JP2006284856A - Multiplexing module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a multiplexing module to easily detect physical characteristics such as the quantities of projection lights from individual lasers with high precision and perform even real-time monitoring. <P>SOLUTION: The multiplexing module 1 is equipped with a light source array 10 where a plurality of lasers 11 are arranged, a collimator lens array 20 which collimates the luminous flux group LG emitted from the light source array 10 into pieces of parallel luminous flux by the pieces of emission luminous flux from the lasers 11, a condensing lens 30 which converges the luminous flux group LG emitted from the collimator lens array 20 together, and an optical fiber 40 on which the luminous flux group LG converged by the condensing lens 30 is made incident in a superposed state. A half-mirror 50 is provided between the condensing lens 30 and optical fiber 40 and a light receiving element array 60 which receives the luminous flux group LG reflected by the half-mirror 50 and detects physical characteristics of the pieces L1 to L7 of luminous flux from the lasers 11 is provided at a position not optically equivalent to a light incidence surface 40s of the optical fiber 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a multiplexing module that superimposes light emitted from a plurality of lasers and makes the light incident on a single optical fiber, and more particularly to a multiplexing module that can monitor the physical characteristics of light emitted from individual lasers. is there.

  A multiplexing module has been proposed in which light emitted from a plurality of lasers is superimposed and incident on one optical fiber to obtain a high-intensity fiber output. The multiplexing module includes, for example, a light source array in which a plurality of lasers are arrayed, a collimating lens array that converts a light beam group emitted from the light source array into a parallel light beam for each light beam emitted from the laser, and a light beam emitted from the collimating lens array. It is generally composed of a condensing lens for condensing the group collectively and an optical fiber on which the light flux group collected by the condensing lens is incident in a superimposed state.

  In the multiplexing module, it is preferable that physical characteristics such as the amount of light incident on the optical fiber are substantially constant over time. Conventionally, for example, a light receiving element is disposed between a condensing lens and an optical fiber to detect the amount of light emitted from the entire light source array, and one or more lasers forming the light source array so that the amount of light is substantially constant. Feedback control for adjusting the amount of emitted light is performed. However, such monitoring is extremely difficult to control, requires a complicated control circuit and the like, and has limited control accuracy. Further, since the light incident on the optical fiber is blocked while the light receiving element is disposed, the module must be turned off, and real-time detection cannot be performed.

  To control the physical characteristics of the light incident on the optical fiber over time, monitor the physical characteristics of the light emitted from the individual lasers in real time and control the light emitted from the individual lasers to be substantially constant. It is preferable to do.

Regarding the monitoring of the light quantity of the multiplexing module, (1) the physical characteristics of the emitted light from each laser is monitored by arranging a light receiving element behind each laser and detecting the emitted light behind the laser (Patent Document) 1), (2) A light receiving element is disposed between a condensing lens and an optical fiber, and a plurality of lasers are turned on sequentially in time to monitor physical characteristics of light emitted from each laser (Patent Document 2). Etc. have been proposed.
JP 7-326810 A JP-A-1-106486

  The multiplexing module described in Patent Document 1 detects the physical characteristics of the backward emitted light leaking behind the laser, and does not directly detect the physical characteristics of the forward emitted light that is incident on the optical fiber and that is originally desired to be detected. . In such a multiplexing module, the tendency of the physical characteristics of the backward emitted light and the forward emitted light does not necessarily match, and thus the detection accuracy is not good. In addition, it is necessary to provide a light receiving element for each laser, and it is difficult to reduce the size of the entire multiplexing module.

  In the multiplexing module described in Patent Document 2, it is necessary to sequentially turn on a plurality of lasers when performing light quantity monitoring, which takes time for detection and control. Also, real-time monitoring is not possible.

