CN102494299A - Semiconductor laser illuminating source - Google Patents

Abstract

The invention discloses a semiconductor laser illumination light source. The semiconductor laser light source includes: a semiconductor laser, used to generate laser output; a beam collimation module, located at the back end of the optical path of the semiconductor laser, used to parallelize and collimate the laser output from the semiconductor laser; a spot homogenization module, located at the beam collimator The rear end of the optical path of the straight module is used to balance the beam quality in two directions perpendicular to each other in the cross section of the laser beam output by the beam collimation module, so as to realize the homogenization and recombination of the beam energy; the coupling output module is located at the spot homogenization module The rear end of the optical path is used to couple the homogenized and recombined laser output from the spot homogenization module. The semiconductor laser illumination light source of the present invention has the characteristics of strong adaptability, stable structure, reliable performance, etc., can realize uniform distribution of far-field laser spots, and enhance the clarity of long-distance observation targets.

Description

Semiconductor laser lighting source

technical field

The invention relates to the technical field of laser lighting in the optical industry, in particular to a semiconductor laser lighting source.

Background technique

Nowadays, semiconductor laser lighting sources are widely used, and they play a very important role as auxiliary lighting sources in the fields of community monitoring, forest fire prevention, navigation patrol and air rescue, and have huge market potential. Especially in the long-distance lighting conditions where the ambient illumination is low and the imaging quality is high, a large lighting field of view and clear imaging are essential prerequisites.

In the process of realizing the present invention, the applicant found that the semiconductor laser illumination light source of the prior art has the following technical defects: the uneven distribution of light intensity in the illumination field of view is caused by the uneven spatial distribution of laser multi-modes, resulting in a decrease in imaging quality, and thus imaging However, the clarity has not reached the best effect; in addition, for long-distance laser lighting, the adjustment of the field of view angle cannot accurately locate the specified target.

Contents of the invention

(1) Technical problems to be solved

In order to solve one or more of the above-mentioned problems, the present invention provides a semiconductor laser lighting source to achieve uniform distribution of far-field light beams, and realize long-distance uniform lighting and clear imaging.

(2) Technical solutions

According to one aspect of the present invention, a semiconductor laser illumination light source is provided. The light source includes: a semiconductor laser, used to generate laser output; a beam collimation module, located at the back end of the optical path of the semiconductor laser, used to parallelize and collimate the laser output from the semiconductor laser; a spot homogenization module, located in the beam collimation module The rear end of the optical path is used to balance the beam quality in two directions perpendicular to each other in the cross section of the laser beam output by the beam collimation module, so as to realize the homogenization and recombination of the beam energy; the coupling output module is located behind the optical path of the spot homogenization module The terminal is used to couple and output the homogenized and recombined laser output from the spot homogenization module.

In a preferred embodiment of the present invention, the light spot homogenization module includes: an upper multi-level plane reflector, located at the rear end of the optical path of the beam collimation module, and its lower reflector surface is at an angle of 45 degrees to the incident laser, for cutting and collimation The laser beam is divided into N parts; the lower multi-level plane mirror is vertically arranged with the first multi-level plane mirror, and its plane is at a 45-degree angle to the incident laser, used for translation of the collimated beam and recombination, so that the outgoing beam is transformed from a Gaussian beam with a Gaussian light energy distribution to a flat-hat beam with a uniform distribution.

(3) Beneficial effects

As can be seen from the foregoing technical solutions, the present invention has the following beneficial effects:

1. With the present invention, due to the use of the beam collimation module, under the action of the optically integrated collimating microlens, the divergent spot can be transformed into a parallel collimated spot, which reduces the divergence angle of the beam, thereby realizing the optical power enhancement of

2. Using the present invention, due to the use of the light spot homogenization module, the laser light energy is evenly distributed, reducing the influence of external stray light and the blurring of the field of view caused by the laser multi-mode feature, and improving the average brightness of the far-field light spot . Therefore, using the semiconductor laser light source after laser spot homogenization can achieve clear imaging of the specified target, which makes up for the shortcomings of the current long-distance imaging field of view, such as small field of view and poor contrast;

3. With the present invention, the optical fiber coupling module is used to soften the beam path. By utilizing this characteristic, the optical fiber can be coiled and fixed, which facilitates the layout and installation of various devices.

