SEMICONDUCTOR LASER DEVICE AND OPTOELECTRONIC BEAM DEFLECTION ELEMENT FOR A SEMICONDUCTOR LASER DEVICE
20220255292 · 2022-08-11
Inventors
- Johann RAMCHEN (Hausen, DE)
- Andreas Fröhlich (Regensburg, DE)
- Martin Haushalter (Regensburg, DE)
- Jan MARFELD (Regensburg, DE)
- Massimo Cataldo Mazzillo (Regensburg, DE)
Cpc classification
H01S5/02234
ELECTRICITY
H01S5/02325
ELECTRICITY
International classification
Abstract
A semiconductor laser device is specified comprising an edge emitting semiconductor laser diode, which emits laser light along a horizontal direction during operation, a reflector element, which deflects a first part of the laser light in a vertical direction, while a second part of the laser light continues to propagate in the horizontal direction, and a detector element, which is arranged at least partly in a beam path of the second part of the laser light. An optoelectronic beam deflection element for a semiconductor laser device is furthermore specified.
Claims
1-6. (canceled)
7. An optoelectronic beam deflection element for a semiconductor laser device, comprising a semiconductor body (70) having a mounting surface, a front surface formed at an angle of 45° to the mounting surface, on which a reflector element formed by a mirror layer is applied, and a detector element formed in the semiconductor body on the side of the mirror layer facing the mounting surface, wherein the detector element is at least partially formed by a p-type region and an n-type region of the semiconductor body, the semiconductor body has, on the mounting surface and/or on at least one rear surface different from the mounting surface and the front surface, at least two electrical contact elements, at least one of which contacts the p-type region and at least one other of which contacts the n-type region, and at least one of the electrical contact elements is in electrical contact with an electrical through-connection extending from a rear surface or the mounting surface to the front surface.
8. The optoelectronic beam deflection element according to claim 7, wherein the semiconductor body comprises silicon.
9. The optoelectronic beam deflection element according to claim 8, wherein the front surface is formed by a crystal surface that deviates by 9.74° from the crystallographic 100-surface.
10. The optoelectronic beam deflection element according to claim 7, wherein the mirror layer comprises a metal and/or a dielectric layer sequence.
11. The optoelectronic beam deflection element according to claim 7, wherein a plurality of detector elements is formed in the semiconductor body.
12. A semiconductor laser device comprising: an edge-emitting semiconductor laser diode which emits laser light along a horizontal direction during operation; a reflector element which deflects a first portion of the laser light in a vertical direction while a second portion of the laser light continues to propagate in the horizontal direction; and a detector element which is arranged at least partially in a beam path of the second portion of the laser light, wherein at least part of the semiconductor laser diode and at least part of the detector element are covered with a non-transparent material.
13. The semiconductor laser device according to claim 12, wherein at least part of the semiconductor laser diode, at least part of the reflector element, and at least part of the detector element are covered with a transparent material.
14. The semiconductor laser device according to claim 12, wherein the non-transparent material completely covers the transparent material.
15. The semiconductor laser device according to claim 12, wherein the reflector element comprises two prisms with a dielectric layer arranged between them, and the dielectric layer is arranged at an angle of 45° to the horizontal direction.
16. The semiconductor laser device according to claim 15, wherein the semiconductor laser diode, the reflector element and the detector element are arranged on a common carrier, and a surface of the reflector element facing away from the carrier forms a light outcoupling surface of the semiconductor laser device.
17. The semiconductor laser device according to claim 1, wherein the reflector element and the detector element are integrated in an optoelectronic beam deflection element, said optoelectronic beam deflection element comprising: a semiconductor body having a mounting surface; a front surface formed at an angle of 45° to the mounting surface, on which a reflector element formed by a mirror layer is applied; and a detector element formed in the semiconductor body on the side of the mirror layer facing the mounting surface, wherein the detector element is at least partially formed by a p-type region and an n-type region of the semiconductor body, the semiconductor body has, on the mounting surface and/or on at least one rear surface different from the mounting surface and the front surface, at least two electrical contact elements, at least one of which contacts the p-type region and at least one other of which contacts the n-type region, and at least one of the electrical contact elements is in electrical contact with an electrical through-connection extending from a rear surface or the mounting surface to the front surface.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In the figures:
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
DETAILED DESCRIPTION
[0036] In the exemplary embodiments and figures, equal or similar elements or elements of equal function may each be provided with the same reference signs. The elements shown and their proportions to one another are not to be regarded as true to scale; rather, individual elements, such as layers, components, structural elements and areas, may be shown exaggeratedly large for better representability and/or for better understanding.
