according to any one of claims 1 to 15, a laser output controller, a power supply device, a shaping optical system, a two-dimensional modulation element, and a projection lens. Image display device. It has the light source unit comprised from the laser light source of any one of Claims 1-15, and the control part of a laser light source, a light guide member, a polarizing plate, a diffusion member, and a liquid crystal panel. A two-dimensional image display device characterized by using a liquid crystal display device. A medical laser light source device comprising: the laser light source according to any one of claims 1 to 15; an output control unit for the laser light source; an output setting unit; and a fiber for outputting the laser light source. .

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