Description of drawings

Fig. 1 is the structural representation of semiconductor laser illumination light source of the embodiment of the present invention;

Fig. 2 is a system block diagram of a semiconductor laser lighting source according to an embodiment of the present invention;

3A is a schematic structural diagram of a spot homogenization module in a semiconductor laser illumination light source according to an embodiment of the present invention;

3B is a schematic diagram of the principle of spot homogenization of the spot homogenization module in the semiconductor laser illumination light source of the embodiment of the present invention;

3C is a schematic diagram of spot energy conversion of a spot homogenization module in a semiconductor laser illumination light source according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings. While illustrations of parameters including particular values may be provided herein, it should be understood that parameters need not be exactly equal to the corresponding values, but rather may approximate the values within acceptable error margins or design constraints.

In the present invention, the way of combining the array semiconductor laser and the multi-step plane reflector is adopted to achieve uniform distribution of far-field laser spots and enhance the clarity of long-distance observation targets.

In an exemplary embodiment of the present invention, a semiconductor laser illumination light source is provided. The semiconductor laser illumination light source includes: a semiconductor laser, a beam collimation module, a light spot homogenization module, a coupling output module and a driving circuit module. Fig. 1 is a schematic structural diagram of a semiconductor laser illumination light source according to an embodiment of the present invention. Fig. 2 is a system block diagram of a semiconductor laser illumination light source according to an embodiment of the present invention. The various components of the present invention will be described in detail below with reference to FIG. 1 and FIG. 2 .

As shown in FIG. 1 and FIG. 2 , the semiconductor laser in this embodiment is an array semiconductor laser, which can realize high-power laser output.

As shown in FIGS. 1 and 2 , the beam collimation module includes: an integrated aspheric microlens array 6 . According to the principle of optical refraction, the output beam of the laser will be transformed from a divergent elliptical spot into a parallel collimated linear spot after passing through the action of the microlens array.

Under the action of the beam collimation module, the divergent beam is converted into a parallel collimated beam, which reduces the divergence angle of the beam, thereby realizing the enhancement of the optical power density. After the light source is collimated, the spot diameter ω ₁ and the divergence angle θ ₁ after collimation are respectively given by the following relational formula:

ω ₁ = f·tanθ (1)

${\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In formulas (1) and (2), θ is the divergence angle before collimation, ω is the spot diameter before collimation, and f is the focal length of the beam expander collimator.

FIG. 3A is a schematic structural diagram of a light spot homogenization module in a semiconductor laser illumination light source according to an embodiment of the present invention. As shown in FIG. 3A , the light spot homogenization module is two multi-level plane mirror groups 7 . The two multi-echelon plane reflectors are arranged vertically and vertically, which can be called the lower multi-echelon reflector surface 2 and the lower upper multi-echelon reflector surface 1 . In addition, the mirror surfaces of the two reflectors are respectively at an inclination angle of 45 degrees to the vertical Y direction. The two multi-echelon plane reflector groups 7 are fixed by a metal frame device to form a multi-echelon reflector group arranged up and down separately.

3B is a schematic diagram of the light spot homogenization principle of the light spot homogenization module in the semiconductor laser illumination light source of the embodiment of the present invention. As shown in FIG. 3B , the two-axis beam quality obtained by the beam collimation module is not balanced, and the beam quality in the Y direction is much greater than that in the X direction. At this time, using the light spot homogenization module, the linear beam can be irradiated to the lower reflective mirror, the beam is divided into N parts, and then reflected to the upper reflective mirror. After being reflected by the upper reflector, N beams are shifted and beams are recombined, so that the parallel collimated linear spot is transformed into a rectangular spot.

3C is a schematic diagram of spot energy conversion of a spot homogenization module in a semiconductor laser illumination light source according to an embodiment of the present invention. As shown in FIG. 3C , after the function of the spot homogenization module, the beam quality in the Y direction is reduced to N times of the original, while the beam quality in the X direction is increased to 1/N times of the original. Through this process, the energy of the spot is redistributed, and the quality of the beam is balanced, so that the light energy distribution from the light source to the target is transformed from a Gaussian beam to a flat-top beam.

After the collimated beam passes through the spot homogenization module, the quality of the laser light source beam is balanced and the recombination of the beams in two directions is realized, so that the spot is homogenized and the imaging is clear. Before spot homogenization, the beam quality BPP _X , BPP _Y and the number of folding N in the two directions are given by the following formulas:

N ² =BPP _X /BPP _Y (3)

After the spot is homogenized, the beam quality of the laser light source in two directions satisfies the following relationship

BPP′ _X ＝BPP _X /N (4)

BPP′ _Y ＝BPP _Y ·N (5)

In formula (4) and formula (5), BPP′ _X is the X-axis beam quality after folding, and BPP′ _Y is the Y-axis beam quality after folding.