[0037]
[0038] A detector element 3 is arranged at least partially in a beam path of the second portion 12 of the laser light 10. While the first portion 11 is coupled out of the semiconductor laser device 100, the second portion 12 is used to measure the laser light intensity and/or intensity changes by the detector element 3, which for example comprises or is a photodiode.
[0039] The semiconductor laser diode 1 is based on, for example, one of In.sub.xGa.sub.yAl.sub.1-x-yAs, In.sub.xGa.sub.yAl.sub.1-x-yP, or In.sub.xGa.sub.yAl.sub.1-x-yN, depending on the desired wavelength of the laser light 10 as described in the general part above, with 0≤x≤1, 0≤y≤1, and x+y≤1 in each case. The semiconductor laser diode 1 can be designed as a continuously emitting laser diode or as a pulsed laser diode with a single active region or with a plurality of active regions, in particular in the form of a broad-strip laser.
[0040] The semiconductor laser diode 1, the reflector element 2, and the detector element 3 are jointly integrated in the semiconductor laser device 100. In particular, the semiconductor laser diode 1, the reflector element 2, and the detector element 3 may be arranged in a common housing 99 as shown. The housing 99, which may be, for example, a plastic housing, a ceramic housing, a metal housing, or a mixture thereof having lead frames and/or conductor paths, may be surface mountable, in particular, and have a mounting surface oriented perpendicular to the vertical direction 92. Accordingly, during operation, the semiconductor laser diode 1 emits the laser light 10 parallel to the mounting surface. The first portion 11 of the laser light 10 is emitted perpendicular to the mounting surface, so that the semiconductor laser device 100 may be a so-called top-looker package.
[0041] Further features and modifications of the semiconductor laser device 100 are explained in connection with the following figures. The description of the following figures mainly refers to differences and further developments compared to preceding exemplary embodiments. Features not described may therefore each be as embodied in preceding exemplary embodiments.
[0042]
[0043] In the exemplary embodiment shown, the semiconductor laser diode 1 is designed as a pulsed broad-strip multimode laser diode whose laser light 10 can exhibit a large divergence, as indicated by the dashed lines. However, due to the close spatial proximity of the semiconductor laser diode 1 to the reflector element 2, no further optical measures are necessary to collimate the laser light 10 prior to beam splitting.
[0044] In the exemplary embodiment shown, the reflector element 2 comprises two prisms 21 with a dielectric layer 22 arranged between them, the dielectric layer 22 being arranged at an angle of 45° to the horizontal direction 91. The prisms 21 are, for example, made with or of glass, such as borosilicate glass or quartz glass. The reflector element 2 may thus be formed of two interconnected glass prisms, which are connected to each other via the dielectric layer 22. Alternatively, the prisms 21 may comprise or be made of a plastic. At the interface between the prisms 21 the dielectric layer 22 is applied, the refractive index of which is selected in comparison with the refractive index of the prisms 21 such that the reflection of the first portion 11 and transmission of the second portion 12 described above are achieved. Accordingly, with respect to the first portion 11, the reflector element 2 causes the laser light 10 to be deflected by 90° and thus causes the beam formed by the first portion 11 to be coupled out of the semiconductor laser device 100.
[0045] The smaller second portion 12 of the laser light 10, which may for example be 1% of the laser light 10 generated by the semiconductor laser diode as described above, is transmitted through the dielectric layer 22. At least part of it can thus reach the detector element 3, which is mounted behind the reflector element 2 and which is preferably designed as a photodiode.
[0046] The semiconductor laser diode 1 and the detector element 3 are optically connected to the reflector element 2 with an optically transparent material 4. For this purpose, as shown in
[0047] Furthermore, a non-transparent material 5 is applied over the semiconductor laser diode 1, the detector element 3 and the transparent material 4, and preferably completely covers the aforementioned components as shown. In the shown exemplary embodiment, the non-transparent material 5 is a black epoxy and is applied, for example, by means of casting or a film-assisted molding method. The surface of the reflector element 2 facing away from the carrier 6 forms the light outcoupling surface 23 of the semiconductor laser device 100. The light outcoupling surface 23 is thus formed in particular by a surface of one of the glass prisms 21. The non-transparent material 5 is arranged laterally adjacent to the reflector element 2, the light outcoupling surface 23 being free of the non-transparent material 5 as well as the transparent material 4. As shown, the light outcoupling surface 23 and a surface of the non-transparent material 5 facing away from the carrier 6 form a common surface of the semiconductor laser device 100, which is particularly preferably a planar surface extending perpendicular to the vertical direction 92. Thus, the semiconductor laser device 100 has a continuous planar surface which may be advantageous, for example, with respect to common pick-and-place methods, while the semiconductor laser diode 1, the reflector element 2 and the detector element 3 are protected by the materials 4, 5.