  It is also conceivable to change the configuration of the multiplexing module described in Patent Document 2 and arrange the light receiving element array between the light source array and the condensing lens instead of between the condensing lens and the optical fiber. In this case, since the amount of light is detected in a state where the light beams from the individual lasers are not superimposed, it is possible to independently detect the light beams from the individual lasers even when a plurality of lasers are turned on simultaneously. However, the diameter of the light beam group before condensing is large, and it is necessary to enlarge the light receiving element array accordingly, and it is difficult to downsize the entire multiplexing module. In addition, there is no change in that real-time detection is not possible.

  The present invention has been made in view of the above circumstances, and provides a multiplexing module that can easily and accurately detect physical characteristics such as the amount of light emitted from each laser and can also perform real-time monitoring. It is the purpose.

A first multiplexing module of the present invention includes a light source array in which a plurality of lasers are arranged, a collimating lens array that converts a light beam group emitted from the light source array into a parallel light beam for each light beam emitted from the laser, In a multiplexing module comprising: a condensing lens that collectively collects the light flux groups emitted from the collimating lens array; and an optical fiber on which the light flux groups collected by the condensing lens are incident in a superimposed state ,
Between the condensing lens and the optical fiber, a half mirror that partially transmits the light flux group to the optical fiber side and partially reflects to the side different from the optical fiber is provided,
The light flux group reflected by the half mirror is received at a position optically non-equivalent to the light incident surface of the optical fiber, and the physical characteristics of the light fluxes from the individual lasers forming the light flux group are detected. A light receiving element array including a plurality of light receiving elements is provided.

  In the first multiplexing module of the present invention, the light receiving element array has a position where an optical distance z from a position optically equivalent to the light incident surface of the optical fiber satisfies the following formula (1) or (2): And the pitch of the plurality of light receiving elements forming the light receiving element array is preferably set to be approximately equal to the pitch of the light beams from the individual lasers when entering the light receiving element array.

（式中、λはレーザ出射光の中心波長、ｗ_０は光ファイバの光入射面と光学的に等価な位置における光束の最小径を各々示す。） In the first multiplexing module of the present invention, “± of the optical distance z” means “−” when the light receiving element array is closer to the condensing lens than the optically incident position of the optical fiber. The case on the opposite side is defined as “+”.

(In the formula, λ represents the center wavelength of the laser beam, and w ₀ represents the minimum diameter of the light beam at a position optically equivalent to the light incident surface of the optical fiber.)

A second multiplexing module of the present invention includes a light source array in which a plurality of lasers are arranged, a collimating lens array that converts a light beam group emitted from the light source array into a parallel light beam for each emitted light beam from the laser, In a multiplexing module comprising: a condensing lens that collectively collects the light flux groups emitted from the collimating lens array; and an optical fiber on which the light flux groups collected by the condensing lens are incident in a superimposed state ,
The optical fiber has a light incident surface that is inclined with respect to the optical axis, and the light incident surface is a half mirror surface that partially transmits and partially reflects the light flux group. A light receiving element array comprising a plurality of light receiving elements for receiving the light flux group reflected by the surface and detecting the physical characteristics of the light fluxes from the individual lasers forming the light flux group is provided. It is.

In the second multiplexing module of the present invention, the light receiving element array is disposed at a position where an optical distance z from the light incident surface of the optical fiber satisfies the following formula (2), and the light receiving element array is It is preferable that the pitch of the plurality of light receiving elements to be formed is set to be approximately equal to the pitch of the light beams from the individual lasers when entering the light receiving element array.

(In the formula, λ represents the center wavelength of the laser beam, and w ₀ represents the minimum diameter of the light beam on the light incident surface of the optical fiber.)

  In the first multiplexing module of the present invention, a half mirror is provided between the condensing lens and the optical fiber so that the light beam group is partially reflected on the side different from the optical fiber, and optically incident on the light incident surface of the optical fiber. A light receiving element array that receives the light flux group reflected by the half mirror and detects the physical characteristics of the light fluxes from the individual lasers forming the light flux group is provided at non-equivalent positions.