As shown in Figure 1 and Figure 2, the coupling output module includes: E2C (Ellipse to Circle) lens, aspheric focusing lens 11, multimode optical fiber 12, optical zoom lens 13. The laser light emitted by the above-mentioned spot homogenization module can transform the uniform square spot into a circular spot through the action of the E2C optical lens, and then the beam passes through the aspheric focusing lens 13 to converge the circular spot into a point spot. At this time, the multimode optical fiber 12 is placed at the front focal point of the focusing lens, so that the light beam is fully coupled into the optical fiber. Finally, the optical zoom lens 13 realizes the variable adjustment of the divergence angle of the optical fiber output beam. In the coupling output module, the optical path can be softened through the application of the optical fiber coupling module, which is convenient for the erection and adjustment of actual lighting. As shown in Figure 2, the E2C optical lens is a lens group composed of a plano-convex cylindrical lens, a concave-convex mirror and a plano-convex lens.

In this module, the light beam is transformed by the optical system, and when it is focused to the fiber, it must meet the requirement that the light source beam quality after folding is less than the fiber beam quality BPP _f , namely

$\sqrt{{\mathrm{<span\; class="notranslate">\; BPP</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; BPP</span>}}_{\mathrm{<span\; class="notranslate">\; Y</span>}}^{<span\; class="notranslate">\; \&prime;</span>\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; BPP</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

As shown in FIGS. 1 and 2 , the drive control circuit module is composed of a drive control circuit board 4 and a control unit 3 . The control unit 3 gives control commands to the drive circuit board 4 to achieve the required output laser power. Simultaneously, an electric signal can be given to the servo motor in real time to make the zoom objective lens in the optical zoom lens 13 move back and forth on the fixed guide rail to realize electronically controlled zooming, thereby adjusting the divergence angle of the outgoing light beam.

The overall frame (assembly method) of the semiconductor laser lighting source of the embodiment of the present invention is as follows: 1) connect the positive and negative ends of the laser light source module and the wiring of the optical zoom device to the laser control contact point on the drive module; 2) connect the light beam The collimation module is fixed on the front end of the laser light source module as required; 3) Place the fixed spot homogenization module frame at the specified distance from the beam collimation module, so as to realize beam homogenization and optical path deflection; 4) Focus E2C and aspheric surface The lens is placed on the bayonet of the lens fixture, and the corresponding horizontal position and height of the lens are adjusted at the same time, and fixed on the tray of the system device; at the focal point; 6) screw and fix the optical fiber output end to the socket of the optical zoom lens, and then use the double glued zoom objective lens to adjust the required beam irradiation angle; 7) use the metal shell 16 to adjust the entire light source system mechanical packaging.

The working process of the semiconductor laser lighting source in the embodiment of the present invention is as follows:

Step S01, input the electrical signal terminal into the light source system, and set the basic parameters of the driving circuit module according to the actual requirements of the system;

Step S02, the driving circuit module generates a driving control signal corresponding to the laser light source and the optical zoom according to the electrical signal instruction, and sends the signal to the laser light source and the optical zoom lens in real time;

Step S03, the laser light source receives the control signal sent by the drive circuit, generates a continuous optical signal according to the control command, and then the optical signal passes through the spot homogenization module to convert the irradiation light energy from a Gaussian beam to a uniformly distributed flat-top beam;

In step S04, the optical zoom system and the drive circuit implement synchronous information transmission, through the control command of the drive circuit, the mechanical transmission function of the optical zoom lens is realized, and then the observation angle of the field of view is adjusted to achieve the illumination positioning of the designated target object 7 .

In a semiconductor laser illumination light source entity prepared according to the present invention, the semiconductor laser light source is an array semiconductor laser light source with a wavelength of 808nm; the spot collimation module is an integrated microlens composed of an aspheric cylindrical lens and an aspheric microlens array The size of the array is 11.5mm(L)×1.5mm(H)×1.5mm(W) and 11.5mm(L)×1.5mm(H)×1.0mm(W), and the materials are N-LAF21 and SCHOTT ; In the spot homogenization module, the size of a multi-step plane mirror is 20mm (L) × 10mm (H) × 40mm (W); the fiber core diameter is 200 μm, and the numerical aperture NA is 0.22. The beam quality parameters of the entity after passing through each module are given below: First, before the beam collimation module, the beam quality of the array semiconductor laser light source in two directions is 0.7mm mrad and 1744mm mrad; after collimation, the beam quality is 0.7mm mrad mrad and 471.3mm mrad, the spot size at this time is 0.6mm×10.38mm; secondly, after the spot homogenization module, the spot size becomes 1.15mm×5.6mm after the spot is segmented, translated and combined; finally, After passing through the fiber optic module, the quality of the beam meets the conditions of the coupling fiber at this time, that is, the focal length f=15mm, the clear aperture d=6.35mm double glued focusing lens can focus to the fiber with a core diameter of 200μm and a numerical aperture NA=0.22. Subsequently, the optical zoom lens 13 is used to realize the adjustment of the field of view of the observation target.