[0048]
[0049] The optoelectronic beam deflection element 7 comprises a semiconductor body 70 having a mounting surface 71, a front surface 72, and rear surfaces 73 different from the mounting surface 71 and the front surface 72. Furthermore, the semiconductor body 70 has side surfaces parallel to the drawing plane. By means of the mounting surface 71, the beam deflection element 7 is mounted on the mounting surface of the carrier 6, for example by soldering or bonding, while the front surface 72, on which a mirror layer 74 forming the reflector element 2 is applied, is arranged facing the semiconductor laser diode 1. The semiconductor body 70 contains silicon and is formed, in particular, from a silicon wafer, as explained in more detail below in connection with
[0050] The mirror layer 74 forming the reflector element 2 comprises a metal and/or a dielectric layer sequence. The thickness of the metal and/or the dielectric layer sequence are selected such that the described partial reflection and partial transmission of the laser light 10 takes place for splitting the laser light 10 into the first and second portions 11, 12. Depending on the wavelength of the laser light 10, suitable metals include, for example, Al, Au, Ag as well as alloys therewith, wherein Al and/or Ag may be particularly suitable for visible light and Au may be particularly suitable for infrared light. Depending on the wavelength, combinations of metal and semimetal oxides and metal and semimetal nitrides such as SiO.sub.2, Si.sub.3N.sub.4, TiO.sub.2, Al.sub.2O.sub.3 are suitable as materials for the dielectric layer sequence.
[0051] The detector element 3 is formed in the semiconductor body 70 on the side of the mirror layer 74 facing the mounting surface 71, so that at least a part of the second portion 12 is irradiated onto the detector element 3. To form the detector element 3, the semiconductor body 70 has differently conductive regions 75, 76, one of which is p-type conductive and one of which is n-type conductive. For example, the region 75 corresponding to the semiconductor body 70 except for the region 76 may be n-conductive, while the region 76 is p-conductive. Reverse doping is also possible. In particular, the p-type region and the n-type region may form a photodiode as the detector element 3. For contacting the detector element 3, the beam deflection element 7 has contact elements (not shown).
[0052] As described, the optoelectronic beam deflection element 7 advantageously has a combination of the reflector element 2 and the detector element 3 in the same component, so that only one component to be mounted on the carrier 6 is necessary in addition to the semiconductor laser diode 1 for beam deflection and power measurement. This enables a compact design of the semiconductor laser device 100, since no additional space is required for the detector element 3. The adjustment of the radiation direction from the semiconductor laser device 100 and the detection of the laser light power is possible directly with the laser light beam emitted from the semiconductor laser diode 1, so that influences due to the housing geometry can be reduced compared to usual laser packages. By using the special crystal structure orientation of the semiconductor body 70 as described above, a high-precision 45° flank for forming the mounting surface 71 and thus a high-precision orientation of the reflector element 2 relative to the mounting surface 71 can be achieved, as is also described below. Here, a simple integration of a metallic or dielectric mirror is possible. Further features of the optoelectronic beam deflection element 7 will be explained in connection with the following figures.
[0053]
[0054]
[0055] For contacting the detector elements 3, the semiconductor body 70 correspondingly has a plurality of contact elements 77 and through-connections 78, which may be designed as in the previous exemplary embodiment. Here, as shown, the beam deflection element 7 may have a respective contact element 77 with an associated through-connection 78 for each region 76 and a common contact element 77 for contacting the region 75. Due to such a segmented photodiode, the beam deflection element 7 can be used with a plurality of semiconductor laser diodes on a common carrier, wherein separate detection and control of the different semiconductor laser diodes, for example with different wavelengths, is possible with small spacing on the same carrier or in the same housing.
[0056]
[0057] As shown in
[0058] At the first main surface 81, p-type regions 76 are produced. The regions 76 are produced, for example, by means of diffusion or implantation of a suitable dopant and, together with the region 75, form the previously described detector elements 3 in the subsequently completed beam deflection elements 7. By means of suitable structured doping, segmented photodiodes can also be produced, as described further above.
[0059] From the first main surface 81, the front surface 72 of the semiconductor bodies 70 is formed in the method described herein, as indicated in
[0060] In a further method step, as shown in
[0061] In a further method step, as shown in
[0062] As shown in
[0063] On the first main surface 81, as shown in
[0064]
[0065] The features and exemplary embodiments described in connection with the figures can be combined with each other according to further exemplary embodiments, even if not all combinations are explicitly described. Furthermore, the exemplary embodiments described in connection with the figures may alternatively or additionally have further features according to the description in the general part.
[0066] The invention is not limited to the exemplary embodiments by the description based on the same. Rather, the invention encompasses any new feature as well as any combination of features, which in particular includes any combination of features in the patent claims, even if this feature or combination itself is not explicitly stated in the patent claims or exemplary embodiments.