  In such a configuration, since the same light flux group emitted from the light source array is incident on the optical fiber and the light receiving element array, the physical characteristics can be detected by the light receiving element array without stopping the light incident into the optical fiber. It can be implemented and real-time detection is possible.

  Since the light receiving element array is provided at a position optically non-equivalent to the light incident surface of the optical fiber, that is, at a position where at least the light beam center of each light beam is completely separated, one light receiving element array is provided. Therefore, the light beams from the individual lasers can be independently detected with high accuracy. Since the light receiving element array does not completely overlap the light beam group but can be arranged at a position where light is condensed to some extent, it is not necessary to use a large light receiving element array, and the entire module can be downsized.

  In the second multiplexing module of the present invention, the light incident surface of the optical fiber is a half mirror surface instead of providing a half mirror between the condenser lens and the optical fiber. In such a multiplexing module, the same luminous flux group emitted from the light source array is divided and made incident on the optical fiber and the light receiving element array, so that the light incident on the optical fiber is not stopped and the physical operation by the light receiving element array is stopped. Characteristics can be detected and real-time detection is possible.

  In the second multiplexing module of the present invention, the light receiving element array is inevitably optically non-equivalent to the light incident surface of the optical fiber, that is, a position where at least the light beam center of each light beam is completely separated. Therefore, the light beams from the individual lasers can be independently and accurately detected with a single light receiving element array. Since the light receiving element array does not completely overlap the light beam group but can be arranged at a position where light is condensed to some extent, it is not necessary to use a large light receiving element array, and the entire module can be downsized.

“First Embodiment”
A configuration of a multiplexing module according to the first embodiment of the present invention will be described with reference to the drawings. The present embodiment is provided with a mechanism for detecting in real time physical characteristics such as the amount of light emitted from each laser. FIG. 1A is an overall view of the multiplexing module, and FIGS. 1B to 1D show the condensing lens, the optical fiber, the light incident surface of the light receiving element array, and the incident light beam group forming the multiplexing module, respectively. (B) to (d) are shown in different scales.

  As shown in FIG. 1A, the multiplexing module 1 of the present embodiment includes a light source array 10 in which a plurality of lasers 11 are arranged and a light beam group LG emitted from the light source array 10 for each light beam emitted from the laser 11. The collimating lens array 20 that is parallel to the collimating lens, the condensing lens 30 that condenses the luminous flux group LG emitted from the collimating lens array 20, and the luminous flux group LG that is condensed by the condensing lens 30 are superimposed. And an optical fiber 40 that is incident on the line.

  The laser 11 is not particularly limited, and is GaN-based (370-450 nm), AlGaInP-based (580-690 nm), InGaP-based (650-1000 nm), AlGaAs-based (700-1000 nm), GaAsP-based (700-1000 nm), InGaAs-based. Examples thereof include semiconductor lasers such as (1000 to 3500 nm) and InAsP (1000 to 3500 nm). The numbers in parentheses indicate the oscillation wavelength range.

  The arrangement mode of the plurality of lasers 11 in the light source array 10 is not limited, and in the present embodiment, seven lasers 11 are arranged in the vertical direction in the figure. In the figure, the light beams from the individual lasers 11 forming the light beam group LG are denoted by reference symbols L1, L2,. Each light beam shape is illustrated in the case of an ellipse in which the arrangement direction (the vertical direction in the drawing) of the lasers 11 is a short axis and the depth direction in the drawing is a long axis.

The collimating lens array 20 is a lens array in which a plurality of collimating lenses 21 that are arranged at a number and a pitch corresponding to the plurality of lasers 11 and whose light incident surface and light emission surface are convex surfaces are integrated. The light beams L1 to L7 emitted from the collimating lens array 20 are all parallel light beams, and the optical axes of the light beams L1 to L7 are parallel to each other. As shown in FIG. 1B, the light beams L1 to L7 emitted from the collimator lens array 20 and incident on the condenser lens 30 are completely separated. The minor axis diameter (minimum diameter) w _x of each of the light beams L1 to L7 incident on the light incident surface 30s of the condenser lens 30 is, for example, on the order of several mm. The condensing lens 30 is a lens having substantially the same size as the collimating lens array 20 and having a light incident surface and a light exit surface that are convex, and the light incident on the optical fiber 40 at or near the focal length of the condensing lens 30. A surface 40s is arranged.