To sum up, the semiconductor laser lighting source of the present invention has a precise and compact structure, which is easy to control and adjust, and is especially suitable for long-distance night vision lighting with high imaging quality requirements. Specifically:

(1) In the present invention, due to the use of the beam collimation module, under the action of the optically integrated collimating microlens, the divergent spot can be transformed into a parallel collimated spot, which reduces the divergence angle of the beam, thereby realizing the light beam power enhancement;

(2) In the present invention, due to the use of the light spot homogenization module, the laser light energy is evenly distributed, which reduces the influence of external stray light and the blurring of the field of view caused by the laser multi-mode feature, and improves the average light intensity of the far-field light spot. brightness. Therefore, using the semiconductor laser light source after laser spot homogenization can achieve clear imaging of the specified target, which makes up for the shortcomings of the current long-distance imaging field of view, such as small field of view and poor contrast;

(3) In the present invention, since the optical fiber coupling module is used, the beam path is softened, and the optical fiber can be coiled and fixed by using this characteristic, which facilitates the layout and installation of various components.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. a semiconductor laser lighting source is characterized in that, comprising:

Semiconductor laser is used to produce laser output;

The beam collimation module is positioned at the light path rear end of said semiconductor laser, is used for the parallel and collimation that carries out with said semiconductor laser output laser;

Hot spot homogenize module is positioned at the light path rear end of said beam collimation module, is used for the beam quality of the orthogonal both direction of cross section of the laser of said beam collimation module output is carried out equilibrium, realizes the homogenising reorganization of beam energy;

The coupling output module is positioned at the light path rear end of said hot spot homogenize module, is used for the laser coupled output after the homogenising reorganization of said hot spot homogenize module output.

2. semiconductor laser lighting source according to claim 1 is characterized in that, said hot spot homogenize module comprises:

Go up many echelons plane mirror, be positioned at the light path rear end of said beam collimation module, mirror surface and incident laser are miter angle under it, are used for cutting and collimated laser beam, and it is divided into N part;

Following many echelons plane mirror; Itself and said many echelons plane mirror are vertically to be enumerated; It is mirror surface and incident laser miter angle down; Be used for to be divided into the translation and the reorganization of the collimated light beam of N part, thereby make outgoing beam change equally distributed flat top beam into by the Gaussian beam that Gauss's luminous energy distributes.

3. semiconductor laser lighting source according to claim 2 is characterized in that,

Said hot spot homogenize module, also be used to make through its laser beam in the direction of propagation upper deflecting an angle of 90 degrees.

4. semiconductor laser lighting source according to claim 1 is characterized in that, said coupling output module comprises:

The E2C optical lens is positioned at the light path rear end of said hot spot homogenize module, is used for converting the square focus spot of said hot spot homogenize module output into circular light spot;

The aspheric surface condenser lens is positioned at the light path rear end of said E2C optical lens, is used for the laser of said E2C optical lens output is focused on, and the cross section of this laser converts a hot spot into by circular light spot;

Multimode fibre is positioned at the light path rear end of said aspheric surface condenser lens, and its incident end is positioned at the front focus place of said aspheric surface condenser lens, is used to carry the laser of said aspheric surface condenser lens output;

Zoom lens is positioned at the light path rear end of said multimode fibre, is used for the dispersion angle of said multimode fibre output laser beam being regulated output laser.

5. semiconductor laser lighting source according to claim 4 is characterized in that, said E2C optical lens is the set of lenses of being made up of plano-convex cylindrical mirror, concave and convex lenses and planoconvex lens.

6. semiconductor laser lighting source according to claim 1 is characterized in that, said beam collimation module comprises:

Aspherical microlens array, the light path rear end that it is positioned at said semiconductor laser is used for said semiconductor laser is exported laser is changed into collimate in parallel by the ellipse light spot of dispersing line style hot spot.

7. according to each described semiconductor laser lighting source in the claim 1 to 6, it is characterized in that said semiconductor laser is the array semi-conductor laser instrument.

8. according to each described semiconductor laser lighting source in the claim 1 to 6, it is characterized in that, also comprise:

Drive control module is connected with said coupling output module with said semiconductor laser, is used for sending first control signal to said semiconductor laser, makes its emission semiconductor laser; Send second control signal to said coupling output module, make it regulate the beam divergence angle of coupling output laser.

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