The optical fiber 40 is not particularly limited, and any type of glass fiber (such as quartz) and plastic fiber (such as (meth) acrylic) can be used. As the optical fiber 40, as shown in FIG. 1 (c), a single core type in which a core material 41 and a clad material 42 are laminated concentrically can be preferably used. A protective material (not shown) or the like is laminated on the outer peripheral side of the clad material 42 as necessary. The refractive index distribution of the core material 41 and the clad material 42 is arbitrary, and any of a step index type and a graded index type can be used. The transmission mode is also arbitrary, and either single mode or multimode can be used. As shown in FIG. 1C, in the present embodiment, the light beams L1 to L7 are configured to be incident on the core material 41 of the optical fiber 40 in a state where they are overlapped with each other. Minimum diameter _{w 0} of the light flux L1~L7 in the light incident surface 40s of the optical fiber 40 is several tens of μm order, for example.

  In the present embodiment, a half mirror 50 is provided between the condensing lens 30 and the optical fiber 40, and partially transmits the light flux group LG to the optical fiber 40 side and partially reflects to a side different from the optical fiber 40. Thus, the installation angle of the half mirror 50 is set. The light reflectivity of the half mirror 50 is not limited, and is designed within a range in which physical characteristics can be accurately detected by the light receiving element array 60 described later while sufficiently securing the amount of light incident on the optical fiber 40.

  In the present embodiment, the light beam group LG reflected by the half mirror 50 is received at a position optically non-equivalent to the light incident surface 40s of the optical fiber 40, and the light beams from the individual lasers 11 forming the light beam group LG are received. A light receiving element array 60 for detecting the physical characteristics of the light beams L1 to L7 is provided. The physical characteristics detected by the light receiving element array 60 are not limited, and examples include light quantity and noise. Examples of the light receiving element array 60 that detects the amount of light include a photodiode array.

  In the present embodiment, the light receiving element array 60 is located farther from a position 51 (a position where the light beam group LG converges, a convergence point) optically equivalent to the light incident surface 40 s of the optical fiber 40 when viewed from the half mirror 50. Is provided. That is, the light beam group LG reflected by the half mirror 50 is converged at a position 51 optically equivalent to the light incident surface 40 s of the optical fiber 40 and then enters the light receiving element array 60. The convergence state of the light beam group LG at the position 51 is the same as in FIG.

  The light receiving element array 60 can also be provided at a position closer to the position 51 optically equivalent to the light incident surface 40 s of the optical fiber 40 when viewed from the half mirror 50. However, in such a configuration, since the influence on the detection by the light receiving element array 60 of the light flux group LG from the condenser lens 30 toward the optical fiber 40 may not be ignored, the above configuration is more preferable.

  As shown in FIG. 1C, in the light receiving element array 60, a number of slits (light receiving portions) 61 corresponding to the number of lasers 11 are opened on the light incident surface 60s, and the light incident on each slit 61 is transmitted. A plurality of light receiving elements (not shown) for detecting physical characteristics are provided. Between the adjacent slits 61, 61 is a dead zone 62 where no light is received.

  Since the light receiving element array 60 is provided at a position optically non-equivalent to the light incident surface 40s of the optical fiber 40, the light beams L1 to L7 from the individual lasers 11 are in a state where at least the light beam centers are completely separated. The light enters the light receiving element array 60. At this time, the adjacent light beams L1 to L7 may partially overlap each other. The opening width d and the pitch p of the slits 61 of the light receiving element array 60 are designed so that the light beams L1 to L7 are received by different slits 61 and their physical characteristics are detected.

  In order to independently detect the light beams L1 to L7 with high accuracy, a light receiving element array is considered in consideration of a leakage amount (crosstalk) due to diffraction of light detected by an adjacent slit 61 when attention is paid to a specific slit 61. It is preferable to design the position 60, the opening width d and the pitch p of the slit 61, and the like. The pitch of the slits 61 (pitch of the light receiving elements) p is preferably set to be approximately equal to the pitch of the light beams L1 to L7 from the individual lasers 11 when entering the light receiving element array 60.

（式中、λはレーザ出射光の中心波長、ｗ_０は光ファイバの光入射面と光学的に等価な位置における光束の最小径を各々示す。） The inventor satisfies the following formula (1) or (2) so that the optical distance z from the position 51 optically equivalent to the light incident surface 40s of the optical fiber 40 of the light receiving element array 60 satisfies crosstalk. It has been found that the influence is sufficiently suppressed and the light beams L1 to L7 can be independently detected with high accuracy.

(In the formula, λ represents the center wavelength of the laser beam, and w ₀ represents the minimum diameter of the light beam at a position optically equivalent to the light incident surface of the optical fiber.)

Since the minimum diameters of the light beams L1 to L7 at the convergence point 51 are the same as the minimum diameters of the light beams L1 to L7 on the light incident surface 40s of the optical fiber 40, the same reference numerals (w ₀ ) are given.

  Hereinafter, the basis of the formula will be described in detail.

Assuming that the light beams L1 to L7 are completely separated, the minimum diameter w ₁ of the light beam at the position of the optical distance z from the convergence point 51 is expressed by the following equation (3). w _l increases in proportion to the absolute value of z.

（式（３）及び（４）中のｚは絶対値である。） Actually, the light beam group LG transmitted through the condenser lens 30 is in a state in which the light beams L1 to L7 are completely separated at a position away from the optical fiber 40, and is diffracted near the light incident surface 40s of the optical fiber 40. the minimum diameter of the affected light flux L1~L7 becomes larger than w _l, adjacent to the light beam are overlapped with each other. Considering the influence of diffraction, minimum diameter w _d of the light beam at the position of the optical distance z from the convergence point 51 is represented by the following formula (4).

(Z in the formulas (3) and (4) is an absolute value.)

For example, when a gallium nitride semiconductor laser (λ = 405 nm) is used as the laser 11, if the minimum diameter w ₀ of the light beams L ₁ to L 7 on the light incident surface 40 s of the optical fiber 40 is 10 μm, the optical distance z from the convergence point 51 is determined. The minimum diameter w ₁ of the light beam not considering diffraction and the minimum diameter w _d of the light beam considering diffraction are as shown in FIG. Further, the ratio _{w l} of _{w d η (w d / w} l) is as shown in FIG. 2 (b). In the figure, the unit of w and z is “mm”. As the absolute value of the optical distance z increases, the influence of diffraction decreases, and w _d approaches w _l . Although the case where z is “−” is illustrated, the same applies to the “+” side.

Pitch of the light beam L1~L7 varies proportionally with respect to not consider diffraction w _l as well as optical distance z. In order to efficiently take in the light beams L1 to L7 of the plurality of lasers 11 into the optical fiber 40, it is preferable that the light beams L1 to L7 are arranged as much as possible without gaps. Pitch of the light beam L1~L7 in the position of the optical distance z from the convergence point 51 is preferably set to about 2 × w _l.

  As shown in FIG. 2, when the optical distance z is in the vicinity of the convergence point 51, the value of η is large and the variation amount of η with respect to a minute change of z is large. This means that when focusing on a specific slit 61, the amount of leakage (crosstalk) due to diffraction of light detected by the adjacent slits 61 is large, and the amount is likely to fluctuate, which makes it difficult to measure with high accuracy. is doing.

In the example shown in the figure, when η = w _d / w ₁ is 1.2 or less, the crosstalk is small and the fluctuation amount with respect to z is also small. That is, w _d / w _l should satisfy the following formula (5).

From Expressions (3) to (5), Expressions (1) and (2) of the optical distance z satisfying η = w _d / _wl of 1.2 or less are obtained. That is, when the optical distance z satisfies the above formula (1) or (2), measurement can be performed within a range where η = w _d / _wl is 1.2 or less, and the influence of crosstalk is sufficient. The light beams L1 to L7 can be independently detected with high accuracy.

  The multiplexing module 1 of the present embodiment automatically adjusts the output and the like of each laser 11 based on the detection result of the light receiving element array 60, and changes the physical characteristics such as the amount of light emitted from each laser 11 over time. It is preferable to provide a control mechanism (not shown) for controlling substantially uniformly.

  The multiplexing module 1 of this embodiment is configured as described above.

  In the multiplexing module 1 of the present embodiment, a half mirror 50 is provided between the condenser lens 30 and the optical fiber 40 to partially reflect the light flux group LG on the side different from the optical fiber 40, and light incident on the optical fiber 40. A light receiving element that receives the light flux group LG reflected by the half mirror 50 at a position optically non-equivalent to the surface 40s and detects the physical characteristics of the light fluxes L1 to L7 from the individual lasers 11 forming the light flux group LG. The array 60 is provided.

  In such a configuration, the same light beam group LG emitted from the light source array 10 is separately incident on the optical fiber 40 and the light receiving element array 60, so that the light incident into the optical fiber 40 is not stopped and the light receiving element array 60 is stopped. The physical characteristics can be detected by real-time detection.

  The light receiving element array 60 is provided at a position that is optically non-equivalent to the light incident surface 40s of the optical fiber 40, that is, at a position where at least the light beam centers of the light beams L1 to L7 from the individual lasers 11 are completely separated. The single light receiving element array 60 can independently and easily detect the light beams L1 to L7 from the individual lasers 11 with high accuracy. Since the light receiving element array 60 is not completely superimposed on the light beam groups L1 to L7 but can be arranged at a position where light is condensed to some extent, it is not necessary to use a large light receiving element array 60 and the entire module can be downsized. It is.

  As described above, according to the multiplexing module 1 of the present embodiment, physical characteristics such as the amount of light emitted from each laser 11 can be detected easily and with high accuracy, and real-time monitoring is also possible.

“Second Embodiment”
A configuration of a multiplexing module according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is an overall view corresponding to FIG. 1A of the first embodiment. As in the first embodiment, this embodiment also includes a mechanism for detecting physical characteristics such as the amount of light emitted from each laser in real time, and the same reference numerals as those in the first embodiment denote the same reference numerals. The description is omitted.

  Similar to the first embodiment, the multiplexing module 2 of the present embodiment is generally configured by a light source array 10, a collimating lens array 20, a condenser lens 30, and an optical fiber 40. This embodiment is different from the first embodiment in that the half mirror 50 is not provided and the light incident surface 40s of the optical fiber 40 is a half mirror surface.

  Specifically, the optical fiber 40 has a light incident surface 40 s inclined with respect to the optical axis CL, and the light incident surface 40 s is a half mirror surface that partially transmits and partially reflects the light beam group LG. The light incident surface 40s is coated with a dielectric multilayer film or the like exhibiting half mirror characteristics. Further, the light incident surface of a general optical fiber is coated with an antireflection film for preventing normal light reflection. However, it is possible to obtain a half mirror surface only by removing this antireflection film.

  In the present embodiment, the light beam group LG reflected by the light incident surface 40s of the optical fiber 40 is received, and physical characteristics such as the light amounts of the light beams L1 to L7 from the individual lasers 11 forming the light beam group LG are detected. A light receiving element array 60 is provided.

  In the present embodiment, the light incident surface 40s of the optical fiber 40 is used as a half mirror surface, and the light beam group LG is partially transmitted into the optical fiber 40 and partially reflected, and the same light beam group emitted from the light source array 10 is used. LG is divided into the optical fiber 40 and the light receiving element array 60 to be incident. In such a configuration, the light receiving element array 60 is inevitably optically non-equivalent to the light incident surface 40s of the optical fiber 40, that is, a position where at least the light beam centers of the light beams L1 to L7 from the individual lasers 11 are completely separated. Therefore, the light beams from the individual lasers 11 can be independently detected by one light receiving element array 60.

  The configuration of the light receiving element array 60 and the state of the light beam group LG incident on the light receiving element array 60 are the same as in the first embodiment (see FIG. 1D). That is, a number of slits 61 corresponding to the number of lasers 11 are opened on the light incident surface 60s of the light receiving element array 60, and the light beams L1 to L7 are received by different slits 61 and their physical characteristics are detected. Thus, the opening width d and the pitch p of the slit 61 of the light receiving element array 60 are designed.

  As in the first embodiment, in order to independently detect the light beams L1 to L7 with high accuracy, the leakage amount (crosstalk) due to light diffraction detected by the adjacent slits 61 when focusing on a specific slit 61 is calculated. Considering the above, it is preferable to design the position of the light receiving element array 60, the opening width d and the pitch p of the slit 61, and the like.

（式中、λはレーザ出射光の中心波長、ｗ_０は光ファイバの光入射面における光束の最小径を各々示す。） The inventor of the present invention can sufficiently suppress the influence of crosstalk by allowing the optical distance z from the light incident surface 40s of the optical fiber 40 of the light receiving element array 60 to satisfy the following expression (2), and the light beams L1 to L7 can be reduced. It has been found that independent detection with high accuracy is possible.

(In the formula, λ represents the center wavelength of the laser beam, and w ₀ represents the minimum diameter of the light beam on the light incident surface of the optical fiber.)

  In the second embodiment, since the light flux group LG reflected by the light reflecting surface 40s of the optical fiber 40 does not converge, the light incident surface 40s of the optical fiber 40 of the light receiving element array 60 is used instead of the optical distance from the convergence point 51. The optical distance z from is used. As in the first embodiment, the position where the light beam group LG is converged (in this embodiment, the light incident surface 40s of the optical fiber 40) is the reference. As in the first embodiment, the optical distance z from the position where the light beam group LG of the light receiving element array 60 is converged satisfies the above formula (2), so that the light beams L1 to L7 can be independently detected with high accuracy. it can. In the second embodiment, since the light beam group LG reflected by the light reflecting surface 40s of the optical fiber 40 does not converge, only the expression (2) in which the optical distance z is “+” is provided.

  Also in the present embodiment, the output of each laser 11 is automatically adjusted based on the detection result of the light receiving element array 60, and the physical characteristics such as the amount of light emitted from each laser 11 are controlled substantially uniformly over time. It is preferable that a control mechanism (not shown) is provided.

  The multiplexing module 2 of this embodiment is configured as described above.

  In the multiplexing module 2 of this embodiment, instead of providing the half mirror 50 between the condenser lens 30 and the optical fiber 40, the light incident surface 40s of the optical fiber 40 is a half mirror surface. In such a multiplexing module 2, the same light flux group LG emitted from the light source array 10 is separately incident on the optical fiber 40 and the light receiving element array 60, so that light incidence into the optical fiber 40 is not stopped. The physical characteristics can be detected by the light receiving element array 60, and real-time detection is possible.

  In the multiplexing module 2 of the present embodiment, the light receiving element array 60 is inevitably optically non-equivalent to the light incident surface 40s of the optical fiber 40, that is, at least the center of the light beams L1 to L7 from the individual lasers 11. Therefore, the light beams from the individual lasers 11 can be independently detected with high accuracy by the single light receiving element array 60. Since the light receiving element array 60 can be arranged at a position where the light beam group LG is not completely superimposed but is condensed to some extent, it is not necessary to use a large light receiving element array 60 and the entire module can be downsized. .

  As described above, according to the multiplexing module 2 of the present embodiment, as in the first embodiment, physical characteristics such as the amount of light emitted from each laser 11 can be detected easily and with high accuracy, and real-time monitoring can be performed. Is also possible.

(Other aspects)
The present invention is not limited to the first and second embodiments described above, and the design can be changed as appropriate without departing from the spirit of the present invention. The arrangement of the lasers 11 and the emitted light beam shape in the light source array 10 can be designed as appropriate. For example, only the embodiment using the light source array 10 in which the lasers 11 are arranged in a single axis has been described.

  The multiplexing module of the present invention can be preferably used for applications such as optical communication, a laser processing machine, a light source for exciting a solid laser.

(A) is a general view of the multiplexing module of the first embodiment according to the present invention, and (b) to (d) are the condensing lens, the optical fiber, the light incident surface of the light receiving element array, and the incident light beam forming the multiplexing module. Plan view showing each group (A), (b) is a figure for demonstrating the suitable arrangement position of the light receiving element array in the multiplexing module of FIG. Overall view of a multiplexing module according to the second embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Combined module 10 Light source array 11 Laser 20 Collimating lens array 30 Condensing lens 40 Optical fiber 40s Optical fiber light incident surface 50 Half mirror 51 Position optically equivalent to optical fiber light incident surface 60 Light receiving element array L1 to L7 luminous flux LG luminous flux group

Claims (4)

A light source array in which a plurality of lasers are arranged, a collimating lens array that converts a light beam group emitted from the light source array into a parallel light beam for each light beam emitted from the laser, and the light beam group emitted from the collimating lens array In a multiplexing module comprising a condensing lens that collects light in a lump and an optical fiber on which the luminous flux group collected by the condensing lens is incident in a superimposed state,
Between the condensing lens and the optical fiber, a half mirror that partially transmits the light flux group to the optical fiber side and partially reflects to the side different from the optical fiber is provided,
The light flux group reflected by the half mirror is received at a position optically non-equivalent to the light incident surface of the optical fiber, and the physical characteristics of the light fluxes from the individual lasers forming the light flux group are detected. A multiplexing module comprising a light receiving element array including a plurality of light receiving elements. The light receiving element array is disposed at a position where an optical distance z from a position optically equivalent to the light incident surface of the optical fiber satisfies the following formula (1) or (2), and forms the light receiving element array: 2. The multiplexing module according to claim 1, wherein a pitch of the plurality of light receiving elements is set to be substantially equal to a pitch of the light flux from each of the lasers at the time of incidence on the light receiving element array.

(In the formula, λ represents the center wavelength of the laser beam, and w ₀ represents the minimum diameter of the light beam at a position optically equivalent to the light incident surface of the optical fiber.) A light source array in which a plurality of lasers are arranged, a collimating lens array that converts a light beam group emitted from the light source array into a parallel light beam for each light beam emitted from the laser, and the light beam group emitted from the collimating lens array In a multiplexing module comprising a condensing lens that collects light in a lump and an optical fiber on which the luminous flux group collected by the condensing lens is incident in a superimposed state,
The optical fiber has a light incident surface that is inclined with respect to the optical axis, and the light incident surface is a half mirror surface that partially transmits and partially reflects the light flux group,
A light receiving element array comprising a plurality of light receiving elements for receiving the light flux group reflected by the light incident surface and detecting physical characteristics of the light fluxes from the individual lasers forming the light flux group is provided. A multiplexing module. The light receiving element array is disposed at a position where an optical distance z of the optical fiber from the light incident surface satisfies the following formula (2), and the pitch of the plurality of light receiving elements forming the light receiving element array is the light receiving element. 4. The multiplexing module according to claim 3, wherein the multiplexing module is set to be approximately equal to a pitch of the light beams from the individual lasers at the time of incidence on the array.

(In the formula, λ represents the center wavelength of the laser beam, and w ₀ represents the minimum diameter of the light beam on the light incident surface of the optical fiber.)

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